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62Z7/67Z7/67TM7 SHOP MANUAL

93207-01080 September 2015

SHOP MANUAL WHEEL LOADER

General Information Function & Structure

62Z7/67Z7/ 67TM7 General Information Function & Structure

Printed in Japan (K) ( オセアニア用 )

93207-01080

93207-01080 September 2015

SHOP MANUAL (Function & Structure) INTRODUCTION ........................................................................................................................... IN-01~02 Symbol and Abbreviation ...............................................................................................................SY-1~2 SECTION 1

GENERAL

Group 1

Specifications .......................................................................................................... T1-1-1

Group 2

Component Layout .................................................................................................. T1-2-1

Group 3

Component Specifications ...................................................................................... T1-3-1

SECTION 2

SYSTEM

Group 1

Controller ................................................................................................................. T2-1-1

Group 2

Control System........................................................................................................ T2-2-1

Group 3

ECM System ........................................................................................................... T2-3-1

Group 4

Hydraulic System .................................................................................................... T2-4-1

Group 5

Electrical System..................................................................................................... T2-5-1

SECTION 3

COMPONENT OPERATION

Group 1

Pump Device ........................................................................................................... T3-1-1

Group 2

HST Motor ............................................................................................................... T3-2-1

Group 3

Multiple Control Valve ............................................................................................. T3-3-1

Group 4

Fan Motor and Fan Valve........................................................................................ T3-4-1

Group 5

Steering Valve ......................................................................................................... T3-5-1

Group 6

Priority Valve ........................................................................................................... T3-6-1

Group 7

Pilot Valve................................................................................................................ T3-7-1

Group 8

Brake Charge Valve ................................................................................................ T3-8-1

Group 9

Manifold Valve ......................................................................................................... T3-9-1

Group 10 Transmission ......................................................................................................... T3-10-1 Group 11 Axle ....................................................................................................................... T3-11-1 Group 12 Brake Valve ........................................................................................................... T3-12-1 Group 13 Ride Control Valve ................................................................................................ T3-13-1 Group 14 Others.................................................................................................................... T3-14-1 DIAGRAMS Electrical Connection Diagram Wiring Diagrams Hydraulic Circuit Diagram All information, illustrations and specifications in this manual are based on the latest product information available at the time of publication. The right is reserved to make changes at any time without notice.

62Z7/67Z7/67TM7

INTRODUCTION To The Reader This manual is written for an experienced technician to provide technical information needed to maintain and repair this machine.  Be sure to thoroughly read this manual for correct product information and service procedures.

Additional References Please refer to the other materials (operation and maintenance manual, parts catalog, engine technical material, Kawasaki shop materials, etc.) in addition to this manual.

Manual Composition  Information included in the Workshop Manual: Technical information needed for maintenance and repair of the machine, tools and devices needed for maintenance and repair, maintenance standards, and removal / installation and assembly / disassembly procedures.

Our shop manuals consist of the Technical Manual, the Workshop Manual and the Engine Manual.  Information included in the Technical Manual: Technical information needed for machine pre-delivery and delivery, operation and activation of all devices and systems, operational performance tests, and troubleshooting procedures.

 Information included in the Engine Manual: Technical information needed for machine pre-delivery and delivery and maintenance and repair of the machine, operation and activation of all devices and systems, troubleshooting and assembly / disassembly procedures.

Page Number Each page has a number, located on the center lower part of the page, and each number contains the following information: Example:  Technical Manual: T 1-3-5 T 1 3 5

 Workshop Manual: W 1-3-2-5 W 1 3 2 5

Technical Manual Section Number Group Number Consecutive Page Number for Each Group

IN-01

Workshop Manual (Disassembly & Reassembly) Section Number Group Number Sub Group Number Consecutive Page Number for Each Group

INTRODUCTION Safety Alert Symbol and Headline Notations In this manual, the following safety alert symbol and signal words are used to alert the reader to the potential for personal injury of machine damage.

d CAUTION:

Indicated potentially hazardous situation which could, if not avoided, result in personal injury or death.

d This is the safety alert symbol. When you see this

IMPORTANT: Indicates a situation which, if not conformed to the instructions, could result in damage to the machine.

symbol, be alert to the potential for personal injury. Never fail to follow the safety instructions prescribed along with the safety alert symbol. The safety alert symbol is also used to draw attention to component/part weights. To avoid injury and damage, be sure to use appropriate lifting techniques and equipment when lifting heavy parts.

f NOTE:

Indicates supplementary technical information.

Units Used SI Units (International System of Units) are used in this manual. MKSA (Meter, Kilogram, Second, Ampere) system units and English units are also indicated in parentheses just behind SI units.

Example: 24.5 MPa (250 kgf/cm2, 3560 psi) A table for conversion from SI units to other system units is shown below for reference purposes.

Quantity

To Convert From

Into

Multiply By

Length

0.03937

0.003281

US gal

0.2642

US qt

1.057

yd3

1.308

Weight

2.205

Force

kgf

0.10197

lbf

0.2248

Torque

N·m

kgf·m

Pressure

MPa

kgf/cm

MPa

psi

145.0

1.360

1.341

Temperature

°C

°F

°C×1.8+32

Velocity

km/h

mph

0.6214

min

rpm

1.0

L/min

US gpm

0.2642

mL/rev

cc/rev

1.0

Volume

Power

Flow rate

-1

fNOTE: The numerical value in this manual might be different from the above-mentioned table.

IN-02

0.10197 2

10.197

Symbol and Abbreviation Symbol and Abbreviation Symbol / Name Abbreviation T/M Transmission S/M Shop Manual

MC ECM VGS VGT

HST Controller

GSM

GPS CAN

A/C OPT MPDr. A/I, A/S WU Li ATT

Explanation

Transmission Shop manual (Function and Structure, Operational Performance Test / Troubleshooting, Disassembly and Reassembly). Main Controller Main controller. MC controls the engine, pump, and valve according to the machine operating condition. Engine Control Module Engine controller. ECM controls fuel injection amount according to the machine operating condition. Variable Geometry System controller Variable turbo controller. VGS is an exhaust turbo charged Variable Geometry Turbo controller system to supercharge the exhaust energy while running the engine at slow idle speed. VGS optimizes the turbine rotation, improves the performance at slow-speed torque and the acceleration, reduces fuel consumption, and reduces particulate matter (PM) by adjusting the nozzle opening of turbine housing. Hydrostatic Transmission Controller Hydrostatic transmission controller. Hydraulic pump and motors drive the clutch where all power is transmitted by hydraulic fluid. HST controller controls the transmission, HST pump and HST motors according to the machine operating condition. Global System for Mobile communications Communication controller. GSM is a type of wireless controller communication system, is used in more than on 100 countries around Europe and Asia, and becomes the factual global standards of the mobile telephone. Global Positioning System Global positioning system. Controller Area Network CAN communication. CAN is a serial communications protocol internationally-standardized by ISO (International Organization for Standardization). Air Conditioner Air conditioner. Option Optional component. Maintenance Pro Dr. MPDr. is software that troubleshooting, monitoring, and adjustment. Auto-idling Stop Auto-idling stop function Warming-Up Warming-up. Low (Slow) Idle Slow idle engine speed. Attachment Attachment.

SY-2

Symbol and Abbreviation Symbol / Name Abbreviation DPF Diesel Particulate Filter

DPD

Diesel Particulate Diffuser

DOC

Diesel Oxidation Catalyst

CSF

Catalyzed Soot Filter

PM EGR

Particulate Matter Exhaust Gas Recirculation

Explanation DPF is a filter which removes particulate matter (PM) including the toxic substance of exhaust gas of the diesel engine. Exhaust particulate removal equipment. DPD is an exhaust emission control system, a type of DPF, which cleans up particulate matter (PM) of diesel engine exhaust gas. DPD is a ceramic filter which traps and filters PM of exhaust gas. DPD burns up accumulated PM when PM increases and regenerates the filter. Oxidation catalyst for the diesel engine. Diesel oxidation catalyst oxidizes unburnt fuel and raises exhaust temperature. Filter. The filter traps, burns, and remove particulate matter (PM) by using high-temperature-exhaust gas with diesel oxidation catalyst. Catalyst is applied onto the filter. This advances PM burning. Particulate matter in gas The EGR control re-circulates a part of exhaust gas in the intake manifold and combines it with intake-air. Therefore, combustion temperature is lowered and generation of oxide of nitrogen (NOx) is controlled.

SY-2

SECTION 1

GENERAL CONTENTS Group 1 Specifications

Specifications (62Z7/67Z7)............................................... T1-1-1 Specifications (67TM7)....................................................... T1-1-2

Group 2 Component Layout

Main Component Layout (Overview)........................... T1-2-1 Main Component Layout (Hydraulic System)............ T1-2-3 Main Component Layout (Travel System)................... T1-2-5 Electrical System (Overview)........................................... T1-2-6 Electrical System (Cab)....................................................... T1-2-7 Front Console................................................................... T1-2-8 Right Console................................................................... T1-2-9 Rear Console..................................................................T1-2-11 Monitor Panel................................................................T1-2-12 Engine....................................................................................T1-2-13 Exhaust Filter.......................................................................T1-2-15 HST Pump, 4-Gear Pump Unit.......................................T1-2-16 Transmission, HST Motor.................................................T1-2-17 Control Valve.......................................................................T1-2-17 Manifold Valve.....................................................................T1-2-18 Brake Charge Valve............................................................T1-2-18 Fan Valve (for One Direction Rotation).......................T1-2-19 Fan Valve (with Fan Reverse Rotation).......................T1-2-19 Ride Control Valve..............................................................T1-2-20 Secondary Steering Block (Option).............................T1-2-21 Secondary Steering Pump (Option)............................T1-2-21 Solenoid Valve (In Front Chassis)..................................T1-2-22

Group 3 Component Specifications

Engine...................................................................................... T1-3-1 Engine Performance Curve (4HK1XZWT-01)........ T1-3-4 Engine Accessories.............................................................. T1-3-5 Hydraulic Component........................................................ T1-3-7 Electrical Component.......................................................T1-3-12

62Z7/67Z7/67TM7 (OCE)

(Blank)

62Z7/67Z7/67TM7 (OCE)

SECTION 1 GENERAL Group 1 Specifications Specifications (62Z7/67Z7)

45° I G B

40°

F D A

R1 R2

MNDF-12-001

Model Bucket Capacity: heaped Operating Weight Tipping Load (Full Turn) Engine A: Overall Length B: Overall Width (Bucket) C: Overall Height D: Wheel Base E: Tread F: Ground Clearance G: Bucket Hinge Height H: Dumping Clearance (45 °) I: Dumping Reach (45 °) R1: Minimum Rotation Radius R2: Minimum Rotation Radius Travel Speed Forward/Reverse Transmission Speeds (F/R) Articulation Angle (Left/Right) deg Tire Size

m3 (Y3) kg (lb) kg (lb)

62Z7 *2.1 (2.75) 11060 (24383) 7900 (17417) ISUZU 4HK1 7135 (281) 2560 (100.8) 3265 (128.5) 3000 (118) 1930 (76) 430 (17) 3805 (150) 2810 (110.6) 840 (33.1) 5085 (200) 5900 (232.3) 39 (24.2)/39 (24.2) 4/4 40 20.5-25-12PR (L2)

mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) km/h (mph) (°) -

fNOTE:  * BOC (Bolt-On Cutting Edge)  These specifications are subject to change without notice.

T1-1-1

67Z7 *2.4 (3.14) 11980 (26411) 8880 (19577) ISUZU 4HK1 7430 (292.5) 2560 (100.8) 3265 (128.5) 3000 (118) 1930 (76) 430 (17) 3835 (151) 2800 (110.2) 960 (37.8) 5085 (200) 5950 (234.3) 39 (24.2)/39 (24.2) 4/4 40 20.5-25-12PR (L2)

SECTION 1 GENERAL Group 1 Specifications Specifications (67TM7)

45°

H 50°

40° F R1

MNDF-12-003

Model Bucket Capacity: heaped Operating Weight Tipping Load (Full Turn) Engine A: Overall Length B: Overall Width (Bucket) C: Overall Height D: Wheel Base E: Tread F: Ground Clearance G: Bucket Hinge Height H: Dumping Clearance (45°) I: Dumping Reach (45°) R1: Minimum Rotation Radius R2: Minimum Rotation Radius Travel Speed Forward/Reverse Transmission Speeds (F/R) Articulation Angle (Left/Right) deg Tire Size

D A

m3 (Y3) kg (lb) kg (lb) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) km/h (mph) (°) -

Quick Coupler 2.1 (2.8) 12730 (28065) 7100 (15655) ISUZU 4HK1 7840 (309) 2560 (101) 3265 (128.5) 3000 (118) 1930 (76) 430 (17) 3970 (156) 2705 (106.5) 1350 (53) 5085 (200) 6020 (237) 39 (24.2)/39 (24.2) 4/4 40 20.5-25-12PR (L2)

fNOTE:  * BOC (Bolt-On Cutting Edge)  These specifications are subject to change without notice.

T1-1-2

General Purpose (Stock Pile) 2.4 (3.1) 12470 (27495) 7830 (17265) ISUZU 4HK1 7680 (302) 2560 (101) 3265 (128.5) 3000 (118) 1930 (76) 430 (17) 3970 (156) 2820 (111) 1245 (49) 5085 (200) 5980 (235) 39 (24.2)/39 (24.2) 4/4 40 20.5-25-12PR (L2)

SECTION 1 GENERAL Group 2 Component Layout Main Component Layout (Overview) 6

5 4 3 2 1

TNDF-01-02-001

123-

Bucket Bell Crank (Lever) Bucket Cylinder

56-

Head Light (Turn Signal Light/ Hazard Light/Clearance Light) (2 used) Front Work Light (2 used) Cab

78910-

T1-2-1

Lift Arm Cylinder (2 used) Lift Arm Bucket Link Hydraulic Oil Tank

TNDF-01-02-002

11- Rear Combination Light (Turn Signal/Hazard Light/Clearance Light/Brake Light/Backup Light) (2 used) 12- Rear Work Light (2 used)

SECTION 1 GENERAL Group 2 Component Layout  67TM7 Only

12 7 9

8 TNDF-01-02-021

TNDF-01-02-022

123-

Bucket Bell Crank (Lever) (2 used) Bucket Cylinder (2 used)

789-

Lift Arm Cylinder (2 used) Lift Arm Bucket Link (2 used)

12- Link (2 used) 13- Guide (2 used) 14- Quick Coupler Cylinder

T1-2-2

15- Quick Coupler

SECTION 1 GENERAL Group 2 Component Layout Main Component Layout (Hydraulic System) 1

7 8 9

12345678-

Ride Control Valve Steering Valve Pilot Valve Auxiliary Pilot Valve (Option) Priority Valve Hydraulic Oil Tank Air Cleaner Exhaust Filter

910111213141516-

11 23

Fan Motor Oil Cooler Radiator Intercooler Fuel Tank Fan Valve Coolant Reservoir Engine

10 20

17181920212223-

T1-2-3

18 17

16 15

HST Pump 4-Gear Pump Unit Manifold Valve Transmission Oil Filter HST Charge Filter Brake Charge Valve Service Brake Accumulator

TNDF-01-02-003

24- Secondary Steering Pump (Option) 25- Pilot Filter 26- Brake Valve 27- Control Valve 28- Ride Control Accumulator

SECTION 1 GENERAL Group 2 Component Layout  67TM7 Only

a a-

Front Side of Machine

29- Bucket Regenerative Selector Valve

Front Frame

30- Bucket Regenerative Valve

T1-2-4

TNDF-01-02-023

SECTION 1 GENERAL Group 2 Component Layout Main Component Layout (Travel System)

2 9 8 7

123-

Front Axle Steering Cylinder HST Motor 1

456-

Transmission Rear Propeller Shaft Rear Axle

789-

T1-2-5

Steering Accumulator HST Motor 2 Front Propeller Shaft

TNDF-01-02-010

SECTION 1 GENERAL Group 2 Component Layout Electrical System (Overview) 1

14 13

9 8

Electrical System (Cab) (Refer to T1-2-7)

Exhaust Filter (Refer to T1-215)

12-

Horn Lift Arm Proximity Switch, Lift Arm Angle Sensor (Option) MAF Air Cleaner Restriction Switch

56789-

Reverse Buzzer Battery Fuel Level Sensor Battery Relay Fusible Link (100A) (2 Used)

34-

7 6

10- Fusible Link A (65A) / Fusible Link B (65A) 11- Glow Plug Relay 12- Starter Relay 1 13- Hydraulic Oil Level Switch

T1-2-6

TNDF-01-02-011

14- Hydraulic Oil Temperature Sensor 15- Bucket Proximity Switch

SECTION 1 GENERAL Group 2 Component Layout Electrical System (Cab) Detail D

TNDB-01-02-032

Detail E

c TNDB-01-02-029

13 14

15 TNDF-05-04-002

Components Related with Front Console (Refer to T1-2-8)

Components Related with Right Console (Refer to T1-2-9)

Rear Console (Refer to T1-2-11)

1234-

Radio Upper Switch Panel (Option) Speaker Rear Wiper Motor

5678-

Accelerator Pedal Sensor Brake Angle Sensor Brake Light Switch Front Wiper Motor

9101112-

Air Conditioner Controller Front Wiper (1) Relay (WR1) Front Wiper (2) Relay (WR2) GSM (OPT) / GPS (OPT)

T1-2-7

13- Flasher Relay 14- MC (Main Controller) 15- HST Controller

SECTION 1 GENERAL Group 2 Component Layout Front Console 1

2 3

MNDB-01-001

15 16 17 12 18

19 20

22 14

123456-

MNDB-01-002

Air Conditioner Front Vent Hazard Light Switch Work Light Switch Parking Brake Switch Neutral Lever Lock (Forward / Reverse Lever) Steering Wheel

78910-

Monitor Panel Horn Switch Accelerator Pedal Brake / Declutch Pedal (Interlocked) 11- Front / Rear Wiper Switch

21 MNDB-01-003

12- Forward / Reverse Lever / Shift Switch 13- Steering Column Tilt Pedal 14- Tilt, Telescopic Lever 15- Turn Signal Lever / Light Switch / Dimmer Switch 16- Key Switch

T1-2-8

17- 1st Speed Limit Switch 18- Auto Idling Stop Switch (Not Used) 19- Auxiliary 20- Auxiliary 21- Ash Tray 22- Cigar Lighter

SECTION 1 GENERAL Group 2 Component Layout Right Console  Multi-Function Joystick Type

7 8

11 12 13

21 22

123456-

Forward / Reverse Switch (Option) Multi-Function Joystick Lever Auxiliary Auxiliary Auxiliary Control Lever (Option) Control Lever Lock Switch

78910-

17 16

15 MNEC-01-044

MNDB-01-005

Creep Switch (Option) Traction Control Switch Power Mode Switch Forward / Reverse Selector Switch (Option) 11- Fan Reverse Rotation Switch 12- Auxiliary 13- Auxiliary

14- Secondary Steering Operation Check Switch (Option) 15- Exhaust Filter Switch 16- Lift Arm Auto Lever Switch (Upward Set) 17- Lift Arm Auto Lever Switch (Downward Set) 18- Ride Control Switch

T1-2-9

19202122-

Armrest Adjust Handle Armrest Adjustment Auxiliary Horn Switch (Under the Lever)

SECTION 1 GENERAL Group 2 Component Layout

 Fingertip Control Type

3 (2)* 2 (1)*

6 7

20 8 9

1 (3)*

11 12

123456-

* Bucket Control Lever * Lift Arm Control Lever * Auxiliary Control Lever (Option) Forward/Reverse Switch (Option) Control Lever Lock Switch Creep Switch (Option)

14 MNEC-01-042

MNDB-01-004

789-

Traction Control Switch Power Mode Switch Forward/Reverse Selector Switch (Option) 10- Fan Reverse Rotation Switch 11- Auxiliary

12- Quick Coupler Switch (62/67Z7: Option, 67TM7: Standard) 13- Secondary Steering Operation Check Switch (Option) 14- Exhaust Filter Switch 15- Lift Arm Auto Lever Switch (Upward Set)

fNOTE: * The location of control levers may be changed depending on the specification.

T1-2-10

16- Lift Arm Auto Lever Switch (Downward Set) 17- Ride Control Switch 18- Armrest Adjust Handle 19- Armrest Adjustment 20- Horn Switch

SECTION 1 GENERAL Group 2 Component Layout Rear Console

1 4 12 11 10 9

17 16 15 14 13

22 21 20 19 18

27 26 25 24 23

123456789-

Fuse Box B Fuse Box A MPDr. Connector Main Relay Fuel Pump Relay Back Buzzer Relay Starter Cut Relay Head Light Relay (Left) (A-R1) Head Light Relay (Right) (A-R2)

101112131415-

High Beam Relay (A-R3) Bucket Leveler Relay (A-R4) Lift Arm Kickout Relay (A-R5) Work Light (Front) Relay (A-R6) Work Light (Rear) Relay (A-R7) Right Turn Signal Light Relay (A-R8) 16- Horn Relay (A-R9)

17- Secondary Steering Relay (Option)(A-R10) 18- Parking Brake Relay 1 (B-R1) 19- Parking Brake Relay 2 (B-R2) 20- Control Lever Lock Relay (B-R3) 21- Brake Light Relay (B-R4) 22- Load Dump Relay (B-R5) 23- Neutral Relay (B-R6)

T1-2-11

TNED-01-02-009

24- Left Turn Signal Light Relay (B-R7) 25- Front Washer Relay (B-R8) 26- Rear Wiper Relay (B-R9) 27- Rear Washer Relay (B-R10) 28- Relay Box A 29- Relay Box B

SECTION 1 GENERAL Group 2 Component Layout Monitor Panel

39 38

37 12 36 35

14 15

33 32

1234-

Left Turn Signal Light Indicator High Beam Indicator Work Light Indicator Right Turn Signal Light Indicator 5- Exhaust Filter Warning Indicator 6- Exhaust Filter Regeneration Inhibit Indicator 7- Service Indicator 8- Maintenance Indicator 9- Parking Brake Indicator 10- Clearance Light Indicator 11- Control Lever Lock Indicator

16 31 30

29 28 27 26

25 24 23 22 21 20 19 18 17

12- (Unused) 13- Brake Oil Low Pressure Indicator 14- (Unused) 15- Secondary Steering Indicator (Option) 16- Low Steering Oil Pressure Indicator (Option) 17- Seat Belt Indicator 18- Discharge Warning Indicator 19- Fuel Gauge 20- Power Mode Indicator 21- Monitor Display Selection Switch

22- Exhaust Filter Regeneration Inhibit Indicator 23- Monitor Display Selection Switch (Up) 24- Preheat Indicator 25- Monitor Display Selection Switch (Down) 26- Forward/Reverse Selector Switch Indicator (Option) 27- Monitor Display 28- Fan Reverse Rotation Indicator 29- Engine Warning Indicator 30- Overheat Indicator 31- Coolant Temperature Gauge

T1-2-12

MNDB-01-034

32- Engine Oil Low Pressure Indicator 33- Air Filter Restriction Indicator 34- Fuel Filter Restriction Indicator 35- Water Separator Indicator (Option) 36- Hydraulic Oil Level Indicator 37- (Unused) 38- HST Warning Indicator 39- HST Oil Temperature Indicator 40- HST Oil Temperature Gauge

SECTION 1 GENERAL Group 2 Component Layout Engine 6

1 2 3 9

TNDF-01-02-012

TNDF-01-02-013

13 16

TNDF-01-02-014

12345-

VGS Actuator Coolant Temperature Sensor Overheat Switch Glow Plug Intake Throttle

678910-

Common Rail Pressure Sensor Boost Pressure Sensor Boost Temperature Sensor) Crank Revolution Sensor Fuel Temperature Sensor

TNDF-01-02-015

11121314-

T1-2-13

Supply Pump Engine Oil Pressure Sensor Cam Angle Sensor Injector

15- Intake Manifold Temperature Sensor 16- EGR Valve

SECTION 1 GENERAL Group 2 Component Layout

TNDF-05-04-001

9 10

MNDF-07-019

Machine Front Side

123-

MAF Air Cleaner Restriction Switch Atmospheric Pressure Sensor

456-

VGS Controller ECM Fuel Pump

789-

T1-2-14

Fuel Main Filter Fuel Pre-Filter Water Separator (Option)

10- Engine Oil Filter

MNDF-07-005

SECTION 1 GENERAL Group 2 Component Layout Exhaust Filter

TNED-02-03-001

DOC Exhaust Temperature Sensor

CSF Exhaust Temperature Sensor

T1-2-15

Differential Pressure Sensor

SECTION 1 GENERAL Group 2 Component Layout HST Pump, 4-Gear Pump Unit

TNDF-01-02-016

12-

Displacement Angle Control Cylinder Pump Displacement Angle Control Solenoid Valve

345-

Reverse Selection Solenoid Valve Forward Selection Solenoid Valve Shuttle Valve

678910-

T1-2-16

High-Pressure Relief Valve Low-Pressure Relief Valve Cutoff Valve HST Circuit Pressure 1 Sensor HST Circuit Pressure 2 Sensor

TNDF-01-02-017

1112131415-

HST Charging Pump Steering Pump Main Pump Pilot Pump Transmission Charge Pump

SECTION 1 GENERAL Group 2 Component Layout Transmission, HST Motor 1

12-

Clutch Pressure Control Solenoid Valve Transmission

345-

TNDF-01-02-005

Vehicle Speed Sensor 1 Vehicle Speed Sensor 2 HST Motor 2

67-

Motor 2 Displacement Angle Control Solenoid Valve HST Motor 1

Motor 1 Displacement Angle Control Solenoid Valve

Control Valve 9

10 11 12 13

19 9-

Orifice (Exhaust Filter Regeneration Circuit) 10- Pressure Sensor (Implement Pressure) 11- Overload Relief Valve (Bucket: Rod Side)

17 16

12- Make-Up Valve (Lift Arm: Rod Side) 13- Slow Return Valve (Lift Arm: Rod Side) 14- Main Relief Valve 15- Low-Pressure Relief Valve

15 16- Overload Relief Valve (Lift Arm: Bottom side) 17- Overload Relief Valve (Bucket: Bottom Side) 18- Slow Return Valve (Lift Arm: Bottom Side)

T1-2-17

TNDF-01-02-018

19- Overload Relief Valve (Quick Coupler Circuit) (OPT))

SECTION 1 GENERAL Group 2 Component Layout Manifold Valve 1

7 6 4 5

TNDF-01-02-007 123-

Pilot Accumulator (Front) Pilot Reducing Valve Parking Brake Accumulator

Pressure Sensor (Primary Pilot Pressure)

Control Lever Lock Solenoid Valve

67-

Pressure Sensor (Parking Brake ) Parking Brake Solenoid Valve

Brake Charge Valve 9

TNDF-01-02-007 8-

Pressure Sensor (Brake Primary Pressure)

Service Brake Accumulator

T1-2-18

SECTION 1 GENERAL Group 2 Component Layout Fan Valve (for One Direction Rotation)

TNDF-01-02-019

Fan Speed Control Solenoid Valve

Fan Control Valve

Fan Valve (with Fan Reverse Rotation)

2 1

TNDF-01-02-020

12-

Fan Speed Control Solenoid Valve Fan Control Valve

Fan Reverse Rotation Control Solenoid Valve

T1-2-19

SECTION 1 GENERAL Group 2 Component Layout Ride Control Valve

TNDF-01-02-008

12-

Overload Relief Valve Ride Control Solenoid Valve

Ride Control Accumulator

T1-2-20

SECTION 1 GENERAL Group 2 Component Layout Secondary Steering Block (Option)

1 TNDB-01-02-014

Secondary Steering Pump Delivery Pressure Sensor (Option)

Steering Pressure Switch (Option)

Secondary Steering Pump (Option) 3

TNED-01-02-019

Relief Valve

Gear Pump

T1-2-21

Electric Motor

SECTION 1 GENERAL Group 2 Component Layout Solenoid Valve (In Front Chassis) 1

Machine Front

Quick Coupler Pilot Solenoid Valve (Option)

Exhaust Filter Regeneration Control Solenoid Valve

T1-2-22

Coupler Cylinder Selector Solenoid Valve (Option)

TNDF-01-02-024

SECTION 1 GENERAL Group 3 Component Specifications Engine Manufacturer

ISUZU

Model

4HK1

Type

Diesel, 4-Cycle, Water-cooled, Direct Injection Type, Exhaust Turbo Charged Type

Cyl. No.- Bore × Stroke

4-115 mm × 125 mm (4.5 in × 4.92 in)

Piston Displacement

5193 (475 in)

Rated Output

115 kW/2200 min-1 (156 PS/2200 rpm)

Compression Ratio

17.5

Dry Weight

485 (1069 lb)

Firing Order

1-3-4-2

Rotation Direction

Clockwise (Viewed from crank pulley)

T1-3-1

SECTION 1 GENERAL Group 3 Component Specifications Cooling Fan COOLING SYSTEM

Thermostat

Dia. 650 mm (25.6 in), 5 Blades, Hybrid Cracking Temperature at Atmospheric Pressure : 82 ºC (180 ºF) [No.1], 76.5 ºC (169.7 ºF) [No.2] Full Open (Stroke : 8 mm or more) : 95 ºC (203 ºF) [No.1], 90 ºC (194 ºF) [No.2]

Water Pump

Centrifugal Type

Lubrication Pump Type

Gear Pump

Oil Filter

Full-Flow Paper Element Type with Bypass

Oil Cooler

Water Cooled Integral 4-Stage Type

Motor

Magnetic Pinion Shift Reduction Type

Voltage/Output

24 V/5 kW

PREHEAT SYSTEM

Preheating Method

Glow Plug (24V, QOS II Type)

ENGINE STOP SYSTEM

Stop Method

Fuel Shut-Off (Electronic Control)

Type

Regulator Integrated AC Type, Brushless

Voltage/Output

24 V/50 A

Type

Exhaust-Turbocharger Type, Forced Lubrication

Type

Common Rail Type HP3 Type

Governor

Electronic All Speed Control

Injection Nozzle

Electrical Multi-Hole Injector (G2 Type)

LUBRICATION SYSTEM

STARTING SYSTEM

ALTERNATOR SUPERCHARGING SYSTEM FUEL SYSTEM

T1-3-2

SECTION 1 GENERAL Group 3 Component Specifications IMPORTANT: This list shows design specifications, which are not servicing standards.

PERFORMANCE

Fuel Consumption Ratio

226 g/kW/h (166 g/PS·h) (at Full Load : 2200 min-1)

Maximum Output Torque

622 N·m (62 kgf·m, 459 lbf·ft) at1500 min-1

Compression Pressure

3.04 MPa (31 kgf/cm2, 441 psi) at 200 min-1

Valve Clearance (Inlet/Exhaust)

0.4/0.4 mm (0.016/0.016 in) (when cool)

No Load Speed

Low : 800±20 min-1 High : 2450±20 min-1

T1-3-3

SECTION 1 GENERAL Group 3 Component Specifications Engine Performance Curve (4HK1XZWT-01) Test Condition: 1. In conformity with JIS D1005 (Performance Test Method for Diesel Engine Used for Construction Machinery) under standard atmospheric pressure. 2. Equipped with alternator.

N·m

g/kW·h

min-1 (rpm)

kW : Output N·m : Torque

g/kW·h : Fuel Consumption Ratio min-1 (rpm) : Engine Speed

T1-3-4

TNDF-01-03-001

SECTION 1 GENERAL Group 3 Component Specifications Engine Accessories RADIATOR ASSEMBLY

Type

Radiator, Oil Cooler, Intercooler Parallel Type Assembly.

Weight

24.5 kg (54 lb)

Radiator

Inter Cooler

Air-Tight Test Pressure

100 kPa (1.0 kgf/cm , 14 psi)

245 kPa (2.5 kgf/cm2, 35.5 psi)

Cap Opening Pressure

49 kPa (0.5 kgf/cm2, 7 psi)

−

Oil Cooler Air-Tight Test Pressure

1500 kPa (15 kgf/cm2, 218 psi)

Cap Opening Pressure

−

T1-3-5

SECTION 1 GENERAL Group 3 Component Specifications

BATTERY

Type

95D31R

Voltage

12 V

Capacity

64 Ah (5-Hour Rate)

Weight

Approx. 20 kg (44 lb) ×2

T1-3-6

SECTION 1 GENERAL Group 3 Component Specifications Hydraulic Component Type

HST Pump

Maximum Flow Rate (Theoretical Value) Theoretical Displacement High-Pressure Relief Valve Set-Pressure Low-Pressure Relief Valve Set-Pressure Cutoff Valve Set-Pressure

HST Charging Pump

Control System Type Rated Current (Theoretical Value) Theoretical Displacement Type Speed Ratio Function (At the HST Pump Side)

Pump Device

Rated Current (Theoretical Value)

Theoretical Displacement

HST Motor 1

HST Motor 2

Type Function Maximum Flow Rate Control System Type Function Theoretical Displacement Control System

Swash Plate Type (Two-Direction Displacement Angle) Variable Displacement Plunger Pump 0 to 242.9 L/min-1 (64.2 gal/min-1) at 2200 min-1 0 to 110.4 cm3/rev (6.74 in3/rev) 44.5±1.0 MPa (454±10 kgf/cm2, 6454 psi), Differential Pressure 42.0 MPa (428 kgf/cm2, 6092 psi) 2.5±0.1 MPa (25±1 kgf/cm2, 363 psi) 41.2±1.0 MPa (420±10 kgf/cm2), Differential Pressure 38.7 MPa (395 kgf/cm2, 5613 psi) Direct-Drive-Type Proportional Solenoid control Internal Gear Pump 53.9 L/min-1 (14.2 gal/min-1) at 2200 min-1 24.5 cm3/rev (1.5 in3/rev) Fixed Displacement Type Gear Pump Steering Pump: 1, Main Pump: 1, Pilot Pump: 1, Transmission Charge Pump: 1 Steering Pump, Main Pump, Pilot Pump, Transmission Charge Pump Steering Pump: 132 L/min-1 (34.9 gal/min-1) at 2200 min-1 Main Pump: 57.2 L/min-1 (15.1 gal/min-1) at 2200 min-1 Pilot Pump: 44 L/min-1 (11.6 gal/min-1) at 2200 min-1 Transmission Charge Pump 17.6 L/min-1 (4.6 gal/min-1) at 2200 min-1 Steering Pump: 60 cm3/rev (3.7 in3/rev) Main Pump: 26 cm3/rev (1.6 in3/rev) Pilot Pump: 20 cm3/rev (1.2 in3/rev) Transmission Charge Pum: 8 cm3/rev (0.5 in3/rev) Bent-Axis Type Variable Displacement Axial Plunger Motor For Low Speed (Clutch Disconnecting Side) 0 to115.6 cm3/rev (0 to 7 in3/rev) Proportional Solenoid Control Bent-Axis Type Variable Displacement Axial Plunger Motor High Speed (Normally Connected Side) 30 to 115.6 cm3/rev (1.8 to 7 in3/rev) Proportional Solenoid Control

T1-3-7

SECTION 1 GENERAL Group 3 Component Specifications Priority Valve

Relief Set-Pressure Type Main Relief Set-Pressure

Control Valve

Overload Relief Set-Pressure

Front Attachment Pilot Valve (Mono Lever) (Standard)

Low-Pressure Relief Valve Set 0.2 MPa (2.0 kgf/cm2, 29 psi) Pressure Type Joystick Lever, 4-Port (With Electromagnetic Detent) Plunger Stroke

Type Plunger Stroke Type Auxiliary Pilot Valve (OPT) Plunger Stroke Type Auxiliary Pilot Valve (OPT) Plunger Stroke

Front Attachment (NF Lever) Pilot Valve (OPT)

Charging Valve Manifold Valve Service Brake Accumulator Pilot Accumulator

19.6 MPa (200 kgf/cm2, 2843 psi) at 60 L/min (16 gal/min) Pilot Pressure Operated Type (2-Spools) 20.6 MPa (210 kgf/cm2, 2988 psi) at 180 L/min (47.6 gal/min) 27.4 MPa (280 kgf/cm2, 3974 psi) at 35 L/min (9.2 gal/min) (Lift Arm Raise) 22.6 MPa (230 kgf/cm2, 3278 psi) at 35 L/min (9.2 gal/min) (Bucket Tilt) 22.6 MPa (230 kgf/cm2, 3278 psi) at 50 L/min (13 gal/min) (Bucket Dump) 14.9 MPa (152 kgf/cm2, 2161 psi) at 170 L/min (45 gal/min) (Quick Coupler (OPT))

Charging Pressure Function Pilot Reducing Valve SetPressure Capacity Charging Pressure Capacity Charging Pressure

1, 2, 3, 4 Port 10 mm (0.4 in) Finger Type, 4-Port (With Electromagnetic Detent) 1, 2, 3, 4 Port 5.7 mm (0.22 in) Finger Type, 2-Port (Without Detent) 1, 2 Port 4.8 mm (0.19 in) Joystick Lever, 4-Port (Without Detent) 1, 3 Port: 6.5 mm (0.26 in) 2, 4 Port: 8.0 mm (0.32 in) Cut In Pressure : 11.8 MPa (120 kgf/cm2, 1711 psi) Cut Out Pressure : 15.5 MPa (158 kgf/cm2, 2248 psi) For Parking Brake, Control Lever Lock 3.7 MPa (38 kgf/cm2, 537 psi) 1.4 L (1.48 quart) 6.8 MPa (69 kgf/cm2, 986 psi) at 20 °C (68 °F) 0.5 L (0.5 quart) 5.94 MPa (60.6 kgf/cm2, 862 psi) at 20 °C (68 °F)

T1-3-8

SECTION 1 GENERAL Group 3 Component Specifications Parking Brake Accumulator Steering Valve Steering Accumulator Brake Valve

Capacity Charging Pressure Type Overload Relief Set-Pressure Rotor Capacity Capacity Charging Pressure Brake Pressure Type Speed Ratio

Transmission

Standard Axle (Front, Rear)

Standard Propeller Shaft

Clutch Pressure Parking Brake Release Pressure Model Brake Type Brake Pressure Final Reduction Gear Ratio Type Dimension between Pins

0.5 L (0.5 quart) 1.57 MPa (16 kgf/cm2, 228 psi) at 20 °C (68 °F) Orbitrol Type 24.6 MPa (251 kgf/cm2, 3568 psi) at 1 L/min (1 quart/min) 369 cm3/rev (22.5 in3/rev) 0.2 L (0.2 quart) 2 MPa (20 kgf/cm2, 290 psi) 3.63 MPa (37 kgf/cm2, 526 psi) Counter Shaft Type Low Speed (HST Motor 2 Side): 3.649 Fast Speed (HST Motor 1 Side): 1.500 1.8 to 2.0 MPa (18 to 20 kgf/cm2, 261 to 290 psi) 2.7 MPa (28 kgf/cm2, 392 psi) Two Stage Transmission Wet-Type Spring Set Hydraulic Released Single Brake 3.63 MPa (37 kgf/cm2, 526 psi) 21.938 Cruciform Joint Type Front : 1615.7 mm (5’3.6”) Rear : 245 mm (9’6”)

T1-3-9

SECTION 1 GENERAL Group 3 Component Specifications Fan Motor

Theoretical Displacement Function Solenoid Valve (Fan Valve) Relief Set-Pressure

Ride Control Valve

Ride Control Accumulator

Solenoid Valve (For Exhaust Filter Regeneration Control) Solenoid Valve (For Quick Coupler Pilot) Solenoid Valve (For Coupler Cylinder Selector)

Type

Pilot Pressure Operated Type

Overload Relief Set-Pressure

28.4 MPa (290 kgf/cm2, 4119 psi) at 50 L/min (13 gal/min)

Charge-Cut Valve

8.5 MPa (87 kgf/cm2, 1233 psi)

Capacity

2.5 L (0.66 gal)

Charging Pressure

2.0 MPa (20 kgf/cm2, 290 psi)

Function Rated Pressure Power Voltage Function Rated Pressure Power Voltage Function Rated Pressure Power Voltage

Solenoid Valve (For Exhaust Filter Regeneration Control) 3.7 MPa (38 kgf/cm2, 537 psi) DC 24V Quick Coupler Circuit (OPT) 4.9 MPa (50 kgf/cm2, 711 psi) DC24V Quick Coupler Circuit (OPT) 21.0 Mpa (214 kgf/cm2, 3046 psi) DC 24V

Secondary Steering Block Function  67TM7 Bucket Regenerative Valve Bucket Regenerative Selector Valve

16.4 cm3/rev (1 in3/rev) Fan Motor Speed Control, Fan Motor Reverse Rotation Control 13.7 MPa (140 kgf/cm2, 1987 psi) at 10 L/min (2.6 gal/min)

Function Maximum Flow Rate Rated Pressure Function Control Pressure (Pilot Pressure)

Secondary Steering Circuit (OPT)

For increasing bucket dump speed 320 L (84.5 gal)/min-1@2200 min-1 27.4 Mpa (279 kgf/cm2, 3973 psi) Main Circuit/bucket dump circuit (parallel link front attachment) 3.7 Mpa (37.7 kgf/cm2, 536.5 psi)

T1-3-10

SECTION 1 GENERAL Group 3 Component Specifications  62Z7 CYLINDER

Lift Arm (Right, Left) Bucket

Steering

Quick Coupler (OPT)

Rod Diameter

65 mm (2.6”)

85 mm (3.3”)

40 mm (1.5”)

25 mm (1.0”)

Cylinder Bore

125 mm (4.9”)

150 mm (5.9”)

65 mm (2.6”)

45 mm (1.8”)

Stroke

620 mm (25”)

445 mm (18”)

419 mm (16”)

200 mm (7.9”)

Fully Retracted Length 1114 mm (3’8”)

995 mm (38”)

728 mm (29”)

390 mm (15”)

Plating Thickness

30 μm (1.18 μm) 30 μm (1.18 μm)

30 μm (1.18 μm)

30 to 40 mm (1.2 to 1.6”)

 67Z7 CYLINDER

Lift Arm (Right, Left) Bucket

Steering

Quick Coupler (OPT)

Rod Diameter

65 mm (2.6”)

85 mm (3.3”)

40 mm (1.5”)

25 mm (1.0”)

Cylinder Bore

125 mm (4.9”)

150 mm (5.9”)

65 mm (2.6”)

45 mm (1.8”)

Stroke

760 mm (30”)

495 mm (1’8”)

419 mm (1’5”)

200 mm (7.9”)

Fully Retracted Length 1254 mm (4’1”)

960 mm (38”)

728 mm (2’5”)

390 mm (1’3”)

Plating Thickness

30 μm (1.18 μm) 30 μm (1.18 μm)

30 μm (1.18 μm)

30 to 40 mm (1.2 to 1.6”)

 67TM7 CYLINDER

FILTER

Lift Arm (Right, Left) Bucket (Right, Left)

Steering

Quick Coupler

Rod Diameter

65 mm (2.6”)

60 mm (2.4”)

40 mm (1.5”)

25 mm (1.0”)

Cylinder Bore

125 mm (4.9”)

110 mm (4.3”)

65 mm (2.6”)

45 mm (1.8”)

Stroke

760 mm (30”)

1005 mm (3’3.6”)

419 mm (1’5”)

200 mm (7.9”)

Fully Retracted Length 1254 mm (4’1”)

1580 mm (5’2.2”)

728 mm (2’5”)

390 mm (1’3”)

Plating Thickness

30 μm (1.18 μm) 30 μm (1.18 μm) 30 to 40 mm (1.2 to 1.6”)

30 μm (1.18 μm)

Full-Flow Filter (Filtration)

β10: 2.0 or more (filters 50% or more particles 10 μm in diameter)

Suction Filter (Filtration)

177 μm (80 mesh)

Pilot Filter, Charge Oil Filter (Brake, HST, Transmission) (Filtration)

β10: 1.4 or more (filters 30% or more particles 10 μm in diameter)

T1-3-11

SECTION 1 GENERAL Group 3 Component Specifications Electrical Component ENGINE OIL PRESSURE SENSOR

Operating Pressure

48 kPa (0.5 kgf/cm2, 7.0 psi)

OVER HEAT SWITCH

Operating Temperature

105±2 °C (221±2 °F)

COOLANT TEMPERATURE Operating Temperature SENSOR

-10 to 110 °C (14 to 230 °F)

FUEL LEVEL SENSOR

Resistance Value

Empty : 90+100 Ω, Full : 100-4 Ω

HYDRAULIC OIL TEMPERATURE SENSOR

Operating Temperature

-30 to 120 °C (-22 to 248 °F)

BATTERY RELAY

Voltage/Current

24 V/100 A

STARTER RELAY 2

Voltage

24 V

GLOW RELAY

Voltage

24 V

T1-3-12

SECTION 1 GENERAL Group 3 Component Specifications AIR FILTER RESTRICTION SWITCH

Operating Pressure

6.2±0.6 kPa (0.9±0.09 PSI)

HORN

Voltage/Current

24 V·1.5±0.7 A

Sound Pressure

113±5 dB (A) at 2 m (6’7”)

Work Light

Halogen 24 V, 70 W (51.6 PS)

Cab Light

24 V, 10 W (7.4 PS)

Head Light

Halogen 24 V, 75/70 W (55.3/51.6 PS)

Turn Signal Light

24 V, 25 W (18.4 PS) (Front), 21W (15.5 PS) (Rear)

Clearance Light

24 V, 4 W (3.0 PS) (EU)/24V, 5W (3.7 PS)

License Light

24 V, 10 W (7.4 PS) × 2 pcs

Tail Light

24 V, 5 W (3.7 PS) (EU)

Brake Light

24 V, 21 W (15.5 PS)

Refrigerant

134 a

Cooling Ability

4.65 kW (6.2 HP) or More

Cool Air Volume

550 m3/h (719 yd3/h) or More

Heating Ability

5.81 kW (7.8 HP) or More

Warm Air Volume

400 m3/h (523 yd3/h) or More

Temperature Adjusting System

Electronic Type

Refrigerant Quantity

900±50 g (2±0.1 lb)

Compressor Oil Quantity

160 cm3 (160 in3)

Type

Electric Motor Operated Type

Theoretical Displacement

7.0 cm3/rev (0.43 in3/rev)

Maximum Flow

15 L/min (3.96 gal/min) at 10.0 MPa (102 kgf/cm2, 1450 psi)

Voltage

24 V, 2.4 kW (3.2 HP)

ILLUMINATION

AIR CONDITIONER

SECONDARY STEERING PUMP UNIT ELECTRIC MOTOR

T1-3-13

SECTION 1 GENERAL Group 3 Component Specifications (Blank)

T1-3-14

SECTION 2

SYSTEM CONTENTS Group 1 Controller

Outline..................................................................................... T2-1-1 CAN Circuit............................................................................. T2-1-2

Group 2 Control System

Outline..................................................................................... T2-2-1 Engine Control...................................................................... T2-2-4 Engine Protection Control........................................... T2-2-6 Accelerator Pedal Control............................................ T2-2-8 Auto-Warm Up Control..............................................T2-2-10 Forward/Reverse Idle Speed Limiter.....................T2-2-12 Load-free Engine High Idle Limiter........................T2-2-14 Speed Limit Control with Power Mode OFF.......T2-2-16 Fan Reverse Rotation Idle Speed Limiter.............T2-2-18 HST Pump/Motor Control, Transmission Control...T2-2-21 Pump Power Control...................................................T2-2-22 Matching Control.........................................................T2-2-24 Motor Displacement Angle Control......................T2-2-26 Inching Control.............................................................T2-2-28 Forward/Reverse Selection Control.......................T2-2-30 Reverse-Acceleration Prevention Control at Forward/Reverse Selection..................................T2-2-32 Forward/Reverse Lever Priority Control (Option).......................................................................T2-2-34 Speed Shift Control......................................................T2-2-36 Clutch Control................................................................T2-2-38 Speed Limit Control.....................................................T2-2-40 Engine Protection Control.........................................T2-2-42 Overrun Prevention Control.....................................T2-2-44 Overheat Prevention Control...................................T2-2-46 Safety Park Control (On Slope)................................T2-2-48 Energy Saving Control................................................T2-2-50 HST Alarm Control........................................................T2-2-52 Fan Control, Valve Control..............................................T2-2-55 Fan Speed Control........................................................T2-2-56 Fan Reverse Rotation Control..................................T2-2-58 Ride Control....................................................................T2-2-60 Exhaust Filter Manual Regeneration Control.....T2-2-62 Exhaust Filter Auto Regeneration Control...........T2-2-64 Other Controls....................................................................T2-2-67 Low Brake Oil Pressure Indicator Control............T2-2-68 Low Steering Oil Pressure Indicator Control (Option).......................................................................T2-2-70

Lift Arm Auto Leveler Height Kickout Control (Option).......................................................................T2-2-72 Lift Arm Auto Leveler Lower Kickout Control (Option).......................................................................T2-2-74 Auto Idling Stop Control (Not used)......................T2-2-76 Secondary Steering Control (Option)...................T2-2-78 Control by Electric and Hydraulic Combined Circuit............................................................................T2-2-81 Bucket Auto Leveler Control.....................................T2-2-82 Lift Arm Float Control.................................................T2-2-84 Lift Arm Kickout Control............................................T2-2-86

Group 3 ECM System

Outline..................................................................................... T2-3-1 Fuel Injection Control......................................................... T2-3-2 Fuel Injection Volume Control................................... T2-3-4 Fuel Injection Pressure Control................................. T2-3-6 Fuel Injection Timing Control.................................... T2-3-8 Fuel Injection Rate Control......................................... T2-3-8 Operation of Fuel Injection......................................... T2-3-8 Fuel Injection Volume Correction Control................T2-3-10 EGR Control..........................................................................T2-3-12 Preheating Control............................................................T2-3-14 Alarm Control......................................................................T2-3-15 Exhaust Filter.......................................................................T2-3-16 Exhaust Filter Operation............................................T2-3-17 Exhaust Filter Regenerative Control............................T2-3-18 Variable Turbocharger Control......................................T2-3-20

Group 4 Hydraulic System

Outline..................................................................................... T2-4-1 Main Circuit............................................................................ T2-4-2 Neutral Circuit.................................................................. T2-4-4 Bucket Tilt Circuit (Parallel Link Front Attachment)................................................................. T2-4-6 Bucket Dump Circuit (Parallel Link Front Attachment)................................................................. T2-4-8 Combined Operation Circuit....................................T2-4-10 Steering Circuit...................................................................T2-4-12 Priority Valve Circuit....................................................T2-4-14 Steering Circuit..............................................................T2-4-16 Steering Stop Circuit...................................................T2-4-18 Secondary Steering Circuit (Option)...........................T2-4-20

62Z7/67Z7/67TM7 (OCE)

Pilot Circuit...........................................................................T2-4-22 Charging Circuit............................................................T2-4-24 Service Brake Circuit....................................................T2-4-28 Parking Brake Circuit...................................................T2-4-30 Front Attachment Operation Circuit.....................T2-4-32 Ride Control Circuit......................................................T2-4-34 Exhaust Filter Regeneration Control Circuit.......T2-4-38 Quick Coupler Circuit (Option)................................T2-4-40 HST Circuit............................................................................T2-4-44 Charge Circuit................................................................T2-4-46 Neutral Circuit................................................................T2-4-46 Forward Circuit..............................................................T2-4-48 Reverse Circuit...............................................................T2-4-48 Inching Circuit...............................................................T2-4-50 Transmission Circuit..........................................................T2-4-52 Clutch Connecting Circuit.........................................T2-4-54 Clutch Disconnecting Circuit...................................T2-4-56 Transmission Lubrication Circuit............................T2-4-56 Fan Circuit.............................................................................T2-4-58 Fan Normal Rotation Control Circuit.....................T2-4-60 Fan Normal Rotation Control Circuit.....................T2-4-62 Fan Reverse Rotation Control Circuit....................T2-4-62

Work Light Circuit..............................................................T2-5-52 Wiper Circuit........................................................................T2-5-54 Front Wiper Circuit.......................................................T2-5-54 Rear Wiper Circuit.........................................................T2-5-56 Washer Circuit................................................................T2-5-58 Cab Light Circuit.................................................................T2-5-60

Group 5 Electrical System

Outline..................................................................................... T2-5-1 Main Circuit............................................................................ T2-5-2 Electric Power Circuit (Key Switch: OFF)...................... T2-5-4 Light Bulb Check Circuit (Key Switch: ON).................. T2-5-6 CAN Circuit............................................................................. T2-5-8 Accessory Circuit (Key Switch: ACC)............................T2-5-10 Starting Circuit (Key Switch: START)............................T2-5-12 Starter Relay 1 Operation..........................................T2-5-14 Neutral Engine Start Circuit............................................T2-5-16 Charging Circuit (Key Switch: ON)...............................T2-5-18 Alternator Operation...................................................T2-5-20 Regulator Operation...................................................T2-5-21 Surge Voltage Prevention Circuit.................................T2-5-22 Engine Stop Circuit............................................................T2-5-24 Auto Idling Stop Circuit (Not Used).............................T2-5-26 Steering Column Monitor Circuit.................................T2-5-29 Head Light Circuit..............................................................T2-5-30 Clearance Light, License Light, Tail Light Circuit............................................................T2-5-30 Head Light Circuit........................................................T2-5-32 High Beam Circuit........................................................T2-5-34 Hazard Light Circuit (Key Switch: OFF).......................T2-5-36 Turn Signal Light Circuit:.................................................T2-5-38 Horn Circuit (Key Switch: OFF)......................................T2-5-40 Reverse Buzzer Circuit......................................................T2-5-42 Brake Light Circuit.............................................................T2-5-44 Parking Brake Circuit.........................................................T2-5-46 Parking Brake: Released.............................................T2-5-46 Parking Brake: Applied...............................................T2-5-48 Accessory Circuit................................................................T2-5-51

62Z7/67Z7/67TM7 (OCE)

SECTION 2 SYSTEM Group 1 Controller Outline The following controllers are provided in this machine in order to control functions. Each controller excluding the communication controller communicates by using the CAN circuit and sends or receives the required signal. Controller

Control

MC (Main Controller) HST (Hydrostatic Transmission) Controller ECM (Engine Control Module) VGS (Variable Geometry System) Controller Information Controller Column Display Controller Air Conditioner Controller Communication Controller

Controls the engine speed, pump, and valves. Controls the transmission, HST pump and HST motors 1, 2.

Comment on Control T2-2 T2-2

Controls the engine. Controls the engine turbocharger.

T2-3 T2-3

Accumulates the operating information and alarms. Controls the wiper and buzzer. Displays the gauge and indicator. Controls the air conditioner. Sends the mails and operating information.

T5-2 T2-5 T2-5, T5-7 T5-3

fNOTE: Refer to the corresponding group for details of each controller control.

T2-1-1

SECTION 2 SYSTEM Group 1 Controller CAN Circuit CAN (Controller Area Network) is ISO Standards of the serial communication protocol. Three networks (CAN bus (4)), CAN 1 (1), CAN 2 (5) and CAN 3 (18) are equipped for this machine. CAN 1 (1) is used for the engine control. CAN 2 (5) is used for the accessories. CAN bus (4) consists of two harnesses, CAN-H (High) (2) and CAN-L (Low) (3). Each controller judges the CAN bus (4) level due to potential difference between CAN-H (High) (2) and CAN-L (Low) (3). Each controller arranges the CAN bus (4) level and sends the signal and data to other controllers. In addition, terminating resistors (120 Ω) (17) are installed to both ends of CAN bus (4).

T2-1-2

SECTION 2 SYSTEM Group 1 Controller 2 1 3

2 5 3

TDAA-02-05-001

18 9

10 11

12 5

17 17 19 13

TNDB-02-01-001

12345-

CAN 1 CAN-H (High) CAN-L (Low) CAN Bus CAN 2

678-

VGS Controller (Variable Geometry System) ECM (Engine Controller) MC (Main Controller)

HST (Hydrostatic Transmission) Controller 10- Communication Controller 11- Information Controller 12- MPDr.

T2-1-3

1314171819-

Air Conditioner Controller Column Display Controller Terminating Resistor (120 Ω) CAN 3 Rear View Monitor (Option)

SECTION 2 SYSTEM Group 1 Controller (Blank)

T2-1-4

SECTION 2 SYSTEM Group 2 Control System Outline Main Controller (MC) is used in order to control the machine operations. The signals from the accelerator pedal sensor, various sensors, switches, and Hydrostatic Transmission (HST) controller are sent to MC and processed in the logic circuit. MC sends the signals equivalent to the target engine speed to Engine Control Module (ECM) by using Controller Area Network (CAN) communication in order to control the engine. (Refer to SYSTEM / ECM System.) MC activates various solenoid valves in order to control the fan valve and the exhaust filter regeneration. The HST controller is used in order to control the machine travel operations. The signals from the brake angle sensor, forward/reverse lever, shift switch, various sensors, switches, and MC are sent to the HST controller and processed in the logic circuit. The HST controller activates the pump displacement angle control solenoid valve, forward/reverse control solenoid valve, motor 1 displacement angle control solenoid valve, motor 2 displacement angle control solenoid valve, and clutch pressure control solenoid valve to control the HST pump, HST motor 1, HST motor 2, and transmission.

T2-2-1

SECTION 2 SYSTEM Group 2 Control System Engine Control, HST Pump/Motor Control, Transmission Control < Input Signal > Accelerator Pedal Sensor HST Oil Temperature Sensor 1st Speed Limit Switch Key Switch Power Mode Switch Traction Control Switch Fan Reversing Switch Creep Switch (Option)

       

HST Circuit Pressure 1 Sensor HST Circuit Pressure 2 Sensor Machine Speed 1 Sensor Machine Speed 2 Sensor Brake Angle Sensor Pressure Sensor (Front Attachment Pressure) Forward/Reverse Lever Forward/Reverse Switch (Option) Forward/Reverse Selector Switch (Option) Shift Switch

     

HST Controller

Crank Revolution Sensor Cam Angle Sensor

 

Coolant Temperature Sensor



Monitor Maintenance Pro Dr. (MPDr.)

 

Information Controller

Pressure Sensor (Parking Brake)



Column Display Controller

    ECM

T2-2-2

< Output Signal > Engine Control  Engine Protection Control  Accelerator Pedal Control  Auto-Warm Up Control  Forward/Reverse Idle Speed Limiter  Load-Free Engine High Idle Limiter  Speed Limit Control with Power Mode OFF  Fan Reverse Rotation Idle Speed Limiter HST Pump/Motor, Transmission Control  Pump Power Control  Matching Control  Motor Displacement Angle Control  Inching Control  Reverse-Acceleration Prevention Control at Forward/Reverse Selection  Forward/Reverse Selection Control  Forward/Reverse Lever Priority Control (Option)    

Manual Speed Shift Control Clutch Control Speed Limit Control Engine Protection Control

    

Overrun Prevention Control Overheat Prevention Control Safety Park Control (On Slope) Energy Saving Control HST Alarm Control

 Controller Area Network (CAN)

SECTION 2 SYSTEM Group 2 Control System Fan Control, Valve Control, Other Controls < Input Signal > Accelerator Pedal Sensor Pressure Sensor (Fan Circuit Pressure) Pressure Sensor (Brake Primary Pressure) Pressure Sensor (Refrigerant Pressure) Pressure Sensor (Primary Pilot Pressure) HST Oil Temperature Sensor Lift Arm Angle Sensor Secondary Steering Pump Delivery Pressure Sensor (Option) Steering Pressure Switch (Option) Key Switch Exhaust Filter Regeneration Switch Fan Reversing Switch Ride Control Switch Auto Idling-Stop Switch (Not used) Lift Arm Auto Leveler (Raise) Switch (Option) Lift Arm Auto Leveler (Lower) Switch (Option) Secondary Steering Operation Check Switch (Option)



    

< Output Signal > Fan Control, Valve Control  Fan Speed Control  Fan Reverse Rotation Control  Ride Control  Exhaust Filter Manual Regeneration Control  Exhaust Filter Auto Regeneration Control

 



Other Control  Low Brake Oil Pressure Indicator Control  Low Steering Oil Pressure Indicator Control (Option)



 

Lift Arm Auto Leveler Height Kickout Control  Lift Arm Auto Leveler Lower Kickout Control  Auto Idling-Stop Control (Not used)  Secondary Steering Control (Option)

    

Control by Electric and Hydraulic Combined Circuit HST Controller

Machine Speed 1 Sensor Machine Speed 2 Sensor Pressure Sensor (Front Attachment Pressure)



Crank Revolution Sensor Cam Angle Sensor Coolant Temperature Sensor Boost Temperature Sensor



Monitor Maintenance Pro Dr. (MPDr.)

 Information 

Controller

Pressure Sensor (Parking Brake)



Column Display Controller

 

Bucket Auto Leveler Control Lift Arm Float Control  Lift Arm Kickout Control



ECM

  



Outdoor Ambient Temperature Sensor



Air Conditioner Controller

T2-2-3

CAN

SECTION 2 SYSTEM Group 2 Control System Engine Control The engine control consists of the followings.  Engine Protection Control  Accelerator Pedal Control  Auto-Warm Up Control  Forward/Reverse Idle Speed Limiter  Load-Free Engine High Idle Limiter  Speed Limit Control with Power Mode OFF  Fan Reverse Rotation Idle Speed Limiter

T2-2-4

SECTION 2 SYSTEM Group 2 Control System Engine Control, HST Pump/Motor Control, Transmission Control System Layout 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-001

Forward Position

Reverse Position

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Main Controller (MC) Column Display Controller Monitor Information Controller MPDr. Air Conditioner Controller HST Controller HST Motor 2 HST Motor 1 Transmission Parking Brake CAN Communication HST Pump/4-Gear Pump Unit Engine ECM

16- Brake Pedal 17- Brake Angle Sensor 18- Pressure Sensor (Front Attachment Pressure) 19- Shift Switch 20- Forward/Reverse Lever 21- Forward/Reverse Switch (Option) 22- Forward/Reverse Selector Switch (Option) 23- Machine Speed 1 Sensor 24- Machine Speed 2 Sensor 25- Motor 2 Displacement Angle Control Solenoid Valve

Neutral Position

26- Motor 1 Displacement Angle Control Solenoid Valve 27- Clutch Pressure Control Solenoid Valve 28- Pressure Sensor (Parking Brake) 29- Parking Brake Switch 30- Parking Brake Solenoid Valve 31- Forward/Reverse Control Solenoid Valve 32- Pump Displacement Angle Control Solenoid Valve 33- HST Circuit Pressure 1 Sensor 34- HST Circuit Pressure 2 Sensor 35- Crank Speed Sensor

T2-2-5

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Cam Angle Sensor Coolant Temperature Sensor Boost Temperature Sensor Accelerator Pedal Accelerator Pedal Sensor HST Oil Temperature Sensor 1st Speed Limit Switch Key Switch Power Mode Switch Traction Control Switch Fan Reversing Switch Creep Switch (Option)

SECTION 2 SYSTEM Group 2 Control System Engine Protection Control Purpose: Immediately after the engine starts, the increase of engine speed is limited and engine oil circulation is facilitated. This prevents the engine turbocharger from breakage.

A E

Operation: 1. When starting the engine, Main Controller (MC) (1) receives the signals from coolant temperature sensor (37) and Hydrostatic Transmission (HST) oil temperature sensor (41), and responds by sending a signal corresponding to the target RPM's to Engine Control Module (ECM) (15) via Controller Area Network (CAN) communication (12) based on these temperature sensor signals. 2. ECM (15) keeps the engine at low idle speed 800 min-1 (RPM) (F) for 3~6 seconds. 3. MC (15) automatically deactivates the engine protection control in a fixed period of time after the engine start.

F C

B TNED-02-02-065

A - Engine Speed B - Accelerator Pedal Position C - Accelerator Pedal Position: Not applied D - Accelerator Pedal Position: Fully applied

4. At this point, ECM (15) slowly returns the engine speed (RPM or min-1) controlled by accelerator pedal (39) or other.

fNOTE: Engine protection control is given a highest

priority over all other controls. Therefore, while it is being activated, the engine speed does not change by applying accelerator pedal (39) or any other operation.

T2-2-6

EF-

High Idle Speed (2450 min-1 (RPM)) Low Idle Speed (800 min-1 (RPM))

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-021

Forward Position

Reverse Position

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Neutral Position

T2-2-7

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SECTION 2 SYSTEM Group 2 Control System Accelerator Pedal Control Purpose: The accelerator pedal control controls the engine speed according to the accelerator pedal (39) angle.

A E

Operation: 1. Main Controller (MC) (1) receives the signals from the accelerator pedal and responds by sending a signal to Engine Control Module (ECM) (15) via Controller Area Network (CAN) communication (12) based on the accelerator pedal angle.

F G C

2. ECM (15) controls the engine speed by responding to CAN signal (12).

B TNED-02-02-002

3. When the signal from accelerator pedal sensor (40) is out of acceptable range, MC (1) sends a backup signals to ECM (15).

A - Engine Speed B - Accelerator Pedal Position C - Accelerator Pedal Position: Not applied D - Accelerator Pedal Position: Fully applied

4. ECM (15) limits the engine speed to specified value 1300 min-1 (RPM) (F). 5. When accelerator pedal sensor (40) fails and has to be replaced, the engine RPM control will be returned to the accelerator pedal by doing the following. 1) Turn the key switch (43) OFF. 2) Be sure the key switch (43) is OFF for at least 10 seconds. 3) Turn the key switch (43) ON. The RPM's should now be controlled by the accelerator pedal sensor. 6. After the above procedure 5 has been done, ECM (15) will recognize the signal coming from the MC (3) as provided from accelerator pedal sensor (40), according to the angle of the pedal, and the engine RPM's will be controlled by accelerator pedal (39).

T2-2-8

E-

High Idle Speed (2450 min-1 (RPM)) F - Specified Value (1300 min-1 (RPM)) G - Low Idle Speed (800 min-1 (RPM))

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-022

Forward Position

Reverse Position

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Neutral Position

T2-2-9

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SECTION 2 SYSTEM Group 2 Control System Auto-Warm Up Control A

Purpose: The auto-warm up control warms up the engine as shown below.

Operation: 1. Main Controller (MC) (1) receives the signal from Hydrostatic Transmission (HST) oil temperature sensor (41).

D E

2. When key switch (43) is in the ON or START position and HST oil temperature is below 0 °C (32 °F), MC (1) sends the target engine RPM signal to Engine Control Module (ECM) (15) by using Controller Area Network (CAN) communication (12). 3. ECM (15) increases the engine speed from 800 min-1 (RPM's) (E) to 1000 min-1 (RPM's) (D). This action permits quicker warm-up of the engine. 4. When any of the items under the topic below of "Deactivation Conditions" exists, MC (1) deactivates the auto-warm up control.

B TNED-02-02-004

A - Engine Speed B - Target Engine Speed C - High Idle Speed (2450 min-1 (RPM))

5. At this point, ECM (15) returns the engine speed (min-1 or RPM) control back to the accelerator pedal (39) position. Deactivation Conditions:  In 10 minutes after key switch (43) is set to the ON or START position  HST Oil Temperature: 30 °C (85 °F) or more  Coolant Temperature: 40 °C (105 °F) or more  Parking Brake: Release

fNOTE: The engine low idle speed can be adjusted by Maintenance Pro Dr. (MPDr.) (5).

IMPORTANT: When adjusting the auto-idle speed, deactivate the auto-warm up control by using MPDr. (5). Make this adjustment only after waiting for 10 minutes to permit the systems to warm up.

T2-2-10

D - Auto- Warm Up Speed (1000 min-1 (RPM)) E - Low Idle Speed (800 min-1 (RPM))

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-023

Forward Position

Reverse Position

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Neutral Position

T2-2-11

363738394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Forward/Reverse Idle Speed Limiter Purpose: The forward/reverse idle speed limiter increases the engine speed from the low idle speed to the increased idle speed to prevent engine stall when the transmission is engaged (this takes place when the forward/reverse lever is shifted or the steering is operated). In addition, the forward/reverse idle speed limiter reduces the engine speed in order to reduce fuel consumption and noise level when the forward/reverse lever is in the neutral position.

A E

F G B

Operation: 1. Hydrostatic Transmission (HST) controller (7) receives the signal from forward/reverse lever (20) and sends an output signal to Main Controller (MC) (1) via Controller Area Network (CAN) communication (12).

D TNED-02-02-004

2. When the item under the topic below of "Conditions" exists, MC (1) sends a target RPM (min1 ) signal to Engine Control Module (ECM) (15) via CAN communication (12).

A - Engine Speed B - Accelerator Pedal Position C - Accelerator Pedal Position: Not applied D - Accelerator Pedal Position: Fully applied

3. ECM (15) increases the idle speed to 900 min-1 (RPM) (F) from low idle speed (G) when the engine speed is below 900 min-1 (RPM). 4. MC (1) deactivates the forward/reverse idle speed limiter when forward/reverse lever (20) is set to neutral position (c). 5. At this point, ECM (15) returns the engine speed (Min-1 or RPM) control back to the accelerator pedal (39) position. Conditions: Forward/Reverse Lever (20) or Forward/Reverse Switch (21) (Option): Forward Position (a) or Reverse Position (b)

T2-2-12

E-

High Idle Speed (2450 min-1 (RPM)) F - Forward/Reverse Idle Speed Speed (900 min-1 (RPM)) G - Low Idle Speed (800 min-1 (RPM))

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-024

Forward Position

Reverse Position

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Neutral Position

T2-2-13

363738394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Load-free Engine High Idle Limiter A

Purpose: The load-free engine high idle limiter limits high idle speed when the hydraulic oil pump pressure is below a pressure that permits the system to operate efficiently, and the result is better fuel economy.

E F G

Operation: 1. Hydrostatic Transmission (HST) controller (7) receives a signal from pressure sensor (front attachment pressure) (18) and sends the signal to Main Controller (MC) (1) via Controller Area Network (CAN) communication (12). 2. When all of the items under the topic below of "Conditions" exist, MC (1) sends a target RPM (min-1) signal to Engine Control Module (ECM) (15) via CAN communication (12). 3. ECM (15) reduces and limits the engine RPM's as shown below under "Specified Value" - either (F) or (G) via CAN communication (12).  Specified Value (2350 min-1) (F): Front attachment pressure is 3 MPa (31 kgf/cm2, 435 psi) to 7 MPa (71 kgf/cm2, 1015 psi) .  Specified Value (1850 min-1) (G): Front attachment pressure is 3 MPa (31 kgf/cm2, 435 psi) or less.

H C

B TNED-02-02-011

A - Engine Speed B - Accelerator Pedal Position C - Accelerator Pedal Position: Not applied D - Accelerator Pedal Position: Fully applied E - High Idle Speed (2450 min-1 (RPM))

F-

Specified Value (2350 min-1 (RPM)) G - Specified Value (1850 min-1 (RPM)) H - Low Idle Speed (800 min-1 (RPM))

fNOTE: When moving the lift arm with the bucket

4. When any of the item listed under "Deactivation Conditions" exist, ECM (15) returns the engine speed (min-1 or RPM) control back to the accelerator pedal (39) position. Conditions:  Front Attachment Pressure: Below specified value (Reference: Less than 7 MPa (71 kgf/cm2, 1015 psi))  Forward/Reverse Lever (20) or Forward/Reverse Switch (21) (Option): Neutral Position (c)  (Machine Speed: 3 km/h (1.8 mph) or less) Deactivation Conditions:  Front Attachment Pressure: High Pressure (Reference: 7 MPa (71 kgf/cm2, 1015 psi) or more)  Forward/Reverse Lever (20) or Forward/Reverse Switch (21) (Option): Forward Position (a) or Reverse Position (b)  (Machine Speed: 3 km/h (1.8 mph) or more)

T2-2-14

empty, front attachment pressure will be in mid-range pressures between 3 MPa (31 kgf/cm2, 435 psi) and 7 MPa (71 kgf/cm2, 1015 psi) ).

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-025

Forward Position

Reverse Position

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Neutral Position

T2-2-15

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SECTION 2 SYSTEM Group 2 Control System Speed Limit Control with Power Mode OFF Purpose: The speed limit control with power mode OFF limits the high idle speed with the power mode set OFF. Therefore, fuel consumption is reduced.

A E F

Operation: 1. Main Controller (MC) (1) receives the signal from power mode switch (44). 2. Engine Control Module (ECM) (15) sends the actual engine speed data from engine (14) to MC (1) via Controller Area Network (CAN) communication (12).

3. MC (1) sends a target RPM (min ) signal to ECM (15) by using CAN communication (12) with the power mode set OFF. -1

4. ECM (15) reduces and limits the engine speed to the specified value (2200 min-1) (F) when the engine speed is above the limited engine speed with power mode OFF. 5. When any of the items under the topic below of "Conditions" exists, MC (1) forcibly turns off the power mode and activates the speed limit control with power mode OFF.

B TNED-02-02-015

A - Engine Speed B - Accelerator Pedal Position C - Accelerator Pedal Position: Not applied D - Accelerator Pedal Position: Fully applied

 When the selected range is second or first, the engine speed is limited to a given value. The engine speed value is relative to the propulsion load.  When third range is selected, the engine speed is limited from higher revolutions to 2180 min-1 (RPM's). Conditions: Speed Shift: 3rd or 4th speed (Forward/Reverse)  Coolant Temperature: 93 °C (199 °F) or more  HST Oil Temperature: 93 °C (199 °F) or more  Machine Speed: 30 km/h (18.6 mph) or more Speed Shift: 1st or 2nd speed (Forward/Reverse)  Coolant Temperature: 98 °C (208 °F) or more

T2-2-16

E-

High Idle Speed (2450 min-1 (RPM)) F - Specified Value (2200 min-1 (RPM)) G - Low Idle Speed (800 min-1 (RPM))

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-026

Forward Position

Reverse Position

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Neutral Position

T2-2-17

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SECTION 2 SYSTEM Group 2 Control System Fan Reverse Rotation Idle Speed Limiter Purpose: The fan reverse rotation idle speed limiter increases the low idle speed of the engine and prevents the fan reverse rotation from stopping when returning the accelerator pedal suddenly during fan reverse rotation (fan manual reverse rotation mode). (Refer to Fan Reverse Rotation Control.)

A E

Operation: 1. Main Controller (MC) (1) receives the signal from fan reversing switch (46).

G B

2. When all of the items under the topic below of "Conditions" exist, MC (1) sends a target RPM (min1 ) signal to Engine Control Module (ECM) (15) via Controller Area Network (CAN) communication (12). 3. When the engine speed is lower than idle speed-up speed (fan reverse rotation) (1200 min-1) (F), ECM (15) increases the engine speed to idle speed-up speed (fan reverse rotation) (1200 min-1) (F) from low idle speed (G).

D TNED-02-02-004

A - Engine Speed B - Accelerator Pedal Position C - Accelerator Pedal Position: Not applied D - Accelerator Pedal Position: Fully applied

4. When any of the items under the topic below of "Deactivation Conditions" exists, MC (1) deactivates the idle speed-up control (fan reverse rotation). 5. ECM (15) returns the engine speed (min-1 or RPM) control back to the accelerator pedal (39) position. Conditions:  Forward/Reverse Lever (20) or Forward/Reverse Switch (21) (Option): Neutral Position (c)  When shifting fan reverse rotation or during fan reverse rotation Deactivation Conditions:  Forward/Reverse Lever (20) or Forward/Reverse Switch (21) (Option): Forward Position (a) or Reverse Position (b)  During fan normal rotation

f NOTE: When fan auto-reverse rotation mode is selected, fan reverse rotation idle speed limiter is disabled.

T2-2-18

E-

High Idle Speed (2450 min-1 (RPM)) F - Idle Speed-Up Speed (Fan Reverse Rotation) (1200 min-1 (RPM)) G - Slow Idle Speed (800 min-1 (RPM))

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-027

Forward Position

Reverse Position

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Neutral Position

T2-2-19

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SECTION 2 SYSTEM Group 2 Control System (Blank)

T2-2-20

SECTION 2 SYSTEM Group 2 Control System HST Pump/Motor Control, Transmission Control The Hydrostatic Transmission (HST) pump/motor control and transmission control consist of the followings.  Pump Power Control  Matching Control  Motor Displacement Angle Control  Inching Control  Forward/Reverse Selection Control  Reverse-Acceleration Prevention Control at Forward/ Reverse Selection  Forward/Reverse Lever Priority Control  Manual Speed Shift Control  Clutch Control  Speed Limit Control  Engine Protection Control  Overrun Prevention Control  Overheat Prevention Control  Safety Park Control (On Slope)  Energy Saving Control  HST Alarm Control

T2-2-21

SECTION 2 SYSTEM Group 2 Control System Pump Power Control Purpose: The pump power control controls the pump delivery flow rate in response to the engine speed changes so that the engine output power can be utilized more efficiently.

Operation: 1. Main Controller (MC) (1) receives the signal from power mode switch (44). MC (1) sends the signal to Hydrostatic Transmission (HST) controller (7) by using Controller Area Network (CAN) communication (12).

2. HST controller (7) receives the signal from pressure sensor (front attachment pressure) (18). 3. Engine Control Module (ECM) (15) sends the actual engine speed signals from engine (14) to HST controller (7) by using CAN communication (12). 4. HST controller (7) sends the signals to pump displacement angle control solenoid valve (32) according to the actual engine speed signal detected by CAN communication (12) from ECM (15), power mode switch (44) (ON/OFF), and the front attachment pressure.

N TNDF-02-02-066 N-

Actual Engine Speed

Q-

Pump Displacement Angle (%)

Power Mode OFF

Power Mode ON

5. Pump displacement angle control solenoid valve (32) supplies pilot pressure oil according to the signals to the displacement angle cylinder of HST pump (13) so that the inclination of the pump is changed. 6. Therefore, the delivery flow rate of HST pump (13) varies.

fNOTE: The inclination of the pump is changed by the

accelerator pedal signal and the pressure sensor (front attachment pressure) so that the response is improved and the operation to raise the lift arm while traveling is improved.

fNOTE: The output characteristics of actual engine

speed (N) and pump displacement angle control solenoid valve (32) are different depending on the power mode ON/OFF. (See the following chart)

T2-2-22

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-002

Forward Position

Reverse Position

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MC Column Display Controller Monitor Information Controller MPDr. Air Conditioner Controller HST Controller HST Motor 2 HST Motor 1 Transmission Parking Brake CAN Communication HST Pump/4-Gear Pump Unit Engine ECM

Neutral Position

T2-2-23

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SECTION 2 SYSTEM Group 2 Control System Matching Control Purpose: The matching control limits maximum traction force according to the load during digging operation and prevents the slipping tire in order to raise working efficiency.

 Matching Control Characteristics

Operation: 1. Hydrostatic Transmission (HST) controller (7) receives the signals from HST circuit pressure 1 sensor (33), pressure sensor (front attachment pressure) (18), machine speed 1 sensor (23), and machine speed 2 sensor (24).

C D

2. When all following conditions exist, HST controller (7) sends the signal to motor 1 displacement angle control solenoid valve (26). 3. Motor 1 displacement angle control solenoid valve (26) supplies pilot pressure oil according to the signal of HST controller (7) to the regulator of HST motor 1 (9) so that the maximum inclination of motor 1 is limited.

B TNDF-02-02-020

AB-

4. Therefore, maximum traction force of HST motor 1 (9) is limited. Conditions:  Forward/Reverse Lever (20) or Switch (21) (Option): Forward Position (a)  HST Circuit Pressure 1 Sensor (33): High Pressure (Reference: 20 Mpa (204 kgf/cm2, 2900 psi) or more)  Machine Speed: 5 km/h (3.1 mph) or less

T2-2-24

HST Motor 1 Maximum Tilting Limit (%) Front Attachment Pressure (MPa)

CDE-

Power Mode: ON Power Mode: OFF Traction Control Switch: ON

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-003

Forward Position

Reverse Position

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Neutral Position

T2-2-25

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SECTION 2 SYSTEM Group 2 Control System Motor Displacement Angle Control Purpose: The motor displacement angle control changes the displacement angles of HST motor 1 (9) and HST motor 2 (8) in response to the engine speed changes, and controls the engine speed. Operation: 1. Hydrostatic Transmission (HST) controller (7) receives the signals from machine speed 1 sensor (23), machine speed 2 sensor (24), HST circuit pressure 1 sensor (33), HST circuit pressure 2 sensor (34), and pressure sensor (front attachment pressure) (18). 2. Engine Control Module (ECM) (15) sends the actual engine speed signals from engine (14) to HST controller (7) by using Controller Area Network (CAN) communication (12). 3. HST controller (7) sends the signals to motor 1 displacement angle control solenoid valve (26) and motor 2 displacement angle control solenoid valve (25) according to the actual engine speed signal detected by CAN communication (12) from ECM (15), delivery pressure of HST pump (13), and the front attachment pressure. 4. Motor 1 displacement angle control solenoid valve (26) supplies pilot pressure oil according to the signal to the regulator of HST motor 1 (9) so that the displacement angle of motor 1 is changed. 5. At the same time, motor 2 displacement angle control solenoid valve (25) supplies pilot pressure oil according to the signal to the regulator of HST motor 2 (8) so that the displacement angle is changed. 6. Therefore, the rotation speed of HST motor 1 (9) and HST motor 2 (8) vary.

T2-2-26

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-004

Forward Position

Reverse Position

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Neutral Position

T2-2-27

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SECTION 2 SYSTEM Group 2 Control System Inching Control Purpose: The inching control controls the pump displacement angle in proportion to brake pedal (16) depressing amount, reduces the pump delivery flow rate, and decelerates the vehicle.

fNOTE: The inching control is effective when changing

the front attachment speed, when driving at slow speed (in optional creep mode), and when loading to the truck and hopper.

IMPORTANT: When brake pedal (16) and brake angle sensor (17) have been repaired/replaced, the brake angle sensor learning is required. (Refer to TROUBLESHOOTING S/M / T4-6.) Operation: 1. Hydrostatic Transmission (HST) controller (7) receives the signal from brake angle sensor (17). 2. HST controller (7) sends the signals to pump displacement angle control solenoid valve (32) according to the signals from brake angle sensor (17). 3. Pump displacement angle control solenoid valve (32) supplies pilot pressure oil according to the signals to the displacement angle cylinder of HST pump (13) so that the pump displacement angle is changed. 4. When the brake pedal (16) depressing amount is large, the pump displacement angle is decreased and the delivery flow rate of HST pump (13) is decreased. 5. Therefore, the rotation speed of HST motor 1 (9) and HST motor 2 (8) are decreased.

T2-2-28

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-005

Forward Position

Reverse Position

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Neutral Position

T2-2-29

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SECTION 2 SYSTEM Group 2 Control System Forward/Reverse Selection Control 7. At the same time, HST controller (7) sends the signals from machine speed 1 sensor (23) and forward/reverse lever (20) to column display controller (2) by Controller Area Network (CAN) communication (12).

Purpose: The forward/reverse selection control shifts the traveling direction according to the forward/reverse lever (20) operation and the machine speed at the selected shift range. Operation: 1. Hydrostatic Transmission (HST) controller (7) receives the signals from forward/reverse lever (20), shift switch (19), machine speed 1 sensor (23), and machine speed 2 sensor (24). 2. When the machine speed lowers to the speed that the traveling direction can be shifted, HST controller (7) sends the signals to forward/reverse control solenoid valve (31) according to the signals from forward/reverse lever (20). 3. When forward/reverse lever (20) is in forward position (a) or reverse position (b), forward/reverse control solenoid valve (31) supplies pilot pressure oil according to the signal to the displacement angle cylinder (forward or reverse side) of HST pump (13) so that the inclination direction of the pump is changed.

fNOTE: Machine speed 1 sensor (23) outputs the signals on the rotation direction of HST motor 2 (8) to HST controller (7). 8. Column display controller (2) displays the traveling direction, F/N/R on monitor (3).

fNOTE: When shifting the forward/reverse traveling

direction while traveling, the surge pressure in the HST hydraulic circuit is prevented by controlling the pump inclination command and motor 1/motor 2 inclination command. At the same time, the feeling when shifting the forward/reverse traveling direction becomes proper.

fNOTE: When the signal from forward/reverse switch

4. Therefore, pressure oil from HST pump (13) is delivered through the port (forward or reverse side) and shifts the rotation direction of HST motor 1 (9) and HST motor 2 (8). 5. When forward/reverse lever (20) is in neutral position (c), forward/reverse control solenoid valve (31) is set to the neutral position due to no input signals. Pilot pressure oil returns to the tank port through the neutral circuit. 6. Therefore, as pressure oil from HST pump (13) is not delivered, HST motor 1 (9) and HST motor 2 (8) stop rotating.

T2-2-30

(21) (option) is effective, the forward/reverse selection control is performed by operating forward/reverse switch (21).

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-006

Forward Position

Reverse Position

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Neutral Position

T2-2-31

363738394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Reverse-Acceleration Prevention Control at Forward/Reverse Selection Purpose: The reverse-acceleration prevention control at forward/ reverse selection limits the engine speed in order to prevent the traveling speed from accelerating due to unexpected accelerator pedal operation during the forward/reverse selection control. (The speed increase rate is limited.) Operation: 1. When any following conditions exist during the forward/reverse selection control, Hydrostatic Transmission (HST) controller (7) sends the signals the actual engine speed signal detected by Controller Area Network (CAN) communication (12) from Engine Control Module (ECM) (15) to Main Controller (MC) (1). 2. MC (1) sends the signals equivalent to the target engine speed to ECM (15) by using CAN communication (12). 3. ECM (15) limits the engine speed according to CAN communication (12) from MC (1). Conditions:  When the signal, F/N/R and the signal from machine speed 1 sensor (23) are different  When forward/reverse lever (20) or switch (21) (option) is set to neutral position (c) and machine speed is 5 Km/h (3.1 mph) or more 4. When the following deactivation conditions exist, ECM (15) returns the engine speed according to the accelerator pedal control. Deactivation Condition:  When the signal, F/N/R and the signal from machine speed 1 sensor (23) are the same. NOTE: Machine speed 1 sensor (23) outputs the signals on the rotation direction of HST motor 2 (8) to HST controller (7).

T2-2-32

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-007

Forward Position

Reverse Position

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Neutral Position

T2-2-33

363738394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Forward/Reverse Lever Priority Control (Option) Purpose: The forward/reverse lever (20) is given priority over the forward/reverse switch (21) when the machine forward/ reverse movement is controlled by forward/reverse switch (21) (option). Operation: 1. Forward/reverse lever (20), forward/reverse switch (21) (option), and forward/reverse selector switch (22) (option) all send a signal to Hydrostatic Transmission (HST) controller (7). 2. When any of the following items listed below under "Conditions" exists, HST controller (7) makes the signal from forward/reverse lever (20) effective and the forward/reverse selection control is perform. (Refer to Forward/Reverse Selection Control.) Conditions:  When forward/reverse lever (20) is in neutral position (c) and forward/reverse selector switch (22) is in the OFF position  Forward/Reverse Lever (20): Operated  Key Switch (43): OFFON  Forward/Reverse Switch: Defective 3. At the same time, HST controller (7) sends the signal from forward/reverse lever (20) to column display controller (2) by Controller Area Network (CAN) communication (12). 4. Column display controller (2) displays the traveling direction, F/N/R on monitor (3).

T2-2-34

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-008

Forward Position

Reverse Position

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Neutral Position

T2-2-35

363738394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Speed Shift Control Purpose: The speed shift control shifts the speed shift according to the shift switch (19) operation and the machine speed at the selected shift range. Operation: 1. Hydrostatic Transmission (HST) controller (7) receives the signals from shift switch (19), machine speed 1 sensor (23), and machine speed 2 sensor (24).

fNOTE: Two switches (SW1, SW2) are located in shift

switch (19). The signal of the selected speed shift position is sent to HST controller (7) according to the ON/OFF combination of the switches. 2. When the machine speed lowers to the speed that the speed shift can be changed, HST controller (7) changes the current speed shift signal into the selected speed shift signal. Therefore, HST controller (7) makes the clutch control possible. (Refer to Clutch Control.) 3. At the same time, HST controller (7) sends the selected speed shift signal to column display controller (2) by Controller Area Network (CAN) communication (12). 4. Column display controller (2) displays 1/2/3/4 according to the current speed shift on monitor (3).

fNOTE: The speed shift is four speed in forward and four speed in reverse. 5. When the machine speed increases beyond the speed that the speed shift can be changed due to sudden speed shifting (first or second from fourth, first from third), HST controller (7) turns the shift change alarm signal ON.

6. When the machine speed lowers to the speed that the speed shift can be changed, HST controller (7) turns the shift change alarm signal OFF.

T2-2-36

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-009

Forward Position

Reverse Position

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Neutral Position

T2-2-37

363738394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Clutch Control

 Disconnecting the clutch 1. HST controller (7) sends the signals to motor 1 displacement angle control solenoid valve (26) and clutch pressure control solenoid valve (27) according to the actual engine speed signal and machine speed detected by CAN communication (12) from ECM (15) (speed shift: 3rd or 4th speed).

Purpose: The clutch control connects/disconnects the clutch of transmission (10) according to the machine speed (speed shift: 3rd or 4th speed) and shifts traveling speed (fast/ slow). IMPORTANT: When Hydrostatic Transmission (HST) controller (7) and transmission (10) have been repaired/replaced, the clutch learning is required. (Refer to TROUBLESHOOTING S/M / T4-6.)

2. Motor 1 displacement angle control solenoid valve (26) supplies pilot pressure oil according to the signal to the regulator of HST motor 1 (9) so that the displacement angle of motor 1 becomes minimum. 3. Clutch pressure control solenoid valve (27) stops supplying pilot pressure oil according to the signal so that the clutch is disconnected.

Operation: 1. HST controller (7) receives the signals from machine speed 1 sensor (23), machine speed 2 sensor (24), and shift switch (19).

4. Therefore, the input and output shafts at the HST motor 1 (9) side of transmission (10) are disconnected and traveling speed is changed into fast speed (3rd/ 4th).

2. Engine Control Module (ECM) (15) sends the actual engine speed signals from engine (14) to HST controller (7) by using Controller Area Network (CAN) communication (12). 3. Main Controller (MC) (1) sends the signal from accelerator pedal (39) to HST controller (7) by using CAN communication (12).  Connecting the clutch 1. HST controller (7) sends the signals to clutch pressure control solenoid valve (27) according to the accelerator pedal signal and machine speed detected by CAN communication (12) from MC (1). 2. Clutch pressure control solenoid valve (27) supplies pilot pressure oil according to the signal to the clutch of transmission (10) so that the clutch is connected.

5. When any following conditions exist, the clutch is forcibly connected and traveling speed is changed into slow speed (1st/ 2nd). Conditions:  During forward/reverse selection control: Machine Speed: 3.5 km/h (2.2 mph) or less  Except during forward/reverse selection control: Machine Speed: 6 km/h (3.7 mph) or less, HST circuit pressure 1, 2: High (Reference: 25 MP (255 kgf/cm2) (3626 psi) or less)  Except during forward/reverse selection control: Machine Speed: 0 km/h (0 mph) or less (Stopped)

3. Therefore, two input shafts at the HST motor 1 (9) and HST motor 2 (8) sides of transmission (10) are connected and traveling speed is changed into slow speed (1st/ 2nd).

T2-2-38

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-012

Forward Position

Reverse Position

123456789101112131415-

Neutral Position

T2-2-39

363738394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Speed Limit Control

 Slow speed mode 1. When all following conditions exist, HST controller (7) sends the signal to pump displacement angle control solenoid valve (32).

Purpose: The speed limit control limits the machine speed according to the speed limit selection mode.

2. Pump displacement angle control solenoid valve (32) supplies pilot pressure oil according to the signals to the displacement angle cylinder of HST pump (13) so that the minimum displacement angle of pump (13) is limited.

fNOTE: The speed limit mode consists of two modes, standard and slow.

Operation: 1. Main Controller (MC) (1) receives the signal from 1st speed limit switch (42). MC (1) sends the speed limit value signal to Hydrostatic Transmission (HST) controller (7) by using Controller Area Network (CAN) communication (12).

NOTE: 1st speed limit switch (42) is a variable switch. It can adjust the machine speed within the range according to the speed limit selection mode. 2. HST controller (7) receives the signal from shift switch (19). HST controller (7) performs the speed limit control according to the speed limit mode signal, current speed shift signal, and speed limit value signal.

3. Therefore, the delivery flow rate of HST pump (13) is decreased so that max. speed at 1st speed is limited within 7 km/h (4.3 mph) in the maximum. Conditions:  Creep Switch (47) (Option): ON  Speed Shift: First Speed (Forward/Reverse) NOTE: When creep switch (47) (Option) is in the OFF position, the speed limit mode: Standard is selected.

 Standard mode 1. When all following conditions exist, HST controller (7) sends the signal to motor 1 displacement angle control solenoid valve (26). 2. Motor 1 displacement angle control solenoid valve (26) supplies pilot pressure oil according to the signal to the regulator of HST motor 1 (9) so that the minimum displacement angle of motor 1 is limited. 3. Therefore, the rotation speed of HST motor 1 (9) is decreased so that max. speed at 1st speed is limited between 7 km/h (4.3 mph) and the max. speed at 2nd speed. Conditions:  Speed Limit Mode: Standard  Creep Switch (47) (Option): OFF  Speed Shift: First Speed (Forward/Reverse) NOTE: In case the limit value of the motor 1 maximum displacement angle during matching control is beyond the limit value of the motor 1 minimum displacement angle during speed limit control, priority is given to matching control.

T2-2-40

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-010

Forward Position

Reverse Position

123456789101112131415-

Neutral Position

T2-2-41

363738394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Engine Protection Control Purpose: The engine protection control decreases the engine speed to a safe level to prevent the excessive engine revolution by operating the Hydrostatic Transmission (HST) brake while running at the fast speed. Operation: 1. Engine Control Module (ECM) (15) sends the actual engine speed signals from engine (14) to HST controller (7) by using Controller Area Network (CAN) communication (12). 2. When all following conditions exist, HST controller (7) sends the signals to motor 2 displacement angle control solenoid valve (25) according to the actual engine speed signal detected by CAN communication (12) from ECM (15). 3. Motor 2 displacement angle control solenoid valve (25) supplies pilot pressure oil according to the signal to the regulator of HST motor 2 (8) so that the maximum displacement angle of motor 2 is limited.

fNOTE: It controls the tilting speed of motor 2 in order to reduce the vehicle shock and the slipping tire developed when changing the displacement angle during engine protection control.

4. Therefore, the rotation speed of HST motor 2 (8) is increased and the engine speed is decelerated. Conditions:  Speed Shift: Third or Fourth  Actual Engine Speed: 2800 min-1

T2-2-42

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-011

Forward Position

Reverse Position

123456789101112131415-

Neutral Position

T2-2-43

363738394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Overrun Prevention Control Purpose: The overrun prevention control applies the Hydrostatic Transmission (HST) brake and returns the machine speed to the allowable speed when the machine speed at each speed shift is beyond the allowable speed. Operation:  Speed Shift: 1st or 2nd speed 1. When all following conditions exist (speed shift: 1st or 2nd speed), HST controller (7) sends the signal to motor 1 displacement angle control solenoid valve (26). 2. Motor 1 displacement angle control solenoid valve (26) supplies pilot pressure oil according to the signal to the regulator of HST motor 1 (9) so that the displacement angle of motor 1 becomes maximum. 3. Therefore, the rotation speed of HST motor 1 (9) is decreased and the machine speed is decelerated.  Speed Shift: 3rd, 4th speed 1. When all following conditions exist (speed shift: 3rd, 4th speed), HST controller (7) sends the signal to motor 2 displacement angle control solenoid valve (25). 2. Motor 2 displacement angle control solenoid valve (25) supplies pilot pressure oil according to the signal to the regulator of HST motor 2 (8) so that the displacement angle of motor 2 becomes maximum. 3. Therefore, the rotation speed of HST motor 2 (8) is decreased and the machine speed is decelerated. Conditions: Speed Shift: 1st or 2nd speed:  Forward/Reverse Lever (20) or Switch (21) (Option): Forward Position (a) or Reverse Position (b)  Machine Speed: 14 km/h (8.7 mph) or more Speed Shift: 3rd speed:  Forward/Reverse Lever (20) or Switch (21) (Option): Forward Position (a) or Reverse Position (b)  Machine Speed: 24 km/h (15 mph )or more Speed Shift: 4th speed:  Forward/Reverse Lever (20) or Switch (21) (Option): Forward Position (a) or Reverse Position (b)  Machine Speed: 38 km/h (23.6 mph) or more (62Z7) Machine Speed: 42 km/h (26 mph) or more (67Z7) NOTE: The HST alarm indictor and maintenance indictor blink and the buzzer sounds during overrun prevention control.

T2-2-44

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-013

Forward Position

Reverse Position

123456789101112131415-

Neutral Position

T2-2-45

363738394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Overheat Prevention Control Purpose: The overheat prevention control limits the machine speed and prevents the engine overheating when radiator coolant and hydraulic oil temperatures reach their upper limit. Operation: 1. Engine Control Module (ECM) (15) receives signals from coolant temperature sensor (37). ECM (15) sends a signals to Hydrostatic Transmission (HST) controller (7) via Controller Area Network (CAN) communication (12). 2. Main Controller (MC) (1) receives a signal from HST oil temperature sensor (41). MC (1) sends the signal to HST controller (7) via CAN communication (12). 3. When any of the items under the topic below of "Conditions" exists, HST controller (7) sends a signal to motor 1 displacement angle control solenoid valve (26). 4. Motor 1 displacement angle control solenoid valve (26) supplies pilot pressure oil according to the signal to the regulator of HST motor 1 (9) to limit the minimum displacement angle of motor 1 (9). 5. Therefore, the rotation speed of HST motor 1 (9) is decreased and the machine is decelerated. Conditions:  Coolant Temperature: 95 °C (203 °F) or more  Hydraulic Oil Temperature: 95 °C (203 °F) or more 6. When any of the items under the topic below of "Deactivation Conditions" exists, HST controller (7) deactivates the overheat prevention control. Deactivation Conditions:  During overrun prevention control  During forward/reverse selection control

T2-2-46

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-014

Forward Position

Reverse Position

123456789101112131415-

Neutral Position

T2-2-47

363738394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Safety Park Control (On Slope) Purpose: The safety park control prevents the vehicle from slipping down on a slope. Operation: 1. Main Controller (MC) (1) sends the signal from accelerator pedal sensor (40) to Hydrostatic Transmission (HST) controller (7) by using Controller Area Network (CAN) communication (12). 2. HST controller (7) receives the signal from machine speed 1 sensor (23). 3. When all following conditions exist, HST controller (7) sends the signals to motor 1 displacement angle control solenoid valve (26) according to the accelerator pedal signal and machine speed detected by CAN communication (12) from MC (1). 4. Motor 1 displacement angle control solenoid valve (26) supplies pilot pressure oil according to the signal to the regulator of HST motor 1 (9) so that the displacement angle of motor 1 becomes maximum. 5. Therefore, HST motor 1 (9) is difficult to rotate on a slope and the vehicle is prevented from slipping down. Conditions:  Machine Speed: Less than 0.5 km/h (0.31 mph)  Forward/Reverse Lever (20) or Switch (21) (Option): Neutral Position (c)

fNOTE: When the forward/reverse lever (20) operation

(the signal, F/N/R) and the traveling direction are different on a slope and machine speed is 0.2 km/h (0.12 mph) or more, the displacement angle of motor 1 becomes maximum.

fNOTE: Machine speed 1 sensor (23) outputs the signals on the rotation direction of HST motor 2 (8) to HST controller (7).

T2-2-48

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-015

Forward Position

Reverse Position

123456789101112131415-

Neutral Position

T2-2-49

363738394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Energy Saving Control Purpose: The energy saving control filters when running the engine until the target engine speed with the power mode OFF. In addition, it limits the engine speed and reduces the displacement angle of motor 1 when the machine speed at each speed shift is maximum in order to reduce fuel consumption and keeps the max. speed. Operation: 1. Main Controller (MC) (1) receives the signals from accelerator pedal sensor (40) and power mode switch (44). MC (1) sends the signal to Hydrostatic Transmission (HST) controller (7) by using Controller Area Network (CAN) communication (12). 2. Engine Control Module (ECM) (15) sends the actual engine speed signals from engine (14) to HST controller (7) by using CAN communication (12). 3. When the power mode is OFF (standard mode), HST controller (7) sends the signal equivalent to the target engine speed to ECM (15) by using CAN communication (12). 4. When the engine speed is faster than the speed at energy saving control, ECM (15) reduces and limits the engine speed to specified value (reference: 2000 min-1) according to CAN communication (12). 5. HST controller (7) sends the signal to motor 2 displacement angle control solenoid valve (25) in step 4. 6. Motor 2 displacement angle control solenoid valve (25) supplies pilot pressure oil according to the signal to the regulator of HST motor 2 (8) so that the displacement angle of motor 2 becomes minimum. 7. Therefore, the max. speed at each speed shift is kept while limiting the engine speed.

T2-2-50

SECTION 2 SYSTEM Group 2 Control System 39

41 42

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-016

Forward Position

Reverse Position

123456789101112131415-

Neutral Position

T2-2-51

363738394041424344454647-

SECTION 2 SYSTEM Group 2 Control System HST Alarm Control Purpose: The Hydrostatic Transmission (HST) alarm control detects abnormality and lights the indicator in case the sensors, switches, and control solenoid valves related with the HST control are abnormal. Operation: 1. HST controller (7) sends the signal to column display controller (2) by using Controller Area Network (CAN) communication (12) in case abnormality is found with the following sensors, switches, and control solenoid valves related to the HST control.  Main Controller (MC)(1), Engine Control Module (ECM)(15): CAN communication error  Clutch learning failure: Not Learn  Brake Angle Sensor (17): Not Learn  Forward/Reverse Lever (20) or Switch (21) (Option)  Machine Speed 1 Sensor (23)  Machine Speed 2 Sensor (24)  Pressure sensor (Front Attachment Pressure) (18)  HST Circuit Pressure 1 Sensor (33) (Forward Side)  HST Circuit Pressure 2 Sensor (34) (Reverse Side)  Forward/Reverse Control Solenoid Valve (31)  Pump Displacement Angle Control Solenoid Valve (32)  Motor 1 Displacement Angle Control Solenoid Valve (26)  Motor 2 Displacement Angle Control Solenoid Valve (25)  Clutch Pressure Control Solenoid Valve (27) 2. Column display controller (2) lights HST alarm indictor (49) and maintenance indictor (50).

T2-2-52

SECTION 2 SYSTEM Group 2 Control System 39

41 42

49 50

43 3

44 45

20, 21

12 29 28 24

38 37 36 35

15 32

31 10 9

26 27 34 33

TNDF-02-02-017

Forward Position

Reverse Position

123456789101112131415-

Neutral Position

T2-2-53

363738394041424344454647-

SECTION 2 SYSTEM Group 2 Control System (Blank)

T2-2-54

SECTION 2 SYSTEM Group 2 Control System Fan Control, Valve Control The fan control and valve control consist of the followings.  Fan Speed Control  Fan Reverse Rotation Control  Ride Control  Exhaust Filter Manual Regeneration Control  Exhaust Filter Auto Regeneration Control

T2-2-55

SECTION 2 SYSTEM Group 2 Control System Fan Speed Control Purpose: The fan speed control optimizes the fan speed depending on engine speed, hydraulic oil temperature, engine coolant temperature, and so on. Operation: 1. The following items provide inputs to Main Controller (MC) (1) via Controller Area Network (CAN) communication (12).  Crank speed sensor (35) signal, from ECM (15)  Cam angle sensor (36) signal, from ECM (15)  Coolant temperature sensor (37) signal, from ECM (15)  Boost temperature sensor (38), from ECM (15)  Outside temperature sensor (49), from HVAC controller (6)  Boost temperature sensor (38), from ECM (15)  Boost temperature sensor (38), from ECM (15)  Power mode selector switch (44) signal  HST oil temperature sensor (41) signal  HVAC refrigerant pressure sensor (48) 2. MC (1) optimizes the signal sent to fan speed control solenoid valve (53) as adjusted by the input signals shown in the above listed items.

T2-2-56

SECTION 2 SYSTEM Group 2 Control System

49 5

43 3

44 1

2 7 12 29 28 30

38 37 36 35

8 10 9

13 14

53 52

50 TNDF-02-02-030

1234567891011-

MC Column Display Controller Monitor Information Controller MPDr. Air Conditioner Controller HST Controller HST Motor 2 HST Motor 1 Transmission Parking Brake

12131415282930353637-

CAN Communication HST Pump/4-Gear Pump Unit Engine ECM Pressure Sensor (Parking Brake) Parking Brake Switch Parking Brake Solenoid Valve Crank Speed Sensor Cam Angle Sensor Coolant Temperature Sensor

38394041434448-

Boost Temperature Sensor Accelerator Pedal Accelerator Pedal Sensor HST Oil Temperature Sensor Key Switch Power Mode Switch Pressure Sensor (Refrigerant Pressure) 49- Outside Temperature Sensor 50- Fan Motor 51- Fan Reverse Rotation Spool

T2-2-57

52- Fan Reverse Rotation Control Solenoid Valve 53- Fan Speed Control Solenoid Valve 54- Pressure Sensor (Primary Pilot Pressure) 55- Fan Valve 56- Fan Reversing Switch 57- Fan Reverse Rotation Indicator

SECTION 2 SYSTEM Group 2 Control System Fan Reverse Rotation Control 7. Column display controller (2) receives the signals from pressure sensor (parking brake) (28).

Purpose: The fan reverse rotation control reverses the rotation of the cooling fan from the normal rotation direction by operating the fan reversing switch (56).

8. Hydrostatic Transmission (HST) controller (7) sends the ON/OFF signal of the parking brake to MC (1) by using CAN communication (12).

fNOTE: As the cooling fan direction is reversed, dust that

9. MC (1) holds the fan in reverse rotation until the key switch is turned OFF when fan manual reversing switch (56) is set to manual-reverse rotation position with the parking brake applied.

has lodged in the radiator and oil cooler is discharged, helping to clear the cooling elements of blockage.

Operation: 1. Main Controller (MC) (1) receives the signal from fan reversing switch (56). 2. MC (1) activates fan reverse rotation control solenoid valve (52) in fan valve (55) and shifts fan reversing spool (51) when fan reversing switch (56) is set to manual-reverse rotation position.

11. MC (1) sends the ON signal to column display controller (2) by using CAN communication (12) during fan reverse rotation control. 12. Column display controller (2) lights fan reverse rotation indicator (57).

3. Therefore, fan motor (50) rotates in reverse. 4. MC (1) activates fan speed control solenoid valve (53) at the same time and fixes the fan rotation speed at 1220 min-1 (specified value).

fNOTE: The fan automatic reverse rotation can be set

5. MC (1) rotates fan motor (50) in the normal direction by pushing the manual-reverse rotation position of fan reversing switch (56) once more. 6. In addition, MC (1) sets to the fan speed control to control the fan rotation speed according to the hydraulic oil temperature and so on. (Refer to Fan Speed Control.)

10. MC (1) makes fan motor rotate in normal after holding the fan reverse rotation for one minute with the parking brake released.

with MPDr. (5).

Fan automatic reverse rotation: MC (1) performs the following operation when setting fan reverse rotation switch (56) to the automatic reverse rotation position.  Normal rotation (10 minutes)  Reverse rotation (1 minute)  Normal rotation (30 minutes)  Reverse rotation (1 minute)  Normal rotation (30 minutes). These are repeated.  The fan reverse rotation hour is 90 seconds when outside temperature is low.

fNOTE: When the cooling fan rotation is changed, it

reverses the direction of air flow; what was the outlet side is now the inlet side, and what was the inlet side is now the outlet side.

T2-2-58

SECTION 2 SYSTEM Group 2 Control System

57 5

43 3

44 1

2 7 12 29 28 30

38 37 36 35

8 10 9

13 14

53 52

50 TNDF-02-02-031

1234567891011-

Main Controller (MC) Column Display Controller Monitor Information Controller MPDr. Air Conditioner Controller HST Controller HST Motor 2 HST Motor 1 Transmission Parking Brake

12131415282930353637-

CAN Communication HST Pump/4-Gear Pump Unit Engine ECM Pressure Sensor (Parking Brake) Parking Brake Switch Parking Brake Solenoid Valve Crank Speed Sensor Cam Angle Sensor Coolant Temperature Sensor

38394041434448-

T2-2-59

SECTION 2 SYSTEM Group 2 Control System Ride Control Purpose: The ride control reduces the fore and aft pitching that normally occurs while moving a wheel loader over uneven terrain by organizing a damper circuit in the lift arm cylinder. This is helpful to reduce operator discomfort and material spillage from the bucket. Operation: 1. Hydrostatic Transmission (HST) controller (7) receives the signals from pressure sensor (front attachment pressure) (18), machine speed 1 sensor (23), and machine speed 2 sensor (24). HST controller (7) sends the signals to Main Controller (MC) (1) via Controller Area Network (CAN) communication (12).

7. MC (1) sends the signals to column display controller (2) by using CAN communication (12) at the same time. 8. Column display controller (2) displays the ride control state on monitor (3).

fNOTE: The machine speed of ride control at the Auto

mode can be set by using MPDr. (5). The setting range of machine speed is 3 to 18 km/h (1.9 to 11 mph).

fNOTE: OFF and AUTO mode can be selected as for ride control switch (48).

fNOTE: When the following parts become abnormal, the

2. MC (1) receives a signal from ride control switch (48). MC (1) monitors the machine speed when ride control switch (48) is set to the AUTO mode. 3. MC (1) energizes ride control solenoid valve coil (49) when machine speed is beyond the specified value to turn on ride control, and permits pilot oil to shift ride control spool (52) in control valve (50). 4. When this occurs, a damper circuit is organized between the rod side and bottom side of lift arm cylinder (53) by directing oil to designated circuits. 5. The damper circuit absorbs and dissipates the fore and aft pitching energy caused from the up and down movement of the lift arms while running over uneven terrain. The rod end of lift arm cylinder (53) will open to the tank circuit so that there is minimal latent vacuum at the rod side of the circuit. The base end of lift arm cylinder (53) opens to work against accumulator (51) to absorbs the fore and aft pitching shock cycles. 6. MC (1) deactivates the ride control when machine speed falls below the point of ride control engagement. When the items shown below under the topic of "Temporary Deactivation Condition" exists, MC (1) deactivates the ride control system to temporarily cease to operate. Temporary Deactivation Condition:  Lift Arm Raise Operation (Pressure Sensor (Front Attachment Pressure) (18)): Beyond specified value (Reference: 13 MPa, 132 kgf/cm2, 1886 psi or more)

T2-2-60

ride control is deactivated.  Machine Speed 1 Sensor (23)  Machine Speed 2 Sensor (24)  Pressure Sensor (Front Attachment Pressure) (18)

SECTION 2 SYSTEM Group 2 Control System

40 18 5

48 1

2 7

53 12 29 28

30 36 35

8 10

9 13

52 14 50

TNDF-02-02-032

123456789-

Main Controller (MC) Column Display Controller Monitor Information Controller MPDr. Air Conditioner Controller HST Controller HST Motor 2 HST Motor 1

10111213141518-

Transmission Parking Brake CAN Communication HST Pump/4-Gear Pump Unit Engine ECM Pressure Sensor (Front Attachment Pressure) 23- Machine Speed 1 Sensor

24- Machine Speed 2 Sensor 28- Pressure Sensor (Parking Brake) 29- Parking Brake Switch 30- Parking Brake Solenoid Valve 35- Crank Speed Sensor 36- Cam Angle Sensor 39- Accelerator Pedal 40- Accelerator Pedal Sensor

T2-2-61

484950515253-

Ride Control Switch Ride Control Solenoid Valve Ride Control Valve Accumulator Spool Lift Arm Cylinder

SECTION 2 SYSTEM Group 2 Control System Exhaust Filter Manual Regeneration Control Purpose: The exhaust filter manual regeneration control cleans (regenerates) the exhaust filter manually when exhaust filter regeneration switch (49) is set to the manual regeneration position. As it increases the pump load during exhaust filter regeneration, the load is applied to the engine. Therefore, the exhaust temperature increases up to the temperature that a catalyst in the exhaust filter is activated.

6. When the items under the topic "Deactivation Condition" exists, or any of the topic "Conditions" is not satisfied, MC (1) deactivates the exhaust filter manual regeneration control and regeneration will not occur. When the engine is too cool to clean the exhaust filter manually, ECM (8) holds the minimum engine RPM's to specified value (1000 RPM's (min-1)) so the engine will warm up quickly.

IMPORTANT: When exhaust filter regeneration request (yellow) indicator (55) of column display controller (2) lights or blinks and the buzzer sounds, regenerate the exhaust filter manually immediately.

Deactivation Condition:  HST (Hydraulic) Oil Temperature: 91 °C (196 °F) or higher

Operation: 1. Engine Control Module (ECM) (15) sends the exhaust filter request signal to Main Controller (MC) (1) according to the input signal from each sensor of the exhaust filter by using Controller Area Network (CAN) communication (12).

fNOTE: When exhaust filter regeneration switch (49) is in

7. Exhaust filter regeneration display (59) on monitor (3) lights during exhaust filter manual regeneration. the exhaust filter regeneration inhibit position, exhaust filter regeneration inhibit indicator (57) lights.

fNOTE: When exhaust filter regeneration switch (49) is in

2. When all following items under the topic of "Conditions" exist, MC (1) activates exhaust filter regeneration control solenoid valve (50), and pilot pressure oil (PibX) moves exhaust filter regeneration spool (52) in control valve (51).

the exhaust filter regeneration inhibit position and the exhaust filter regeneration request is generated, exhaust filter regeneration inhibit indicator (yellow) (56) lights.

3. As the pressurized oil in main pump (54) is routed through orifice (53) in the main circuit, increases the circuit pressure, applies the load to engine (14).

4. When the coolant or exhaust temperature is too low, regeneration cannot start. When the coolant temperature is low, MC (1) sends the target RPM signal to ECM (15) via CAN communication (12) to warm the engine quickly. 5. ECM (15) increases the engine speed and coolant temperature rises. Conditions:  Accelerator Pedal (39) Position: Not applied  Parking Brake: In Operation  Forward/Reverse Lever (20) or Switch (21) (Option): Neutral Position (c)  Front Control Lever Lock: In Operation (Pressure Sensor (Primary Pilot Pressure) (48): Below specified value)  Exhaust filter regeneration switch (49): Manual regeneration position

T2-2-62

MNDB-01-008

SECTION 2 SYSTEM Group 2 Control System

41 48

55 56 57

20, 21

49 1

c b

7 52 53 50

29 28

PibX

30 15

8 10 9

13 14 54

TNDF-02-02-033

Forward Position

Reverse Position

12345678910111213-

14152021-

Engine ECM Forward/Reverse Lever Forward/Reverse Switch (Option) Forward/Reverse Selector Switch (Option) Pressure Sensor (Parking Brake) Parking Brake Switch Parking Brake Solenoid Valve Crank Speed Sensor Cam Angle Sensor

3738394041434448-

222829303536-

Neutral Position

Coolant Temperature Sensor Boost Temperature Sensor Accelerator Pedal Accelerator Pedal Sensor HST Oil Temperature Sensor Key Switch Power Mode Switch Pressure Sensor (Primary Pilot Pressure) 49- Exhaust Filter Regeneration Switch 50- Exhaust Filter Regeneration Control Solenoid Valve

T2-2-63

PibX- Exhaust Filter Regeneration 51- Control Valve 52- Exhaust Filter Regeneration Spool 53- Orifice 54- Main Pump 55- Exhaust Filter Regeneration Request (Yellow) Indicator 56- Exhaust Filter Regeneration Inhibit Indicator (Yellow) 57- Exhaust Filter Regeneration Inhibit Indicator 58- Buzzer

SECTION 2 SYSTEM Group 2 Control System Exhaust Filter Auto Regeneration Control Purpose: The exhaust filter auto regeneration control cleans (regenerates) the exhaust filter according to the machine state automatically. Since this process requires engine heat, the engine is heated by means of a hydraulic restriction being imposed on the pump. This increases the engine workload temperature resulting in higher heat at the exhaust filter and the filter cleaning is activated. Operation: 1. Engine Control Module (ECM) (15) sends the exhaust filter request signal to Main Controller (MC) (1) according to the input signal from each sensor of the exhaust filter by using Controller Area Network (CAN) communication (12). 2. When all the items under the topic of "Conditions" exist, MC (1) activates exhaust filter regeneration control solenoid valve (50), and pilot pressure oil (PibX) moves exhaust filter regeneration spool (52) in control valve (51).

6. When the item under the topic "Deactivation Conditions" exists, or any of the topic "Conditions" is not satisfied, MC (1) deactivates the exhaust filter auto regeneration control and stops imposing restriction on the pump (auto regeneration can continue). When the engine is too cool to clean the exhaust filter manually, ECM (8) holds the minimum engine RPM's to specified value (1000 RPM's (min-1)) so the engine will warm up quickly. Deactivation Condition:  HST (Hydraulic) Oil Temperature: 91 °C (196 °F) or more 7. Exhaust filter regeneration display (59) on monitor (3) lights during exhaust filter auto regeneration.

fNOTE: When exhaust filter regeneration switch (49) is in

3. As the pressurized oil in main pump (54) is routed through orifice (53) in the main circuit, increases the circuit pressure, applies the load to engine (14).

the exhaust filter regeneration inhibit position, exhaust filter regeneration inhibit indicator (57) lights and the exhaust filter is not regenerated automatically.

4. MC (1) sends the signals equivalent to the target engine speed to ECM (15) via CAN communication (12) during exhaust filter auto regeneration. 5. ECM (15) increases the engine speed to 1000 RPM's (min-1).

Conditions:

 The output signal from the differential pressure sensor is beyond the specified value after or before eight hours have passed since the last regeneration. (ECM judges.)  Accelerator Pedal (39) Position: Not applied  Parking Brake: In Operation  Forward/Reverse Lever (20) or Switch (21) (Option): Neutral Position (c)  Front Control Lever Lock: In Operation (Pressure Sensor (Primary Pilot Pressure) (49): Below specified value)

MNDB-01-008

IMPORTANT: When exhaust filter regeneration inhibit indicator (yellow) (56) of column display controller (2) lights, the exhaust filter is not regenerated automatically.

T2-2-64

SECTION 2 SYSTEM Group 2 Control System

41 48

55 56 57

20, 21

49 1

c b

7 52 53 50

29 28

PibX

30 15

8 10 9

13 14 54

TNDF-02-02-033

Forward Position

Reverse Position

12345678910111213-

14152021-

3738394041434448-

222829303536-

Neutral Position

T2-2-65

SECTION 2 SYSTEM Group 2 Control System (Blank)

T2-2-66

SECTION 2 SYSTEM Group 2 Control System Other Controls The other controls consist of the followings.  Low Brake Oil Pressure Indicator Control  Low Steering Oil Pressure Indicator Control (Option)  Lift Arm Auto Leveler Height Kickout Control (Option)  Lift Arm Auto Leveler Lower Kickout Control (Option)  Auto Idling Stop Control (Not used)  Secondary Steering Control (Option)

T2-2-67

SECTION 2 SYSTEM Group 2 Control System Low Brake Oil Pressure Indicator Control Purpose: Main Controller (MC) (1) sends a signal to column display controller (2) to illuminate the low oil brake pressure indicator (7) on the monitor control panel when the service brake pressure circuit falls below a safe level. Operation: 1. When the service brake pressure circuit is below 8.1 MPa (83 kgf/cm2, 1175 psi or less), at primary brake pressure sensor (5), MC (1) sends OFF signal to column display controller (2) in 0.8 seconds. 2. Column display controller (2) illuminates low brake oil pressure indicator (7). 3. When the service brake pressure circuit is well above 10.0 MPa (102 kgf/cm2, 1450 psi or more) at primary brake pressure sensor (5), MC (1) sends ON signal to column display controller (2). 4. Column display controller (2) turns OFF low brake oil pressure indicator (7).

fNOTE: When pressure sensor (brake primary pressure) (5) malfunctions, low brake oil pressure indicator (7) illuminates and remains ON.

T2-2-68

SECTION 2 SYSTEM Group 2 Control System

3 2

4 TNDF-02-02-035

123-

MC Column Display Controller Monitor

45-

CAN Communication Pressure Sensor (Brake Primary Pressure)

67-

T2-2-69

Steering Pressure Switch Low Brake Oil Pressure Indicator

Low Steering Oil Pressure Indicator

SECTION 2 SYSTEM Group 2 Control System Low Steering Oil Pressure Indicator Control (Option) Purpose: The low steering oil pressure indicator control illuminates the steering indicator on the monitor control panel when steering oil pressure is below the specified value. Operation: 1. When steering oil pressure is below the secondary steering response level threshold and triggers steering pressure switch (6): to open the circuit between the switch and Main Controller (MC) (1), MC (1) sends the OFF signal to column display controller (2). 2. Column display controller (2) illuminates low steering oil pressure indicator (8). 3. MC (1) also engages the secondary steering system (option), if equipped, as determined by operating conditions. (Refer to Secondary Steering Control.) 4. When steering oil pressure is above the specified level, steering pressure switch (6) closes (turns ON), providing this input to MC (1). Then, MC (1) sends ON signal to column display controller (2). 5. Column display controller (2) turns OFF low steering oil pressure indicator (8).

fNOTE: Steering pressure switch (6) is not equipped without the secondary steering system option. This control does not exist and low steering oil pressure indicator (8) keeps OFF.

T2-2-70

SECTION 2 SYSTEM Group 2 Control System

3 2

4 TNDF-02-02-034

123-

MC Column Display Controller Monitor

45-

CAN Communication Pressure Sensor (Brake Primary Pressure)

67-

T2-2-71

Steering Pressure Switch Low Brake Oil Pressure Indicator

Low Steering Oil Pressure Indicator

SECTION 2 SYSTEM Group 2 Control System Lift Arm Auto Leveler Height Kickout Control (Option) 6. MC (1) receives the signal from lift arm angle sensor (12). MC (1) determines the stopping position of the lift arm (pre-selected by the operator) according to the signal of lift arm angle sensor (12).

Purpose: The lift arm height kickout control stops the lift arm as it is raising. It stops at any position - between where the lift arms are horizontal and fully raised - that has been preset by the operator. IMPORTANT: After replacing the lift arm angle sensor or Main Controller (MC), perform learning control of lift arm angle sensor (12) prior to performing work using Maintenance Pro Dr. (2). (Refer to TROUBLESHOOTING S/M T4-6.) Operation: 1. The lift arm height kickout control position (C) is set by lift arm auto leveler switch (height) (13), and is memorized in MC (1). Adjust the lift arm height kickout control to the required level. (Refer to the Operation and Maintenance Manual for the procedure.)

7. MC (1) disconnects the terminal #B-12 from the ground and deenergizes lift arm raising detent coil (7) on pilot valve (5). 8. Pilot pressure oil from loader pilot valve (5) shifts lift arm spool (9) of control valve (8) to the neutral position from what was previously the raise position. Then, the lift arm stops. 9. When lift arm auto leveler switch (height) (13) is turned OFF, the lift arm auto leveler height kickout control is deactivated.

fNOTE: When lift arm angle sensor (12) becomes

abnormal, the lift arm auto leveler height kickout control is deactivated.

2. MC (1) makes the lift arm auto leveler height kickout control effective when lift arm auto leveler switch (height) (13) is turned ON. 3. MC (1) connects the terminal #B-12 to the ground, and energizes lift arm raising coil (6) of pilot valve (5).

4. Pilot pressure oil is directed to lift arm spool (9) of control valve (8) to put it into the raise position and it holds it in this state as the lift arm is raised/and the detent function is applied at the control lever.

C B

5. Pressurized oil from the main pump is supplied to the bottom end of lift arm cylinder (10) and the lift arm continues to rise.

TNED-02-02-042 AB-

T2-2-72

Full Height Position of Lift Arm Horizontal Position of Lift Arm

C-

Setting Range of Lift Arm Stop (For Loading Range)

SECTION 2 SYSTEM Group 2 Control System

10 2 12

13 3

B-2

B-12

5 6

7 d

TNDF-02-02-044 a-

SET

1234-

MC MPDr. Information Controller CAN

5678-

Pilot Valve Lift Arm Raise Side Coil Lift Arm Lower Side Coil Control Valve

9- Lift Arm Spool 10- Lift Arm Cylinder 12- Lift Arm Angle Sensor

T2-2-73

OFF

From Fuse #16 in Fuse Box B

13- Lift Arm Auto Leveler Switch (Height)

SECTION 2 SYSTEM Group 2 Control System Lift Arm Auto Leveler Lower Kickout Control (Option) 6. MC (1) receives the signal from lift arm angle sensor (12). MC (1) determines the stopping position of the lift arm (pre-selected by the operator) according to the signal of lift arm angle sensor (12).

Purpose: The lift arm lower kickout control stops the lift arm as it is lowering. It stops at any position - between where the lift arms are horizontal and fully lowered - that has been preset by the operator.

7. MC (1) disconnects the terminal #B-2 from the ground and deenergizes lift arm lower detent coil (7) on pilot valve (5).

IMPORTANT: After replacing the lift arm angle sensor or Main Controller (MC), perform learning control of lift arm angle sensor (12) prior to performing work using Maintenance Pro Dr. (2). (Refer to TROUBLESHOOTING S/M T4-6.) Operation: 1. The lift arm lower kickout control position (C) is set by lift arm auto leveler switch (lower) (13), and is memorized in MC (1). Adjust the lift arm lower kickout control to the required level. (Refer to the Operation and Maintenance Manual for the procedure.)

8. Pilot pressure oil from loader pilot valve (5) shifts lift arm spool (9) of control valve (8) to the neutral position from what was previously the lower position. Then, the lift arm stops. 9. When lift arm auto leveler switch (lower) (13) is turned OFF, the lift arm auto leveler lower kickout control is deactivated.

fNOTE: Although terminal #B-2 is disconnected from

the ground in MC (1), it is connected to the ground when a fixed time has passed. Therefore, lift arm lower side coil (7) of pilot valve (5) is excited again and the lift arm float control becomes effective. (Refer to Lift Arm Float Control.)

2. MC (1) makes the lift arm auto leveler lower kickout control effective when lift arm auto leveler switch (lower) (13) is turned ON. 3. MC (1) connects the terminal #B-2 to the ground, and energizes lift arm lowering coil (7) of pilot valve (5).

fNOTE: When lift arm angle sensor (12) becomes

abnormal, the lift arm auto leveler lower kickout control is deactivated.

4. Pilot pressure oil is directed to lift arm spool (9) of control valve (8) to put it into the lower position and it holds it in this state as the lift arm is lowered/and the detent function is applied at the control lever. 5. Pressurized oil from the main pump is supplied to the rod end of lift arm cylinder (10) and the lift arm continues to lower.

B C

A TNED-02-02-043 AB-

T2-2-74

Lowered Position of Lift Arm Horizontal Position of Lift Arm

C-

Setting Range of Lift Arm Stop (For Return To Dig Position)

SECTION 2 SYSTEM Group 2 Control System

10 2 12

13 3

B-2

B-12

5 6

7 d

TNDF-02-02-045 a-

SET

1234-

MC MPDr. Information Controller CAN

5678-

Pilot Valve Lift Arm Raise Side Coil Lift Arm Lower Side Coil Control Valve

9- Lift Arm Spool 10- Lift Arm Cylinder 12- Lift Arm Angle Sensor

T2-2-75

OFF

From Fuse #16 in Fuse Box B

13- Lift Arm Auto Leveler Switch (Lower)

SECTION 2 SYSTEM Group 2 Control System Auto Idling Stop Control (Not used) Purpose: The auto idling stop control automatically stops the engine to reduce fuel consumption when the machine is not operated within a fixed time frame.

fNOTE: The auto idling stop control can be adjusted or turned ON/OFF with MPDr. (5).

fNOTE: After it shuts down, return key switch (43) to the

Operation: 1. When all of the following items under the topic of "Conditions" exist, MC (1) sends the auto idling stop signal to monitor controller (9) via Controller Area Network (CAN) communication (5). 1. When all following conditions exist, MC (1) blinks the light of auto idling stop switch (49) before 30 seconds for the auto idling stop enable time set by MPDr. (5). 2. MC (1) sends the buzzer signal to column display controller (2) by using CAN communication (12) and sounds buzzer (48) once. Then, MC (1) sounds buzzer (48) continuously before 15 seconds (intermittent sound 1) and 5 seconds (intermittent sound 2). 3. MC (1) turns auto idling stop relay (50) ON after the auto idling stop set time is over. 4. Therefore, the battery relay is turned OFF and the engine stops. (Refer to SYSTEM / Electrical System.) Conditions:  Accelerator Pedal (39): Not depressed  Parking Brake: In Operation  Brake Pedal (16): Not applied (Reference: Brake pedal angle conversion value: Less than 10 %)  Forward/Reverse Lever (20) or Switch (21) (Option): Neutral Position (c)  Front Attachment, Steering: Not operated (Reference: Pressure Sensor (Front Attachment Pressure) (29): 1.2 MPa, 122 kgf/cm2, 174 psi or less)  Auto Idling Stop: Effective and ON  Coolant Temperature Sensor (37): 100 °C (212 °F) or less  HST Oil Temperature Sensor (41): 100 °C (212 °F) or less  Abnormal communication: None  Engine Speed: 850 min-1 or less  Except during exhaust filter manual regeneration  Matching control: Activated  Auto-warming up control: Deactivated

T2-2-76

OFF or ACC position and restart the engine as is normally done.

SECTION 2 SYSTEM Group 2 Control System

39 40 48

17 18

43 3

20, 21

22 12 29 50

30 38

37 36

35 9

13 14

TNDF-02-02-036

Forward Position

1234567891011-

MC Column Display Controller Monitor Information Controller MPDr. Air Conditioner Controller HST Controller HST Motor 2 HST Motor 1 Transmission Parking Brake

12131415161718-

Reverse Position

CAN Communication HST Pump/4-Gear Pump Unit Engine ECM Brake Pedal Brake Angle Sensor Pressure Sensor (Front Attachment Pressure) 20- Forward/Reverse Lever 21- Forward/Reverse Switch (Option)

Neutral Position

22- Forward/Reverse Selector Switch (Option) 28- Pressure Sensor (Parking Brake) 29- Parking Brake Switch 30- Parking Brake Solenoid Valve 35- Crank Speed Sensor 36- Cam Angle Sensor 37- Coolant Temperature Sensor 38- Boost Temperature Sensor 39- Accelerator Pedal

T2-2-77

404143444849-

Accelerator Pedal Sensor HST Oil Temperature Sensor Key Switch Power Mode Switch Buzzer Auto Idling Stop Switch (Not used) 50- Auto Idling Stop Relay (Not used)

SECTION 2 SYSTEM Group 2 Control System Secondary Steering Control (Option) Normal operation: 1. MC (1) receives the signal from steering pressure switch (49). (Refer to Low Steering Oil Pressure Indicator Control.)

Purpose: The secondary steering is used to steer the machine in the event that the engine stops running. The secondary steering control uses an electric motor to drive an auxiliary pump to provide oil to steer the machine. Automatic operation check when the engine starts 1. In the event of low steering pressure, Main Controller (MC) (1) receives a signal from secondary steering pump delivery pressure sensor (48). 2. 3~30 seconds after the engine starts depending on the Hydrostatic Transmission (HST) oil temperature, MC (1) automatically turns secondary steering pump relay (52) ON for a maximum of 5 seconds. Then, MC (1) activates secondary steering motor (53). 3. Therefore, secondary steering pump (54) operates for a maximum of 5 seconds.

2. HST controller (7) receives signals from machine speed 1 sensor (23) and machine speed 2 sensor (24). HST controller (7) sends a signal to MC (1) via CAN communication (12). 3. If the steering cannot be operated, MC (1) activates secondary steering motor (53) to turn and operates secondary steering pump (54) ON for 60 seconds. The machine speed must be at or over 5 Km/h (3.1 mph) to operate (If it is not at or above this pressure, steering pressure switch (49) turns OFF). 4. Pressurized oil from secondary steering pump (54) is supplied to the steering circuit and makes the steering operation possible for 60 seconds. 5. While the above items are occurring, MC (1) sends the signals to column display controller (2) via CAN communication (12).

4. MC (1) turns secondary steering pump relay (52) OFF when secondary steering pump delivery pressure rises above 4.8 MPa (49 kgf/cm2, 696 psi) or more (normal pressure range) with secondary steering pump (54) operating.

6. Column display controller (2) lights secondary steering indicator (22) to indicate that the secondary steering is operating.

5. Column display controller (2) blinks secondary steering indicator (51) when secondary steering pump (54) delivery pressure is abnormally low.

fNOTE: The secondary steering pump (54) operation can be checked manually by operating secondary steering check switch (50) (option). IMPORTANT: Large amount of electricity is required to operate secondary steering pump (54). Refer to Operation and Maintenance Manual for this check switch.

T2-2-78

SECTION 2 SYSTEM Group 2 Control System

39 40 41 48 49

51 5

43 3

12 52

38 37 36 35

8 10

TNDF-02-02-037

To Steering Valve

1234567891011-

MC Column Display Controller Monitor Information Controller MPDr. Air Conditioner Controller HST Controller HST Motor 2 HST Motor 1 Transmission Parking Brake

1213141523243536373839-

CAN Communication HST Pump/4-Gear Pump Unit Engine ECM Machine Speed 1 Sensor Machine Speed 2 Sensor Crank Speed Sensor Cam Angle Sensor Coolant Temperature Sensor Boost Temperature Sensor Accelerator Pedal

40414348-

Accelerator Pedal Sensor HST Oil Temperature Sensor Key Switch Secondary Steering Pump Delivery Pressure Sensor (OPT) 49- Steering Pressure Switch (OPT) 50- Secondary Steering Operation Check Switch (OPT) 51- Secondary Steering Indicator (OPT)

T2-2-79

52- Secondary Steering Pump Relay (OPT) 53- Secondary Steering Motor (OPT) 54- Secondary Steering Pump (OPT)

SECTION 2 SYSTEM Group 2 Control System (Blank)

T2-2-80

SECTION 2 SYSTEM Group 2 Control System Control by Electric and Hydraulic Combined Circuit Electric and hydraulic combined circuit has the following controls.  Bucket Auto Leveler Control  Lift Arm Float Control  Lift Arm Kickout Control

T2-2-81

SECTION 2 SYSTEM Group 2 Control System Bucket Auto Leveler Control Purpose: The bucket auto leveler control automatically levels the bucket horizontal to start digging in a pile, and permits bucket roll back while engaging the pile and filling the bucket. Operation: 1. Bar (3) is located to the front of bucket proximity switch (2) while dumping the bucket. When the bucket control lever is moved from the dump position (bar 3 is close to the proximity switch while dumping) to the level position by tilting it back (roll back), bar (3) moves past the bucket proximity switch (2). 2. With bar (3) in front of the bucket proximity switch (2), the electrical detent circuit is energized by current (a) from fuse #16 in fuse box B. Note that proximity switch (2) detects the position of the bar, turns ON bucket leveler relay (12), and turns ON electromagnet (5) in pilot control valve (4) when the bar is close to it. 3. When the bucket control lever is moved farther than the bucket tilting detent position (position to move farther than the tilting position), the bucket control lever is held by electromagnet (5) on the bucket roll back side, and pressurized oil from pilot valve (4) moves bucket spool (9) in control valve (7). 4. Pressurized oil from main pump (10) flows to bucket cylinder (1) through bucket spool (9) in control valve (7) and tilts the bucket. 5. When bar (3) is moved away from bucket proximity switch (2), bucket proximity switch (2) turns OFF. Electromagnet (5) on the bucket roll back side turns OFF. 6. The bucket control lever returns to the neutral position (c). As bucket spool (9) in control valve (7) also returns to neutral position (c), bucket cylinder (1) stops. 7. This automatically permits the bucket to be leveled.

T2-2-82

SECTION 2 SYSTEM Group 2 Control System

12 c

TNDF-02-02-060

From Fuse Box B (Fuse #16)

Bucket Tilting Position

Neutral Position

123-

Bucket Cylinder Bucket Proximity Switch Bar

Pilot Valve (Bucket Control Lever) Electromagnet on Bucket Roll Back Side

6789-

Pilot Pump Control Valve Lift Arm Spool Bucket Spool

T2-2-83

10- Main Pump 11- Hydraulic Oil Tank 12- Bucket Leveler Relay

SECTION 2 SYSTEM Group 2 Control System Lift Arm Float Control Purpose: Permits floating up and down movement of the lift arm in response to the ground level external loads for snow removing and road cleaning Operation: 1. When the lift arm control lever is moved to the floating position (farther position than the lift arm lower position), the lift arm control lever is held by electromagnet (2) on the lift arm lowering side.

fNOTE: Electromagnet (2) on the lift arm lower side is always excited by current from fuse #16 in fuse box B with the key ON. 2. Pressurized oil from pilot valve (3) moves lift arm spool (8) in control valve (7) to the float position (farthest down position) (b).

3. Pressurized oil from main pump (10) flows to the neutral circuit through lift arm spool (8). In addition, the circuits on bottom and rod sides in lift arm cylinder (1) are connected in lift arm spool (8). Then, it is connected to hydraulic oil tank (11). 4. Therefore, as the circuit is opened between lift arm cylinder (1) and hydraulic oil tank (11), the lift arm can move freely up and down depending on the external forces on the lift arm. 5. The lift arm control lever returns to neutral position (c) if pulled more strongly than the magnetic force of electromagnet (2) on the lift arm lower side. 6. Therefore, lift arm spool (8) in control valve (7) returns to the neutral position and the lift arm float control is deactivated.

T2-2-84

SECTION 2 SYSTEM Group 2 Control System 1

7 c

2 6

11 10

From Fuse Box B (Fuse #16)

Lift Arm Float Position

Neutral Position

12-

Lift Arm Cylinder Electromagnet on Lift Arm Lowering Side

Pilot Valve (Lift Arm Control Lever) Pilot Pump

789-

Control Valve Lift Arm Spool Bucket Spool

T2-2-85

TNDF-02-02-061

10- Main Pump 11- Hydraulic Oil Tank

SECTION 2 SYSTEM Group 2 Control System Lift Arm Kickout Control Purpose: The lift arm lift kickout control raises and automatically stops the lift arm to the highest position. Operation: 1. Plate (3) is located in front of lift arm proximity switch (2) during lower operation of the lift arm. While plate (3) passes by lift arm proximity switch (2), lift arm proximity switch (2) is turned ON. 2. Therefore, lift arm kickout relay (12) is turned ON. Coil (5) on the lift arm raise side of pilot valve (4) is excited by current (a) from fuse #16 in fuse box B. 3. When the lift arm control lever is moved farther than the lift arm raise detent position (position to move farther than the raise position), the lift arm control lever is held by coil (5) on the lift arm raise side and pressure oil from pilot valve (4) moves lift arm spool (9) in control valve (7). 4. Pressure oil from main pump (10) flows to the bottom side of lift arm cylinder (1) through lift arm spool (8) in control valve (7) and raises the lift arm. 5. At the same time, plate (3) passes by lift arm proximity switch (2). When plate (3) becomes distant from lift arm proximity switch (2), lift arm proximity switch (2) is turned OFF and lift arm kickout relay (12) is turned OFF. Therefore, coil (5) on the lift arm raise side of pilot valve (4) is turned OFF. 6. Therefore, the lift arm control lever is returned to neutral position (c). As lift arm spool (8) in control valve (7) also returns to neutral position (c), lift arm cylinder (1) stops. 7. Consequently, the lift arm raising operation is stopped automatically.

T2-2-86

SECTION 2 SYSTEM Group 2 Control System

8 5 c

From Fuse Box B (Fuse #16)

Lift Arm Raise Position

Neutral Position

123-

Lift Arm Cylinder Lift Arm Proximity Switch Plate

Pilot Valve (Lift Arm Control Lever) Electromagnet on Lift Arm Raising Side

6789-

Pilot Pump Control Valve Lift Arm Spool Bucket Spool

T2-2-87

TNDF-02-02-065

10- Main Pump 11- Hydraulic Oil Tank 12- Lift Arm Kickout Relay

SECTION 2 SYSTEM Group 2 Control System (Blank)

T2-2-88

SECTION 2 SYSTEM Group 3 ECM System Outline Engine Control Module (ECM) (19) receives the signals from the sensors and Main Controller (MC) (30). ECM (19) processes and activates two-way valve (20), suction control valve (26), and Exhaust Gas Recirculation (EGR) motor (16) in order to control supply pump (24), injector (21), and the EGR valve.

Supply pump (24) is activated by the engine and produces high-pressure fuel. Common rail (23) distributes this high-pressure fuel produced by supply pump (24) to injector (21) for each engine cylinder to inject the fuel to power the engine.

12 13 14 15 16

31 17 30

24 25 TNDF-02-03-023

123456-

Fuel Filter Differential Pressure Sensor Atmospheric Pressure Sensor Intake-Air Temperature Sensor MAF (Mass Air Flow) Sensor Exhaust Filter Differential Pressure Sensor DOC (Diesel Oxidation Catalyst) Exhaust Temperature Sensor DPF (Diesel Particulate Filter) Exhaust Temperature Sensor

891011121314-

Crank Revolution Sensor Cam Angle Sensor Coolant Temperature Sensor Boost Pressure Sensor Boost Temperature Sensor Engine Oil Pressure Sensor Intake Manifold Temperature Sensor 15- EGR (Exhaust Gas Recirculation) Motor Position Sensor 16- EGR Motor

171819202122232425262728-

T2-3-1

Intake Throttle Position Sensor Intake Throttle Engine Control Module (ECM) Two-Way Valve Injector Common Rail Pressure Sensor Common Rail Supply Pump Fuel Tank Suction Control Valve Fuel Temperature Sensor CAN (Controller Area Network)

30- MC (Main Controller) 31- VGS (Variable Geometry System) Controller 32- VGS Actuator 33- HST (Hydrostatic Transmission) Controller)

SECTION 2 SYSTEM Group 3 ECM System Fuel Injection Control Engine Control Module (ECM) (19) monitors the engine operation status according to the signals from each sensor and Main Controller (MC) (30), and provides outputs for fuel injection amount rate, injection pressure, injection timing, and injection rate. The ECM uses two way valve (20) and suction control valve (26) to operate pressure and injection. Two-way valve (20) controls:  Fuel Injection Volume  Fuel Injection Timing  Fuel Injection Rate Suction control valve (26) controls:  Fuel Injection Pressure

T2-3-2

SECTION 2 SYSTEM Group 3 ECM System

13 14

17 30

19 18

24 25 TNDF-02-03-018

123456-

Fuel Filter Differential Pressure Sensor Atmospheric Pressure Sensor Intake-Air Temperature Sensor MAF Sensor Exhaust Filter Differential Pressure Sensor DOC Exhaust Temperature Sensor

7891011121314-

DPF Exhaust Temperature Sensor Crank Revolution Sensor Cam Angle Sensor Coolant Temperature Sensor Boost Pressure Sensor Boost Temperature Sensor Engine Oil Pressure Sensor Intake Manifold Temperature Sensor

15161718192021222324-

T2-3-3

EGR Motor Position Sensor EGR Motor Intake Throttle Position Sensor Intake Throttle ECM Two-Way Valve Injector Common Rail Pressure Sensor Common Rail Supply Pump

2526272830313233-

Fuel Tank Suction Control Valve Fuel Temperature Sensor CAN MC VGS Controller VGS Actuator HST Controller

SECTION 2 SYSTEM Group 3 ECM System Fuel Injection Volume Control Purpose: The fuel injection volume control provides the best fuel injection rate. Operation: 1. Engine Control Module (ECM) (19) reads the engine speed signals from crank revolution sensor (8) and cam angle sensor (9). 2. Main Controller (MC) (34) calculates the target engine speed according to the signals from accelerator pedal sensor (40), various sensors, switches, and Hydrostatic Transmission (HST) controller (29) via Controller Area Network (CAN) communication (28), and sends the signals equivalent to it to ECM (19) via CAN communication (28). (Refer to SYSTEM / Control System.) 3. ECM (19) mainly controls the fuel injection volume by turning two-way valve (20) in injector (21) ON or OFF according to the engine speed and the signals from MC (34).

T2-3-4

SECTION 2 SYSTEM Group 3 ECM System 6

50 49 48 47 46 45 44

12 13

14 15

30 43 17 19

29 42

39 38

27 26 23

36 35

34 24

25 TNDF-02-03-003

Fuel Filter Differential Pressure Sensor 2- Atmospheric Pressure Sensor 3- Intake-Air Temperature Sensor 4- MAF Sensor 5- Exhaust Filter Differential Pressure Sensor 6- DOC Exhaust Temperature Sensor 7- DPF Exhaust Temperature Sensor 8- Crank Revolution Sensor 9- Cam Angle Sensor 10- Coolant Temperature Sensor 11- Boost Pressure Sensor

12- Boost Temperature Sensor 13- Engine Oil Pressure Sensor 14- Intake Manifold Temperature Sensor 15- EGR Motor Position Sensor 16- EGR Motor 17- Intake Throttle Position Sensor 18- Intake Throttle 19- ECM 20- Two-Way Valve 21- Injector 22- Common Rail Pressure Sensor 23- Common Rail 24- Supply Pump 25- Fuel Tank

262728293031323334353637383940-

T2-3-5

Suction Control Valve Fuel Temperature Sensor CAN HST Controller VGS Controller VGS Actuator Information Controller Column Display Controller MC Traction Control Switch Power Mode Switch Key Switch 1st Speed Limit Switch HST Oil Temperature Sensor Accelerator Pedal Sensor

41- Forward/Reverse Selector Switch (Option) 42- Forward/Reverse Lever / Forward/Reverse Switch (Option) 43- Shift Lever 44- Machine Speed 1 Sensor 45- Machine Speed 2 Sensor 46- HST Circuit Pressure 1 Sensor 47- HST Circuit Pressure 2 Sensor 48- Pressure Sensor (Front Attachment Pressure) 49- Brake Angle Sensor 50- Pressure Sensor (Parking Brake)

SECTION 2 SYSTEM Group 3 ECM System Fuel Injection Pressure Control Purpose: The fuel injection pressure control controls the best fuel injection pressure. Operation: 1. Engine Control Module (ECM) (19) calculates the required fuel injection volume according to the engine speed and the signals from MC (34).(Refer to Fuel Injection Volume Control.) 2. Common rail pressure sensor (22) sends the signals according to the pressure in common rail (23) to ECM (19). 3. ECM (19) calculates the best fuel pressure for common rail (23) from the engine speed, fuel injection volume, and common rail pressure sensor (22) signal. 4. ECM (19) sends a signal to suction control valve (26) in supply pump (24) and supplies fuel at the rate of optimum pressure and volume within common rail (23). 5. Pressurized fuel in common rail (23) is supplied to injector (21), and this controls the fuel injection pressure.

T2-3-6

SECTION 2 SYSTEM Group 3 ECM System 6

50 49 48 47 46 45 44

12 13

14 15

30 43 17 19

29 42

39 38

27 26 23

36 35

34 24

25 TNDF-02-03-004

262728293031323334353637383940-

T2-3-7

SECTION 2 SYSTEM Group 3 ECM System Operation of Fuel Injection

Fuel Injection Timing Control

1. Fuel pressure from the common rail is always applied at nozzle (6) in the injector.

Purpose: The fuel injection timing control calculates the best fuel injection timing. Operation: 1. Engine Control Module (ECM) (19) calculates the fuel injection timing according to the engine speed and fuel injection volume. 2. ECM turns two-way valve (2) in the injector ON/OFF according to fuel injection timing. Fuel Injection Rate Control Purpose: The fuel injection rate control improves combustion in the engine cylinder.

2. When turning ON electromagnetic coil (9) in twoway valve (2), the high-pressure fuel in control chamber (5) returns to the fuel tank through orifice A (4). 3. This raises hydraulic piston (10) and causes nozzle (6) to open and start injection. 4. When turning OFF electromagnetic coil (9) in twoway valve (2), valve (8) is closed and the circuit to the fuel tank is closed. High-pressure fuel from the common rail flows to control chamber (5) through orifice B (12). 5. High-pressure fuel flows to control chamber (5), and hydraulic piston (10) is lowered by the pressure difference due to movement of hydraulic piston (10). This closes nozzle (6) and fuel injection stops.

Operation: 1. The injector first injects a small amount of fuel (known as pilot injection) which ignites. 2. After pilot injection and preliminary flame, the injector injects fuel through this flame multiple times, depending on operation requirements (main injection). 3. ECM controls the fuel injection timing and fuel injection volume by turning two-way valve (2) in the injector ON/OFF.

T2-3-8

SECTION 2 SYSTEM Group 3 ECM System 1. Two-way valve: ON

2. Injection Start 1

1 9

8 7

4 5 10 11

TDAA-02-03-014

TDAA-02-03-015

3. Two-way valve: OFF

4. Injection Stop 1

1 2

8 7

7 5

TDAA-02-03-017

TDAA-02-03-016

123-

From ECM Two-Way Valve Returning to Fuel Tank

456-

Orifice A Control Chamber Nozzle

789-

T2-3-9

From Common Rail Valve Electromagnetic Coil

10- Hydraulic Piston 11- Spring 12- Orifice B

SECTION 2 SYSTEM Group 3 ECM System Fuel Injection Volume Correction Control Purpose: The fuel injection volume correction control corrects fuel injection volume to the best fuel injection timing and volume. 1. When the engine starts and the engine speed is lower than the engine start correction speed, Engine Control Module (ECM) (19) corrects fuel injection volume. (Start up correction) 2. ECM (19) also compensates fuel injection volume according to the signals from atmospheric pressure sensor (2). (High altitude correction) 3. ECM (19) sends a signal to the injection solenoid coil at two-way valve (20) in injector (21) and optimizes the best fuel injection volume.

T2-3-10

SECTION 2 SYSTEM Group 3 ECM System

13 14

17 30

19 18

24 25

TNDF-02-03-019 123456-

Fuel Filter Differential Pressure Sensor Atmospheric Pressure Sensor Intake-Air Temperature Sensor MAF Sensor Exhaust Filter Differential Pressure Sensor DOC Exhaust Temperature Sensor

7891011121314-

15161718192021222324-

T2-3-11

EGR Motor Position Sensor EGR Motor Intake Throttle Position Sensor Intake Throttle ECM Two-Way Valve Injector Common Rail Pressure Sensor Common Rail Supply Pump

2526272830313233-

Fuel Tank Suction Control Valve Fuel Temperature Sensor CAN MC VGS Controller VGS Actuator HST Controller

SECTION 2 SYSTEM Group 3 ECM System EGR Control Purpose: The Exhaust Gas Recirculation (EGR) control re-circulates a part of exhaust gas to intake manifold (12) and combines it with intake-air. This lowers the cylinder combustion temperature and reduces the level of oxide of nitrogen (NOx).

fNOTE: The MAF (Mass Air Flow) sensor integrates

Operation:  EGR Gas Volume Control 1. Engine Control Module (ECM) (13) determines the EGR gas volume according to engine RPM's (min-1), fuel flow rate, intake manifold temperature, coolant temperature, atmospheric pressure, and intake-air temperature. 2. ECM (13) sends an output signal to EGR motor (10) to open EGR valve (8). This diverts a small amount of EGR gas to intake manifold (12) to blend with intake-air. 3. At the same time, ECM (13) senses the size of the opening amount of EGR valve (8) by using EGR motor position sensor (9).  EGR Gas Cooling 1. EGR gas is cooled by cooling system (6) in the EGR gas passage. 2. This cooled EGR gas is combined with intake-air to lower the combustion temperature in the cylinder, and NOx emissions are reduced.

T2-3-12

an intake-air temperature sensor. The MAF sensor reads intake-air flow from the air cleaner and the air temperature. Air flow will cool the heated sensor wire, and change the resistance, providing a signal to indicate air volume.  When intake the air temperature is cold, the resistance is high.  When intake the air temperature is hot, the resistance is low.

SECTION 2 SYSTEM Group 3 ECM System

5 6 4 7 8 12 9 11

14 15

20 19 18 17 16

TDAA-02-03-020 123456-

From Air Cleaner To Intercooler Exhaust Engine Outlet of Coolant Cooling System

7891011-

Inlet of Coolant EGR Valve EGR Motor Position Sensor EGR Motor Intake-Air (From Suction Intercooler)

12131415-

T2-3-13

Intake Manifold ECM Atmospheric Pressure Sensor MAF Sensor (Intake-Air Temperature Sensor)

16- Intake Manifold Temperature Sensor 17- Common Rail Pressure Sensor 18- Coolant Temperature Sensor 19- Cam Angle Sensor 20- Crank Revolution Sensor

SECTION 2 SYSTEM Group 3 ECM System Preheating Control

Purpose: The cylinder preheat system controls glow plugs which allows easier cold weather starting, and reduces white smoke and noise at start up. And it adjusts length of time the glow plugs are used to stabilize engine idle after start up.

Operation: 1. Engine Control Module (ECM) (3) receives input signals from intake-air temperature sensor (1) and coolant temperature sensor (2).

2. When the key switch is set to the ON position, current from terminal M (4) in the key switch flows to glow plug relay (7).

3. ECM (3) connects the ground circuit to energize glow plug relay (7) according to signals from intakeair temperature sensor (1) and coolant temperature sensor (2) and controls the length of time that glow plug relay (7) heats glow plug (8).

8 TDAA-02-03-010

1234-

T2-3-14

Intake-Air Temperature Sensor Coolant Temperature Sensor ECM From Key Switch Terminal M

5678-

Fuse Box From Battery (+24 VDC source) Glow Plug Relay Glow Plug

SECTION 2 SYSTEM Group 3 ECM System Alarm Control 14

Operation: 1. Engine Control Module (ECM) (5) receives the signals from engine oil pressure sensor (3), boost temperature sensor (2), fuel temperature sensor (4), Diesel Particulate Filter (DPF) exhaust temperature sensor (9), coolant temperature sensor (10), and fuel filter differential pressure sensor (1). 2. ECM (5) responds to the above sensor inputs, and sends an output signal to information controller (7) via Controller Area Network (CAN) communication (6).

3. Information controller (7) sends the digital signals to column display controller (8). Column display controller (8) lights the indicators.

12 11 10

MNDB-01-008

 Engine Warning Indicator (10)  Overheat Indicator (11)  Engine Oil Pressure Indicator (12)  Fuel Filter Restriction Indicator (13)  Exhaust Filter Alarm (red) / Exhaust Filter Regeneration Request (yellow) (14)  Service Indicator (15)

2 3 4 6 5

TNDF-02-03-035 12-

Fuel Filter Differential Pressure Sensor Boost Temperature Sensor

345-

Engine Oil Pressure Sensor Fuel Temperature Sensor ECM

678-

T2-3-15

CAN Information Controller Column Display Controller

DPF Exhaust Temperature Sensor 10- Coolant Temperature Sensor

SECTION 2 SYSTEM Group 3 ECM System Exhaust Filter Outline

Exhaust filter (1) is equipped with three sensors: DOC exhaust temperature sensor (2), DPF exhaust temperature sensor (3), and differential pressure sensor (4). DOC exhaust temperature sensor (2) and DPF exhaust temperature sensor (3) measure the temperature before and after diesel oxidation catalyst (DOC) (8). The signals from these sensors are used to effectively control the catalytic functions of both DOC (8) and DPF filter (7). Differential pressure sensor (4) measures the differential pressure before and after DPF (7) and determines when DPF (7) is becoming clogged and will need to be cleaned.

Exhaust filter (1) removes particulate matter (PM) and other exhaust substances from the diesel engine exhausts. Exhaust filter (1) consists of diesel oxidation catalyst (DOC) (8), diesel particulate filter (DPF) (7), and silencer (6). DOC (8) oxidizes unburned fuel and raises exhaust temperature. DPF (7) traps PM in form of soot, then burns and removes the PM by using high-temperature exhaust gas with DOC (8). DPF(7) and DOC (8) operate at the same time and this burns the soot from DPF (7), resulting in a light oil-free ash remaining. After being cleaned many times the DPF will need to be removed for cleaning or replacement if it is not able to be cleaned.

4 3 2

Machine Front Side

6 7 8

12-

Exhaust Filter Diesel Oxidation Catalyst (DOC) Exhaust Temperature Sensor

34-

TNED-02-03-001

Diesel Particulate Filter (DPF) Exhaust Temperature Sensor Differential Pressure Sensor

567-

T2-3-16

Differential Pressure Check Port Silencer Diesel Particulate Filter (DPF)

Diesel Oxidation Catalyst (DOC)

SECTION 2 SYSTEM Group 3 ECM System Operation 1. Exhaust gas from the engine goes to diesel particulate filter (DPF) (2) through diesel oxidation catalyst (DOC) (1).

fNOTE: Diesel oxidation catalyst (DOC) (1) is used during the required service level cleaning (regeneration) of the exhaust filter.

2. Diesel Particulate Matter (PM) is filtered out of the exhaust gas by DPF (2) as the exhaust gas flows through it. 3. The filtered exhaust gas is exhausted through silencer (3) end of the filter. 4. This process traps the PM (soot) in DPF (2). 5. The PM (soot) must be removed through the DPF cleaning process (known as regeneration) and discharged as CO2. (Refer to Exhaust Filter Cleaning Control.)

Exhaust Filter Assembly 1

TDAA-02-03-012

Filtration

Soot deposits

Cleaning (Also known as "regeneration")

CO2

PM TDAA-02-03-006

Diesel Oxidation Catalyst (DOC)

23-

Diesel Particulate Filter (DPF) Silencer

T2-3-17

SECTION 2 SYSTEM Group 3 ECM System Exhaust Filter Regenerative Control The exhaust filter regeneration control burns off the Particulate Matter (PM or also known as "soot") which has deposited in Diesel Particulate Filter (DPF) (5) by using hot exhaust gas. This process is referred to as "regeneration" ("cleaning"). The regeneration of the exhaust filter consists of "Passive Regeneration" and "Active Regeneration". "Active Regeneration" is a form of required regeneration that starts automatically (auto regeneration) or initiated either by the operator (manual regeneration). (Refer to SYSTEM / Control System.)  Passive Regeneration (Self cleaning while in operation) 1. Passive regeneration (self cleaning) works by using normal high exhaust temperatures that come with medium to heavy workloads. This does not require diesel oxidation catalyst (DOC) (6) function. 2. A catalyst is more activated in case the exhaust temperature at the inlet of DPF (5) is higher, increasing regeneration amount.

Auto Regeneration (Automatic Cleaning):  Required Auto-regeneration is automatically done 8 hours from the last regeneration. (Timed Regeneration)  A required Auto-regeneration is done when the pressure differential sensor (4) indicates that the pressure difference between the front and back of the DPF (5) has exceeded acceptable limits prior to this 8 hour time frame. (Pressure Differential Regeneration) Manual Regeneration: When the Exhaust Filter Regeneration Request is displayed on the monitor, the regeneration is manually done as follows:  Leave the accelerator pedal up (do not use throttle pedal),  Activate the control lever lock switch,  Place the forward/reverse lever in neutral,  Place the forward/reverse switch in neutral (option),  Applying the parking brake,  Press the exhaust filter regeneration switch

 Active Regeneration (Required cleaning) 1. Fuel is injected (post injection (11)) into the hot exhaust gas by diesel engine cylinder (7) and the exhaust gas mixed with unburned fuel is supplied to DOC (6). 2. DOC (6) oxidizes unburned fuel and raises DPF (5) temperature. 3. The exhaust temperature at the inlet side of DPF (5) increases to about 580 to 600 °C (1,075 to 1,100 °F) and DPF (5) is cleaned.

fNOTE: When the exhaust temperature before DPF (5)

is above 250 °C (480 °F) post injection (11) is used. When the exhaust temperature before DPF (5) is 250 °C (480 °F) or less, multi-injection of the engine cylinder diesel fuel injectors (10) is used and raises the exhaust temperature. Multi-injection (10) can be used only when the engine coolant temperature is 70 °C (160 °F) or more.

T2-3-18

SECTION 2 SYSTEM Group 3 ECM System

1 4 2

TDAA-02-03-013

TDAA-02-03-022

12-

ECM (Engine Control Module) DOC Exhaust Temperature Sensor

345-

DPF Exhaust Temperature Sensor Differential Pressure Sensor DPF (Diesel Particulate Filter)

678-

T2-3-19

DOC (Diesel Oxidation Catalyst) Cylinder Pilot Injection

9- Main Injection 10- Multi-Injection 11- Post Injection

SECTION 2 SYSTEM Group 3 ECM System Variable Turbocharger Control Purpose: The variable geometry turbocharger changes the nozzle opening inside of the turbine housing depending on the engine speed, engine load, and adjusts the inlet area of turbo. Therefore, the rotation speed of turbine is changed and the supercharging pressure is regulated as required for the engine. Consequently, a turbo effect can be obtained by supercharging the pressure efficiently even if the engine speed is at low idle. (Refer to Engine Manual.)

T2-3-20

SECTION 2 SYSTEM Group 4 Hydraulic System Outline Hydraulic system is broadly divided into the main circuit, steering circuit, pilot circuit, HST circuit, transmission circuit, and fan circuit. Main Circuit Power Source Main Pump

Controller Control Valve

Supplied to Lift Arm Cylinder, Bucket Cylinder

Steering Circuit Power Source Steering Pump Secondary Steering Pump (OPT)

Controller Priority Valve Steering Valve

Supplied to Steering Cylinder

Controller Brake Charge Valve Manifold Valve

Supplied to Charging Circuit Service Brake Circuit Parking Brake Circuit Front Attachment Operation Circuit Ride Control Circuit Exhaust Filter Regeneration Circuit Quick Coupler Circuit (OPT)

Controller Pump Displacement Angle Control Solenoid Valve Forward/Reverse Control Solenoid Valve

Supplied to HST Motor 1, HST Motor 2

Pilot Circuit Power Source Pilot Pump

HST Circuit Power Source HST Pump (HST Charging Pump)

Transmission Circuit Power Source Transmission Charge Pump

Controller Supplied to Clutch Pressure Control Solenoid Valve Clutch Circuit

Fan Circuit Power Source Pilot Pump

Controller Fan Valve

Supplied to Fan Motor

T2-4-1

SECTION 2 SYSTEM Group 4 Hydraulic System Main Circuit Outline: 1. Main pump (6) draws hydraulic oil from hydraulic oil tank (8) through suction filter (7) and delivers it. 2. The delivered pressurized oil flows to control valve (3). 3. Pressurized oil flowing to control valve (3) moves bucket cylinder (1) and lift arm cylinder (2) by shifting bucket spool (4) and lift arm spool (5). 4. Returning oil from bucket cylinder (1) and lift arm cylinder (2) returns to hydraulic oil tank (8) through control valve (3).

T2-4-2

SECTION 2 SYSTEM Group 4 Hydraulic System Standard Front Attachment 1

 Parallel Link Front Attachment 2

3 4

8 TNDF-02-04-104

From Priority Valve (Pressurized Oil from Steering Pump)

12-

Bucket Cylinder Lift Arm Cylinder

34-

Control Valve Bucket Spool

56-

T2-4-3

Lift Arm Spool Main Pump

78-

Suction Filter Hydraulic Oil Tank

SECTION 2 SYSTEM Group 4 Hydraulic System Neutral Circuit

Single Operation Circuit

 When the control lever is in neutral, pressurized oil from main pump (6) returns to hydraulic oil tank (8) through neutral circuit (9) of control valve (3).

 Pressurized oil from main pump (6) flows to lift arm spool (5) and bucket spool (4) through control valve (3).

Relief Circuit 1. Main relief valve (10) prevents the pressure in the circuit (between pump and control valve) from increasing over the set pressure while operating lift arm spool (5) and bucket spool (4). 2. When lift arm spool (5) and bucket spool (4) are in the neutral position, overload relief valve (11) prevents the pressure in the circuit (between control valve and actuator) due to the surge pressure developed by external force from increasing over the set pressure. 3. In addition, overload relief valve (11) is equipped with make-up function. It draws pressurized oil from hydraulic oil tank (8) and prevents cavitation from occurring when the pressure in the circuit (between control valve and actuator) decreases below the specified value. 4. Low-pressure relief valve (12) keeps the pressure in the circuit (between control valve and hydraulic oil tank) at the specified pressure and improves the actuator drawing operation when cavitation occurs.

T2-4-4

SECTION 2 SYSTEM Group 4 Hydraulic System

a b

c 11 2

12 10 8 6 TNDF-02-04-103 a-

Arm Roll-Out

Arm Tilt

123-

Bucket Cylinder Lift Arm Cylinder Control Valve

456-

Bucket Spool Lift Arm Spool Main Pump

8- Hydraulic Oil Tank 9- Neutral Circuit 10- Main Relief Valve

fNOTE: The illustration shows the oil flow when the front attachment control lever is in neutral (not operated) while the engine runs.

T2-4-5

Standard Front Attachment

Parallel Link Front Attachment

11- Overload Relief Valve 12- Low-Pressure Relief Valve

SECTION 2 SYSTEM Group 4 Hydraulic System Bucket Tilt Circuit (Parallel Link Front Attachment) 1. Pilot pressure oil (Pia2) shifts bucket spool (8) during the bucket tilt operation. 2. Pressurized oil from main pump (9) flows to bucket regenerative valve (3) through the bucket spool (8). 3. The circuit pressure is increased by orifice (4) and logic valve (5) is opened. 4. Pressurized oil flows to the bottom side of bucket cylinder (1) through logic valve (5) and tilts the bucket.

T2-4-6

SECTION 2 SYSTEM Group 4 Hydraulic System

2 1

6 8 Pia2

10 9

TNDF-02-04-101

Pia2- Bucket Tilt (Pilot Pressure)

123-

Bucket Cylinder Check Valve Bucket Regenerative Valve

456-

Orifice Logic Valve Pilot Check Valve

78-

T2-4-7

Bucket Regenerative Selector Valve Bucket Spool

9- Main Pump 10- Hydraulic Oil Tank

SECTION 2 SYSTEM Group 4 Hydraulic System Bucket Dump Circuit (Parallel Link Front Attachment) 1. Pilot pressure oil (Pib2) shifts bucket spool (8) and bucket regenerative selector valve (7) during the bucket dump operation. 2. Pressurized oil from main pump (9) flows to the bottom side of bucket cylinder (1) through bucket spool (8) and bucket regenerative valve (3) and dumps the bucket. 3. Returning oil from the rod side of bucket cylinder (1) flows to bucket regenerative valve (3). However, pressurized oil flows to bucket regenerative selector valve (7) preferentially due to orifice (4) of the return circuit through bucket regenerative valve (3). 4. Pressurized oil from bucket regenerative selector valve (7) flows to bucket regenerative valve (3), closes logic valve (5), and opens pilot check valve (6). 5. Returning oil from the rod side of bucket cylinder (1) flows through check valve (2) and pilot check valve (6) and is combined with pressurized oil from bucket spool (8). Combined pressurized oil is supplied to the bottom side of bucket cylinder (1) and increases bucket dump operating speed.

T2-4-8

SECTION 2 SYSTEM Group 4 Hydraulic System

2 1

6 8 Pib2

10 9

TNDF-02-04-101

Pib2- Bucket Dump (Pilot Pressure)

123-

Bucket Cylinder Check Valve Bucket Regenerative Valve

456-

Orifice Logic Valve Pilot Check Valve

78-

T2-4-9

Bucket Regenerative Selector Valve Bucket Spool

9- Main Pump 10- Hydraulic Oil Tank

SECTION 2 SYSTEM Group 4 Hydraulic System Combined Operation Circuit  Lift Arm Raise, Bucket Dump 1. When operating lift arm raise and bucket dump, pilot pressure oil (Pia1, Pib2) moves lift arm spool (5) and bucket spool (4). 2. Pressurized oil from main pump (6) flows to check valve (10) and lift arm spool (5) of control valve (3). Then, it moves lift arm cylinder (2) and raises the lift arm. 3. At the same time, pressurized oil from main pump (6) flows to bucket spool (4). Then, it moves bucket cylinder (1) and dumps the bucket. 4. Although lift arm raise operation is more heavily loaded than bucket dump operation, pressurized oil flowing through parallel circuit (12) flows to lift arm cylinder (2) preferentially according to the operation of bucket flow rate control valve (11) so that lift arm cylinder (2) moves smoothly.

T2-4-10

SECTION 2 SYSTEM Group 4 Hydraulic System

1 3

Pib2

11 2 5

Pia1

12 10

Pia1- Lift Arm Raise (Pilot Pressure Oil)

Pib2- Bucket Dump (Pilot Pressure Oil)

123-

456-

Bucket Cylinder Lift Arm Cylinder Control Valve

Bucket Spool Lift Arm Spool Main Pump

TNDF-02-04-014

8- Hydraulic Oil Tank 10- Check Valve 11- Bucket Flow Rate Control Valve

T2-4-11

12- Parallel Circuit

SECTION 2 SYSTEM Group 4 Hydraulic System Steering Circuit Outline 1. Steering pump (4) draws hydraulic oil from hydraulic oil tank (6) through suction filter (5) and delivers it. 2. The delivered pressurized oil is divided in priority valve (3). One flows to steering valve (2). The other flows to control valve (3) and is combined with pressurized oil from the main pump. (Refer to Main Circuit.) 3. Pressurized oil flowing to steering valve (2) moves steering cylinder (1) by shifting the steering valve spool. 4. Returning oil from steering cylinder (1) returns to hydraulic oil tank (6) through steering valve (2).

T2-4-12

SECTION 2 SYSTEM Group 4 Hydraulic System

5 TNDF-02-04-017

To Control Valve

12-

Steering Cylinder Steering Valve

34-

Priority Valve Steering Pump

56-

T2-4-13

Suction Filter Hydraulic Oil Tank

SECTION 2 SYSTEM Group 4 Hydraulic System Priority Valve Circuit (When steering is in neutral) 1. Priority spool (3) of priority valve (2) has moved left due to the spring force with the engine stopped.

fNOTE: The illustration on the right shows the oil flow

2. When the engine starts, pressurized oil from steering pump (1) flows to steering valve (7) through priority spool (3) of priority valve (2). 3. At the same time, pressurized oil from steering pump (1) also flows to priority spool circuits (LS1) and (LS2) through orifices (4, 5, 22). 4. When not operating steering wheel (14), pressurized oil from priority spool circuit (LS2) flows to hydraulic oil tank (20) through steering spool (8) of steering valve (7). Then, pressure in priority spool circuit (LS2) decreases. 5. As pressure in priority spool circuit (LS1) is higher than pressure in priority spool circuit (LS2) and the spring force, priority spool (3) moves right until port (CF) is closed. 6. Therefore, more pressurized oil from steering pump (1) is supplied to control valve (a) through priority spool (3) and port (EF). 7. The notch is located on priority spool (3).The delivery port in steering pump (1) is always connected to port (CF) and port (EF) through this notch. 8. Therefore, pressurized oil from port (CF) flows to priority spool circuits (LS1) and (LS2). 9. Pressurized oil which flows to priority spool circuit (LS2) is supplied to preheating circuit (24) in steering valve (7) through port (LS), warms steering valve (7), and prevents steering spool (8) from sticking.

T2-4-14

when not operating steering wheel (14).

SECTION 2 SYSTEM Group 4 Hydraulic System 12

11 18

9 14

21 8 7

15 19 17 23

a EF

5 4

LS1

LS2

20 TNDF-02-04-041

CF- Port CF LS1- Priority Spool Circuit LS- Port LS

LS2- Priority Spool Circuit EF- Port EF a- To Control Valve

123456-

78910-

Steering Pump Priority Valve Priority Spool Orifice 1 Orifice 2 Steering Relief Valve (Priority Valve)

Steering Valve Steering Spool Gerotor Overload Relief Valve (Steering) 11- Steering Accumulator 12- Steering Cylinder (Left)

13141517181920-

T2-4-15

Steering Cylinder (Right) Steering Wheel Check Valve Load Check Valve Make-Up Valve Orifice 1 (Variable) Hydraulic Oil Tank

21- Orifice 2 (Variable) 22- Orifice 3 23- Preheating Circuit

SECTION 2 SYSTEM Group 4 Hydraulic System Steering Circuit (When steering is operated) 1. When operating steering wheel (14), orifices (19, 21) between steering spool (8) and the sleeve of steering valve (7) are opened in proportion to the steering wheel (14) speed. Then, the oil passage between steering spool (8) and gerotor (9) is connected.

7. Gerotor (9) delivers pressurized oil as a hydraulic motor. This pressurized oil is combined with pressurized oil from orifice (21) and moves steering cylinders (12, 13) at right and left.

2. When operating steering wheel (14) quickly, orifices (19, 21) are opened widely and more pressurized oil flows to gerotor (9) and steering cylinders (12, 13). On the contrary, when operating steering wheel (14) slowly, orifices (19, 21) are opened narrowly and less pressurized oil flows to gerotor (9) and steering cylinders (12, 13). 3. When operating steering wheel (14), orifices (19, 21) are opened at the same time. Then, pressurized oil from port (CF) and orifices (19, 21) of steering valve (7) flows to gerotor (9) and steering cylinders (12, 13). 4. When pressurized oil has flown to gerotor (9) and steering cylinders (12, 13), the pressure of priority spool circuit (LS1) and pressure between port (CF) of priority valve (2) and orifices (19, 21) of steering valve (7) decrease.

8. When steering wheel (14) is stopped, the oil passage between steering spool (8) and the sleeve is disconnected. Steering spool (8) and the sleeve are returned to the neutral position by the spring force completely. Pressurized oil (CF) from priority valve (2) does not flow to gerotor (9) and the steering cylinder is stopped.

fNOTE: The load sensing control is performed according to the combination of orifices (19, 21) and priority spool (3) of priority valve (2).

fNOTE: As gerotor (9) is connected to the intermediate

shaft of steering valve (7), the powered steering effect is generated.

fNOTE: The illustration on the left shows the oil flow when steering wheel (14) is rotated right.

fNOTE: Steering accumulator (11) reduces the joggling of the vehicle taking place when the steering handle operation is stopped.

5. Therefore, priority spool (3) of priority valve (2) moves left. 6. Priority spool (3) of priority valve (2) moves to the position where pressurized oil equivalent to the open amount of orifice (19) flows to steering valve (7).

T2-4-16

SECTION 2 SYSTEM Group 4 Hydraulic System 12

11 18

21 19 7

a EF

5 4

LS1

LS2

20 TNDF-02-04-044

CF- Port CF LS1- Priority Spool Circuit LS- Port LS

LS2- Priority Spool Circuit EF- Port EF a- To Control Valve

123456-

78910-

Steering Pump Priority Valve Priority Spool Orifice 1 Orifice 2 Steering Relief Valve (Priority Valve)

Steering Valve Steering Spool Gerotor Overload Relief Valve (Steering) 11- Steering Accumulator 12- Steering Cylinder (Left)

13141517181920-

T2-4-17

Steering Cylinder (Right) Steering Wheel Check Valve Load Check Valve Make-Up Valve Orifice 1 (Variable) Hydraulic Oil Tank

21- Orifice 2 (Variable) 22- Orifice 3

SECTION 2 SYSTEM Group 4 Hydraulic System Steering Stop Circuit (When steering cylinder is at stroke end) 1. Pressurized oil (CF) which flows from steering spool (8) to gerotor (9) is divided in steering spool (8), flows to port (LS) of priority valve (2), and is routed to priority spool circuit (LS2). 2. When steering cylinders (12, 13) at right and left reach the stroke end, the pressure in priority spool circuit (LS2) increases due to pressurized oil from port (LS). 3. When the pressure in priority spool circuit (LS2) increases over the specified value, steering relief valve (priority valve) (6) is activated and pressurized oil routed to priority spool circuit (LS2) flows to hydraulic oil tank (20) through steering relief valve (priority valve) (6). 4. When steering relief valve (priority valve) (6) is activated, pressurized oil in priority spool circuit (LS2) flows to hydraulic oil tank (20) and the pressure difference is generated between priority spool circuits (LS1) and (LS2) by orifice (5). 5. Therefore, priority spool (3) moves right. 6. Consequently, pressurized oil from priority valve (2) flows to control valve (a) through port (EF).

T2-4-18

SECTION 2 SYSTEM Group 4 Hydraulic System 12

11 18

21 19 7

a EF

5 4

LS1

LS2

20 TNDF-02-04-043

CF- Port CF LS1- Priority Spool Circuit LS- Port LS

LS2- Priority Spool Circuit EF- Port EF a- To Control Valve

123456-

78910-

Steering Pump Priority Valve Priority Spool Orifice 1 Orifice 2 Steering Relief Valve (Priority Valve)

Steering Valve Steering Spool Gerotor Overload Relief Valve (Steering) 11- Steering Accumulator 12- Steering Cylinder (Left)

13141517181920-

T2-4-19

Steering Cylinder (Right) Steering Wheel Check Valve Load Check Valve Make-Up Valve Orifice 1 (Variable) Hydraulic Oil Tank

21- Orifice 2 (Variable) 22- Orifice 3

SECTION 2 SYSTEM Group 4 Hydraulic System Secondary Steering Circuit (Option) 1. When the conditions for secondary steering control exist, MC activates secondary steering motor (3) so that secondary steering pump (5) is activated. (Refer to Control System / Secondary Steering Control.)

f NOTE: The secondary steering control makes the

f NOTE: Steering pressure switch (15) is turned OFF when the pressure in the steering circuit decreases below the specified value (the steering can not be operated). MC receives the OFF signal from steering pressure switch (15). This is one of the conditions for secondary steering control. 2. Secondary steering pump (5) draws hydraulic oil from hydraulic oil tank (4) and delivers it to steering valve (9) through load check valve (8) of secondary steering block (7).

f NOTE: Secondary steering pump delivery pressure

sensor (16) converts the pressure value in the secondary steering circuit into the signal and sends it to MC. MC judges the secondary steering control state, i. e. that secondary steering pump (5) is correctly operated. 3. Steering valve (9) moves steering cylinders (11, 12) at right and left by shifting steering spool (10) when operating steering wheel (13). (Refer to Steering Circuit.) 4. Load check valve (8) is installed so that pressurized oil from priority valve (2) may not be routed to secondary steering valve (5) in normal state. 5. Load check valve (14) is installed so that pressurized oil from secondary steering valve (5) may not flow back to the steering pump (1) side. 6. Relief valve (6) prevents the pressure in the circuit between secondary steering pump (5) and steering valve (9) from increasing over the set pressure when secondary steering pump (5) is operated.

T2-4-20

steering operation possible by using secondary steering pump (5) for a while (max. 60 seconds) when hydraulic pressure can not be supplied due to the engine fault or the steering can not be operated.

SECTION 2 SYSTEM Group 4 Hydraulic System 11

TNDF-02-04-012

12345-

Steering Pump Priority Valve Secondary Steering Motor Hydraulic Oil Tank Secondary Steering Pump

678910-

Relief Valve Secondary Steering Block Load Check Valve Steering Valve Steering Spool

1112131415-

T2-4-21

Steering Cylinder (Left) Steering Cylinder (Right) Steering Wheel Load Check Valve Steering Pressure Switch

16- Secondary Steering Pump Delivery Pressure Sensor

SECTION 2 SYSTEM Group 4 Hydraulic System Pilot Circuit Outline Pressurized oil from the pilot pump is used in order to operate the following circuits.  Charging Circuit  Service Brake Circuit  Parking Brake Circuit  Front Attachment Operation Circuit  Ride Control Circuit  Exhaust Filter Regeneration Circuit  Quick Coupler Circuit (Option)  Fan Circuit

T2-4-22

SECTION 2 SYSTEM Group 4 Hydraulic System 4

3 12

1 15 18 16

2 21

25 TNDF-02-04-001

1234567-

Charging Circuit Brake Charge Valve Manifold Valve Front Attachment Operation Circuit Lift Arm Pilot Valve Bucket Pilot Valve Auxiliary Pilot Valve (OPT)

89-

Multiple Control Valve Exhaust Filter Regeneration Control Solenoid Valve 10- Exhaust Filter Regeneration Circuit 11- Quick Coupler Solenoid Valve (OPT) 12- Ride Control Valve (OPT)

1314151617181920-

f NOTE: Refer to page T2-4-58 "Fan Circuit" for fan circuit (21).

T2-4-23

Ride Control Spool (OPT) Ride Control Circuit (OPT) Parking Brake Brake Valve Service Brake Service Brake Circuit Fan Valve Fan Motor

212223242526-

Fan Circuit Pilot Filter Pilot Pump Suction Filter Hydraulic Oil Tank Quick Coupler Circuit (OPT)

SECTION 2 SYSTEM Group 4 Hydraulic System Charging Circuit The charging circuit consists of brake charge valve (9) and manifold valve (4). It supplies pressurized oil from pilot pump (15) to service brake circuits (a, b) preferentially and also supplies pressurized oil to other circuits.

12. Therefore, pressurized oil from pilot pump (15) is also supplied to fan circuit (c) through priority valve (brake) (12). (Refer to Fan Circuit.)

fNOTE: Priority valve (brake) (12) is not closed

Operation: 1. When the engine starts, pressurized oil from pilot pump (15) is supplied to brake charge valve (9) through the pilot filter.

completely as the spring force is adjusted. When it is almost closed (moves to the right end), specified volume of pressurized oil is supplied to fan circuit (c). (To be continued to page T2-4-26.)

2. When the pressure of service brake accumulators (8,14) are less than the specified level, charge relief valve (10) is closed. 3. At this time, as the spring force of priority valve (brake) (12) and the pressure in port A becomes stronger than the pressure in port B, priority valve (brake) (12) moves to the right. 4. Therefore, pressurized oil flowing through priority valve (brake) (12) pushes to open check valve (11) and more pressurized oil flows to shuttle valve (13) so that it is accumulated in service brake accumulators (8, 14). 5. Shuttle valve (13) is shifted according to the pressure of service brake accumulators (8, 14) (front and rear). 6. Service brake accumulators (8, 14) accumulates pilot pressurized oil from shuttle valve (13) so that the pressure should be same. 7. The pressurized oil accumulated in service brake accumulators (8, 14) at the specified level is supplied to the brake valve in order to apply the brake. (Refer to Service Brake Circuit.) 8. At the same time, pressurized oil flowing through check valve (11) is supplied to manifold valve (4). Then, pressurized oil is supplied to other pilot circuits. 9. When the circuit pressure in brake charge valve (9) increases over the specified level, charge relief valve (10) is opened. 10. As port A in priority valve (brake) (12) is connected to the port in hydraulic oil tank (16), the pressure in port A decreases. 11. As the spring force of priority valve (brake) (12) and the pressure in port A becomes lower than the pressure in port B, priority valve (brake) (12) moves to the left.

T2-4-24

SECTION 2 SYSTEM Group 4 Hydraulic System 1

PS1

P DR

5 16

6 7

16 PP1

9 b

13 16 11

c A

abc-

To Service Brake Circuit (Front) To Service Brake Circuit (Rear) To Fan Circuit

BR- To Parking Brake Circuit PP1- To Front Attachment Operation Circuit

PS1- To Ride Control Circuit, Exhaust Filter Regeneration Circuit, and Quick Coupler Circuit (OPT)

Pilot Accumulator (Front Attachment) Reducing Valve Parking Brake Solenoid Valve Manifold Valve Parking Brake Accumulator

67-

1011121314-

2345-

89-

Check Valve Front Control Lever Lock Solenoid Valve Service Brake Accumulator (Rear) Brake Charge Valve

fNOTE: The illustration shows the oil flow when priority valve (brake) (12) moves to the right.

T2-4-25

Charge Relief Valve Check Valve Priority Valve (Brake) Shuttle Valve Service Brake Accumulator (Front)

TNDF-02-04-002

15- Pilot Pump 16- Hydraulic Oil Tank

SECTION 2 SYSTEM Group 4 Hydraulic System 13. Pressurized oil from brake charge valve (9) is supplied to port P in manifold valve (4). 14. Pressurized oil from port P is accumulated in pilot accumulator (front attachment) (1). In addition, it is supplied to parking brake accumulator (1) through reducing valve (2), port PS1, control lever lock solenoid valve (7), and check valve (6). 15. Pressurized oil from port PS1 is supplied to the pilot circuit in order to operate the spool in ride control valve and the exhaust filter/quick coupler spool in the multiple control valve. (Refer to Ride Control Circuit, Exhaust Filter Regeneration Circuit, and Quick Coupler Circuit (Option).) 16. Reducing valve (2) makes the pressure in port P decrease to the set pressure. (Refer to COMPONENT OPERATION / Manifold Valve.) 17. Pressurized oil from port PP1 is supplied to each pilot valve by shifting control lever lock solenoid valve (7) in order to operate the spool in the multiple control valve. (Refer to Front Attachment Operation Circuit.)

f NOTE: When control lever lock solenoid valve (7) is

closed, pressurized oil is not supplied to the pilot valve. This prevents an operating error. 18. The pressurized oil accumulated in parking brake accumulator (5) at the specified level is supplied to the parking brake through port BR by shifting parking brake solenoid valve (3) in order to release the parking brake. (Refer to Parking Brake Circuit.)

T2-4-26

SECTION 2 SYSTEM Group 4 Hydraulic System 1

PS1

P DR

5 16

6 7

16 PP1

9 b

13 16 11

c A

abc-

To Service Brake Circuit (Front) To Service Brake Circuit (Rear) To Fan Circuit

BR- To Parking Brake Circuit PP1- To Front Attachment Operation Circuit

PS1- To Ride Control Circuit, Exhaust Filter Regeneration Circuit, and Quick Coupler Circuit (OPT)

Pilot Accumulator (Front Attachment) Reducing Valve Parking Brake Solenoid Valve Manifold Valve Parking Brake Accumulator

67-

1011121314-

2345-

89-

Check Valve Control Lever Lock Solenoid Valve Service Brake Accumulator (Rear) Brake Charge Valve

fNOTE: The illustration shows the oil flow when priority valve (brake) (12) moves to the right.

T2-4-27

Charge Relief Valve Check Valve Priority Valve (Brake) Shuttle Valve Service Brake Accumulator (Front)

TNDF-02-04-002

15- Pilot Pump 16- Hydraulic Oil Tank

SECTION 2 SYSTEM Group 4 Hydraulic System Service Brake Circuit When the service brake is applied: 1. Pressurized oil from the brake charge valve (a, b) are routed to port PA and port PB in brake valve (1). (Refer to Charging Circuit.) 2. When brake pedal (2) is depressed, spools (3, 4) in brake valve (1) are moved according to brake pedal (2) application angle. (Refer to COMPONENT OPERATION / Brake Valve.)

When the service brake is released: 1. Pressurized oil (a, b) from the brake charge valve is blocked by spools (3, 4) in brake valve (1). 2. When brake pedal (2) is not applied, brake operating pressurized oil between port A and front brake (7) and port B and rear brake (9) returns to hydraulic oil tank (11) through spools (3, 4). 3. Therefore, front brake (7) and rear brake (9) are released.

3. Pilot pressurized oil according to brake pedal (2) application angle is supplied to front brake (7) and rear brake (9) through spools (3, 4) and orifice (6). 4. Therefore, front brake (7) and rear brake (9) are applied. 5. Pilot pressurized oil flowing through spools (3, 4) is routed in order to push spools (3, 4) back through orifice (6). 6. Therefore, the oil passages between port PA and port A and port PB and port B are blocked according to the movements of spools (3, 4). 7. The pressure in the brake output circuit is maintained, and the oil pressure in proportion to the brake pedal (2) application angle is output.

fNOTE: Front brake (7) and rear brake (9) are housed

in front axle (8) and rear axle (10) respectively. (Refer to COMPONENT OPERATION / Axle.)

fNOTE: The pressure in front axle (8) and rear axle (10)

are equal to the pressure in hydraulic tank (11) to prevent the brake from dragging.

fNOTE: As the movements of spools (3, 4) are equal

due to balance spring (5), the output pressure in port A becomes equal to the output pressure in port B.

fNOTE: The pressure in the service brake circuit can

be kept for a specified period of time due to the service brake accumulator and the check valve with the engine stopped

T2-4-28

SECTION 2 SYSTEM Group 4 Hydraulic System When brake is applied 1

3 PB

11 4

 When brake is released

TNDF-02-04-004

5 3 PA

4 PB

11 TNDF-02-04-003

From Brake Charge Valve

123-

Brake Valve Brake Pedal Spool

456-

Spool Balance Spring Orifice

789-

fNOTE: The illustration shows the oil flow when the brake is applied.

T2-4-29

Front Brake Front Axle Rear Brake

10- Rear Axle 11- Hydraulic Oil Tank

SECTION 2 SYSTEM Group 4 Hydraulic System Parking Brake Circuit 1. Pressurized oil (P) from the brake charge valve is routed to parking brake solenoid valve (7). (Refer to Charging Circuit.) 2. Parking brake solenoid valve (7) is turned ON and the spool is shifted when the parking brake switch is set to the OFF position. 3. Pilot pressurized oil flows through the spool in parking brake solenoid valve (7) and is routed to brake piston (1) in order to release the parking brake. 4. Therefore, spring (2) is pushed back and parking brake (3) is released. 5. Parking brake solenoid valve (7) is turned OFF and the spool is shifted when the parking brake switch is set to the ON position. 6. Pilot pressurized oil routed to brake piston (1) returns to hydraulic oil tank (8). 7. Therefore, brake piston (1) is pushed back by the spring (2) force and the parking brake is applied.

fNOTE: When the engine stops, pressurized oil (parking brake release pressure) from the pilot pump is not supplied and parking brake (3) can not be released.

fNOTE: When the engine stops and pressurized oil accumulated in parking brake accumulator (6) is remained, parking brake (3) can be released.

fNOTE: The transmission has built-in parking brake (3). (Refer to COMPONENT OPERATION / Transmission.)

T2-4-30

SECTION 2 SYSTEM Group 4 Hydraulic System

2 5 P

c b

7 3 8 TNDF-02-04-005

Pa-

From Brake Charge Valve Parking brake is released

Parking brake is applied

Signal from Parking Brake Switch

123-

Brake Piston Spring Parking Brake

567-

Manifold Valve Parking Brake Accumulator Parking Brake Solenoid Valve

Hydraulic Oil Tank

fNOTE: The illustration shows the oil flow when parking brake (3) is released.

T2-4-31

SECTION 2 SYSTEM Group 4 Hydraulic System Front Attachment Operation Circuit 1. Front control lever lock solenoid valve (5) is shifted when the front control lever lock switch is set to the OFF position. 2. Pressurized oil from port PP1 in brake charge valve (4) is routed to pilot valves (1, 2, 3). (Refer to Charging Circuit.) 3. Pilot pressurized oil in proportion to the operation of pilot valves (1, 2, 3) moves spools (7, 8, 9, 10) in multiple control valve (6). 4. Therefore, pressurized oil from main pump (12) flows through spools (7, 8, 9, 10) in multiple control valve (6) and moves the lift arm cylinder, the bucket cylinder, and other actuators. (Refer to Main Circuit.) 5. Slow return valve (11) is provided in the pilot circuit inlet at both sides of lift arm spool (10) and prevents lift arm spool (10) from moving quickly. (Refer to COMPONENT OPERATION / Control Valve.)

T2-4-32

SECTION 2 SYSTEM Group 4 Hydraulic System 1

6 3

7 18

8 20

13 b

PP1

9 14

10 16

13 ab-

From Brake Charge Valve Signal from Control Lever Lock Switch

cd-

Quick Coupler Circuit (OPT) Exhaust Filter Regeneration Circuit

12345-

Bucket Pilot Valve Lift Arm Pilot Valve Auxiliary Pilot Valve (OPT) Manifold Valve Control Lever Lock Solenoid Valve

67891011-

Multiple Control Valve Auxiliary 2 Spool (OPT) Auxiliary 1 Spool (OPT) Bucket Spool Lift Arm Spool Slow Return Valve

121314151617-

T2-4-33

Main Pump Hydraulic Oil Tank Bucket Roll Back Bucket Dump Lift Arm Raise Lift Arm Lower

18192021-

TNDF-02-04-006

Auxiliary (OPT) Auxiliary (OPT) Auxiliary (OPT) Auxiliary (OPT)

SECTION 2 SYSTEM Group 4 Hydraulic System Ride Control Circuit  Accumulating ride control accumulator (2) 1. Pressurized oil from the main pump moves lift arm cylinder (4) by lift arm spool (9) operation. (Refer to Main Circuit / Lift Arm, Bucket Operation Circuit.)

3. When ride control solenoid valve (3) is deactivated, pressurized oil (A1) in the bottom side circuit of lift arm cylinder (4) flows through charge-cut spool (7) and is contained in ride control accumulator (2).

2. Pressurized oil (A1) sent to lift arm cylinder (4) also flows to ride control valve (1).

f NOTE: Accumulated pressure in ride control

accumulator (2) prevents unexpected movement of the lift arm when ride control solenoid valve (3) is energized.

f NOTE: Refer to Control System / Ride Control. 1

A1 B1

9 11 10

5 TNDB-02-04-014

Activation Signal from Main Controller (MC)

A1- Lift Arm Cylinder Bottom Side Circuit

B1- Lift Arm Cylinder Rod Side Circuit

123-

Ride Control Valve Ride Control Accumulator Ride Control Solenoid Valve

456-

789-

Lift Arm Cylinder Pilot Pump Hydraulic Oil Tank

T2-4-34

Charge-Cut Spool Ride Control Spool Relief Valve

10- Orifice 11- Check Valve

SECTION 2 SYSTEM Group 4 Hydraulic System  Stop accumulating ride control accumulator (2) 1. When oil pressure in ride control accumulator (2) increases above the specified pressure (reaches the charge-cut pressure), charge-cut spool (7) is moved.

2. Pressurized oil (A1) in ride control valve (1) is blocked by charge-cut spool (7) and pressurized oil stops accumulating in ride control accumulator (2).

A1 B1

9 11 10

5 TNDB-02-04-024

Activation Signal from Main Controller (MC)

A1- Lift Arm Cylinder Bottom Side Circuit

B1- Lift Arm Cylinder Rod Side Circuit

123-

Ride Control Valve Ride Control Accumulator Ride Control Solenoid Valve

456-

789-

Lift Arm Cylinder Pilot Pump Hydraulic Oil Tank

T2-4-35

Charge-Cut Spool Ride Control Spool Relief Valve

10- Orifice 11- Check Valve

SECTION 2 SYSTEM Group 4 Hydraulic System  Ride Control: When pushing downward on the lift arm 1. When the conditions for ride control exist, ride control activation signal from Main Controller (MC) (a) shifts ride control solenoid valve (3).

5. When the force pushing down the lift arm occurs, pressurized oil in the base end circuit of lift arm cylinder (4) (A1) is accumulated in ride control accumulator (2) through ride control spool (8).

2. Pressurized oil from pilot pump (5) flows through ride control solenoid valve (3) and shifts ride control spool (8).

6. Therefore, cycling pressures at bottom side circuit (A1) of lift arm cylinder (4) is regulated.

3. Pressurized oil in the base end circuit of lift arm cylinder (4) (A1) is connected to ride control accumulator (2) via ride control spool (8).

f NOTE: When the ride control is deactivated, the fore

and aft pitching of the machine occurs when driving on rough roads.

4. Pressurized oil in the rod side circuit of lift arm cylinder (4) (B1) is connected to hydraulic tank (6) via ride control spool (8).

9 A1

5 TNDB-02-04-025

Activation Signal from Main Controller (MC)

A1- Lift Arm Cylinder Bottom Side Circuit

B1- Lift Arm Cylinder Rod Side Circuit

123-

Ride Control Valve Ride Control Accumulator Ride Control Solenoid Valve

456-

789-

Lift Arm Cylinder Pilot Pump Hydraulic Oil Tank

T2-4-36

Charge-Cut Spool Ride Control Spool Relief Valve

10- Orifice 11- Check Valve

SECTION 2 SYSTEM Group 4 Hydraulic System  Ride Control: When pushing up on the lift arm 1. When fore and aft pitching of the loader results in pushing up on the lift arm base end circuit, pressure of lift arm cylinder (4) decreases. Pressurized oil from ride control accumulator (2) is supplied to base end circuit of lift arm cylinder (4) through ride control spool (8).

4. Relief valve (9) prevents the pressure in the circuit (between ride control valve and lift arm cylinder) from increasing over the set pressure while the ride control is activated. 5. Make-up valve (11) draws pressurized oil from hydraulic oil tank (6) and prevents cavitation from occurring when the pressure in the circuit (between ride control valve and lift arm cylinder) decreases below the specified value.

2. Therefore, pressure decrease at base end circuit of lift arm cylinder (4) (A1) is regulated. 3. Thus, fore and aft pitching of the machine is reduced by reducing pressure difference between base end circuit (A1) and rod side circuit (B1) of lift arm cylinder (4).

5 TNDB-02-04-042

Activation Signal from Main Controller (MC)

A1- Lift Arm Cylinder Bottom Side Circuit

B1- Lift Arm Cylinder Rod Side Circuit

123-

Ride Control Valve Ride Control Accumulator Ride Control Solenoid Valve

456-

789-

Lift Arm Cylinder Pilot Pump Hydraulic Oil Tank

T2-4-37

Charge-Cut Spool Ride Control Spool Relief Valve

10- Orifice 11- Check Valve

SECTION 2 SYSTEM Group 4 Hydraulic System Exhaust Filter Regeneration Control Circuit Purpose: A load is applied to the engine during manual or auto regeneration of the exhaust filter by increasing the load to hydraulic pump (6). Therefore, the exhaust temperature is raised up to the temperature that a catalyst is able to be activated. Operation: 1. Pressurized oil from pilot pump (9) is routed to exhaust filter regeneration control solenoid valve (4). (Refer to Charging Circuit.) 2. When the conditions for exhaust filter regeneration exist, exhaust filter regeneration control solenoid valve (4) is turned ON by signal (a) from Main Controller (MC) and the spool is moved to the left. (Refer to SYSTEM / Control System.) 3. Pilot pressurized oil (PibX) from exhaust filter regeneration control solenoid valve (4) moves exhaust filter regeneration / quick coupler spool (2) to the left. 4. When the control lever is in the neutral position, pressurized oil from main pump (6) flows to exhaust filter regeneration / quick coupler spool (2) and orifice (3) through neutral circuit (7) and check valve (8). 5. Pressurized oil from main pump (6) is reduced by orifice (3) and the pressure in neutral circuit (7) increases. 6. Consequently, the load applied to main pump (6) increases and regeneration of the exhaust filter becomes possible. (Refer to SYSTEM / Hydraulic System.)

T2-4-38

SECTION 2 SYSTEM Group 4 Hydraulic System

2 1

PibX

8 a

TNDF-02-04-007

Activation Signal from Main Controller (MC)

12-

Multiple Control Valve Exhaust Filter Regeneration/ Quick Coupler Spool

34-

Orifice Exhaust Filter Regeneration Control Solenoid Valve

567-

T2-4-39

Hydraulic Oil Tank Main Pump Neutral Circuit

8- Check Valve 9- Pilot Pump 10- Spool

SECTION 2 SYSTEM Group 4 Hydraulic System Quick Coupler Circuit (Option) IMPORTANT: Do not use port AX in multiple control valve (6) except the quick coupler circuit (option).  When locked: 1. Pressurized oil from pilot pump (10) is routed to quick coupler pilot solenoid valve (11). (Refer to Charging Circuit.) 2. When the quick coupler switch is set to the LOCK position, quick coupler pilot solenoid valve (11) is turned ON and pilot spool (12) is moved to the left. 3. Pilot pressurized oil (PiaX) from quick coupler pilot solenoid valve (11) moves exhaust filter regeneration/ quick coupler spool (7) in multiple control valve (6) to the right. 4. Therefore, pressurized oil from main pump (8) is routed to pilot port P in coupler cylinder selector solenoid valve (3) through exhaust filter regeneration/ quick coupler spool (7) and port AX. 5. On the other hand, coupler cylinder selector solenoid valve (3) is turned OFF and spool (2) is moved to the left by the spring force. 6. Pressurized oil from pilot port P pushes to open pilot check valve (5) through spool (2) and flows to the bottom side of coupler cylinder (4) through output port A. 7. Pressurized oil in the rod side of coupler cylinder (4) flows to tank port T through output port B in coupler cylinder selector solenoid valve (3) and spool (2). 8. Therefore, coupler cylinder (4) is locked (extended).

fNOTE: Check valve (13) is provided in order to prevent returning oil through multiple control valve (6) from flowing reversely. Therefore, coupler cylinder (4) is prevented from malfunctioning (release).

T2-4-40

SECTION 2 SYSTEM Group 4 Hydraulic System

6 5 B

7 PiaX

12 a

10 TNDF-02-04-008

Signal from Quick Coupler Switch

PT-

Pilot Port Tank Port

AB-

123-

Quick Coupler Circuit (OPT) Spool Coupler Cylinder Selector Solenoid Valve Coupler Cylinder

567-

Pilot Check Valve Multiple Control Valve Exhaust Filter Regeneration/ Quick Coupler Spool Main Pump

9- Hydraulic Oil Tank 10- Pilot Pump 11- Quick Coupler Pilot Solenoid Valve (OPT) 12- Pilot Spool

fNOTE: The illustration shows the oil flow during quick coupler lock operation.

T2-4-41

Output Port (Bottom Side) Output Port (Rod Side) 13- Check Valve

SECTION 2 SYSTEM Group 4 Hydraulic System  When released: 1. When the quick coupler switch is set to the UNLOCK position, quick coupler pilot solenoid valve (11) is kept ON and pilot spool (12) is in the left. 2. Pilot pressurized oil (PiaX) from quick coupler pilot solenoid valve (11) moves exhaust filter regeneration/ quick coupler spool (7) in multiple control valve (6) to the right. 3. Pressurized oil from main pump (8) is routed to pilot port P in coupler cylinder selector solenoid valve (3) through exhaust filter regeneration/ quick coupler spool (7) and port AX. 4. On the other hand, coupler cylinder selector solenoid valve (3) is turned ON and spool (2) is moved to the right. 5. Pressurized oil from pilot port P flows to the rod side of coupler cylinder (4) through spool (2) and output port B. 6. Pressurized oil in output port B routes pilot pressure to pilot check valve (5) and pushes to open it. 7. Therefore, pressurized oil in the bottom side of coupler cylinder (4) flows to tank port T through output port A in coupler cylinder selector solenoid valve (3) and spool (2). 8. Consequently, coupler cylinder (4) is released (shortened).

T2-4-42

SECTION 2 SYSTEM Group 4 Hydraulic System

6 5 B

2 a T

7 PiaX

12 a

10 TNDF-02-04-009

Signal from Quick Coupler Switch

PT-

Pilot Port Tank Port

AB-

123-

Quick Coupler Circuit (OPT) Spool Coupler Cylinder Selector Solenoid Valve Coupler Cylinder

567-

Pilot Check Valve Multiple Control Valve Exhaust Filter Regeneration/ Quick Coupler Spool Main Pump

9- Hydraulic Oil Tank 10- Pilot Pump 11- Quick Coupler Pilot Solenoid Valve (OPT) 12- Pilot Spool

fNOTE: The illustration shows the oil flow during quick coupler lock operation.

T2-4-43

Output Port (Bottom Side) Output Port (Rod Side) 13- Check Valve

SECTION 2 SYSTEM Group 4 Hydraulic System HST Circuit Outline 1. HST (Hydrostatic Transmission) circuit is a closed circuit including HST pump (1), HST motor 1 (5), and HST motor 2 (4). 2. HST pump (1) is directly activated by the driving force of the engine. In addition, HST motor 1 (5) and HST motor 2 (4) are rotated by pressurized oil from HST pump (1). 3. The output power of HST motor 1 (5) and HST motor 2 (4) are transmitted to transmission (6), front propeller shaft (11), rear propeller shaft (10), front axle (12), rear axle (9), and tires in sequence. 4. HST charging pump (2) is a built-in pump in HST pump (1) and is driven by the rotation of it. 5. HST charging pump (2) draws hydraulic oil from hydraulic oil tank (8) and delivers it. The delivered pressurized oil is supplied to the HST circuit through HST charge oil filter (3). 6. Pressurized oil from HST charging pump (2) is supplied as pilot pressurized oil for the pump displacement angle control of HST pump (1). In addition, it is used for lubrication and cooling of the HST circuit.

T2-4-44

SECTION 2 SYSTEM Group 4 Hydraulic System

1 7 2

8 4

6 5

123-

HST Pump HST Charging Pump HST Charge Oil Filter

456-

HST Motor 2 HST Motor 1 Transmission

789-

T2-4-45

Engine Hydraulic Oil Tank Rear Axle

T4FC-02-03-015

10- Third (Rear) Propeller Shaft 11- Second (Front) Propeller Shaft 12- Front Axle

SECTION 2 SYSTEM Group 4 Hydraulic System Charge Circuit

Neutral Circuit

1. Pressurized oil from Hydrostatic Transmission (HST) charging pump (7) flows to low-pressure relief valve (8) through HST charge oil filter (6).

1. When the forward/reverse lever is in the neutral position, forward/reverse control solenoid valve (3) is turned OFF by the OFF signal from the HST controller and is kept in the neutral position.

2. The pressure of pressurized oil from HST charging pump (7) is changed according to the delivery flow rate. Low-pressure relief valve (8) makes the pressure of pressurized oil from HST charging pump (7) the set pressure. 3. Pressurized oil from HST charging pump (7) flows to pump displacement angle control solenoid valve (4) through cutoff valve (5) as pilot pressurized oil for the displacement angle control cylinder (2) control. 4. Pump displacement angle control solenoid valve (4) adjusts the pressure of pilot pressurized oil according to signal (c) from the HST controller. It supplies pilot pressurized oil to displacement angle control cylinder (4) through forward/reverse control solenoid valve (3). Then, it controls the displacement angle of HST pump (1).

2. As pressurized oil from pump displacement angle control solenoid valve (4) is blocked by the spool of forward/reverse control solenoid valve (3), pressurized oil in displacement angle control cylinder (2) flows to drain (13) in the pump casing through forward/reverse control solenoid valve (3). 3. Therefore, displacement angle control cylinder (2) becomes neutral and the displacement angle of HST pump (1) is kept in the neutral position. 4. Consequently, as pressurized oil from HST pump (1) is not delivered, HST motor 1 (11) and HST motor 2 (10) are not activated.

5. One of pressurized oil from HST charging pump (7) is routed to high-pressure relief valve (9). 6. High-pressure relief valve (9) has the check valve (12) function. When the pressurized oil flow rate in the low-pressure side circuit is insufficient, check valve (12) is opened and pressurized oil from HST charging pump (7) is supplied to the low-pressure side in the HST circuit. 7. The relieved pressurized oil in low-pressure relief valve (8) flows to drain (13) in the pump casing and is used for lubrication and cooling of the HST circuit.

f NOTE: The pump delivery flow rate of HST charging

pump (7) is proportional to the engine speed. Therefore, the displacement angle control pressure of HST pump (1) is almost proportional to the engine speed.

T2-4-46

SECTION 2 SYSTEM Group 4 Hydraulic System 4

13 b

3 B

2 7

1 9

8 10

TNDF-02-04-010 A-

Port A (Forward Side)

B-

Port B (Reverse Side)

Signal from HST Controller

12-

HST Pump Displacement Angle Control Cylinder Forward/Reverse Control Solenoid Valve

Pump Displacement Angle Control Solenoid Valve Cutoff Valve HST Charge Oil Filter HST Charging Pump

89101112-

Low-Pressure Relief Valve High-Pressure Relief Valve HST Motor 2 HST Motor 1 Check Valve

567-

T2-4-47

13- Drain in Pump Case

SECTION 2 SYSTEM Group 4 Hydraulic System Forward Circuit

Reverse Circuit

1. When the forward/reverse lever is set to the forward position, the forward side solenoid valve of forward/ reverse control solenoid valve (3) is turned ON by signal (a) from the HST controller and the spool is moved to the right.

1. When the forward/reverse lever is set to the reverse position, the reverse side solenoid valve of forward/ reverse control solenoid valve (3) is turned ON by signal (b) from the HST controller and the spool is moved to the left.

2. Therefore, pilot pressurized oil from pump displacement angle control solenoid valve (4) is supplied to the right of displacement angle control cylinder (2) through the spool of forward/reverse control solenoid valve (3).

2. Therefore, pilot pressurized oil from pump displacement angle control solenoid valve (4) is supplied to the left of displacement angle control cylinder (2) and the displacement angle of HST pump (1) is changed contrary to the forward side.

3. The piston of displacement angle control cylinder (2) is moved to the left.

3. Therefore, pressurized oil from HST pump (1) is delivered from port A.

4. Therefore, as the displacement angle of HST pump (1) is changed to the forward position from the neutral position, pressurized oil from HST pump (1) is delivered from port B.

4. Consequently, HST motor 1 (11) and HST motor 2 (10) are rotated to the reverse direction.

5. Consequently, HST motor 1 (11) and HST motor 2 (10) are rotated to the forward direction.

T2-4-48

SECTION 2 SYSTEM Group 4 Hydraulic System 4

13 b

3 B

2 7

1 9

8 10

TNDF-02-04-011 A-

Port A (Forward Side)

B-

Port B (Reverse Side)

Signal from HST Controller

12-

HST Pump Displacement Angle Control Cylinder Forward/Reverse Control Solenoid Valve

Pump Displacement Angle Control Solenoid Valve Cutoff Valve HST Charge Oil Filter HST Charging Pump

89101112-

Low-Pressure Relief Valve High-Pressure Relief Valve HST Motor 2 HST Motor 1 Check Valve

567-

f NOTE: The illustration shows the forward circuit. T2-4-49

13- Drain in Pump Case

SECTION 2 SYSTEM Group 4 Hydraulic System Inching Circuit 1. When the brake pedal is depressed, the spool of pump displacement angle control solenoid valve (4) is shifted by signal (c) from the HST controller and is connected to drain (13) in the pump casing. 2. Therefore, the displacement angle control pressure of HST pump (1) decreases and displacement angle control cylinder (2) returns to the neutral position. 3. Consequently, the displacement angle of HST pump (1) is changed to the neutral position and the delivery flow rate of HST pump (1) decreases. 4. Therefore, the rotation speed of HST motor 1 (11) and HST motor 2 (10) are decreased. Then, the vehicle speed is decelerated. 5. The decrease rate of the displacement angle control pressure of HST pump (1) varies depending on the brake pedal operating amount. When the brake pedal is depressed fully, the displacement angle of HST pump (1) is in the neutral position.

T2-4-50

SECTION 2 SYSTEM Group 4 Hydraulic System 4

13 b

3 B

2 7

1 9

8 10

TNDF-02-04-013 A-

Port A (Forward Side)

B-

Port B (Reverse Side)

Signal from HST Controller

12-

HST Pump Displacement Angle Control Cylinder Forward/Reverse Control Solenoid Valve

Pump Displacement Angle Control Solenoid Valve Cutoff Valve HST Charge Oil Filter HST Charging Pump

89101112-

Low-Pressure Relief Valve High-Pressure Relief Valve HST Motor 2 HST Motor 1 Check Valve

567-

T2-4-51

13- Drain in Pump Case

SECTION 2 SYSTEM Group 4 Hydraulic System Transmission Circuit Outline 1. Transmission charge pump (4) draws transmission oil from oil pan (3) through the suction filter and delivers it. 2. The delivered pressurized oil flows to clutch pressure control solenoid valve (6) through transmission charge filter (5). 3. Pressurized oil flowing to clutch pressure control solenoid valve (6) flows to clutch (2) with clutch (2) connected as pilot pressurized oil for the clutch control, and returns to oil pan (3) with clutch (2) disconnected. 4. In addition, pressurized oil flowing to clutch pressure control solenoid valve (6) is used for lubrication of transmission (1), and returns to oil pan (3) through each part of transmission (1).

f NOTE: Clutch (2) is provided in the input shaft at the HST motor 1 (9) side in transmission (1).

T2-4-52

SECTION 2 SYSTEM Group 4 Hydraulic System

2 9

T4FC-02-03-019

123-

Transmission Clutch Oil Pan

45-

Transmission Charge Pump Transmission Charge Filter

67-

T2-4-53

Clutch Pressure Control Solenoid Valve Lubrication Circuit

89-

HST Motor 2 HST Motor 1

SECTION 2 SYSTEM Group 4 Hydraulic System Clutch Connecting Circuit 1. Pressurized oil from transmission charge pump (9) flows to clutch pressure control solenoid valve (6) through transmission charge filter (8). The relief valve is provided for clutch pressure control solenoid valve (6) and keeps the circuit pressure constant.

E2 E

2. The HST controller controls connection of clutch (12). The hydraulic waveform of clutch connection is set by the HST controller. The control current value for proportional solenoid valve (4) in clutch pressure control solenoid valve (6) is calculated based on it.

3. When connect clutch (12) the HST controller supplies the calculated control current to proportional solenoid valve (4).

E1 h

4. Proportional solenoid valve (4) moves the spool to the right according to the supplied control current and supplies pressurized oil to selector valve (3).

T4FC-02-03-021

5. Therefore, the spool of selector valve (3) is moved to the left and pressurized oil is routed to clutch (12) so that clutch pressure increases.

E- Control Current E1- Minumum Current Value E2- Maximum Current Value

6. Consequently, clutch (12) is connected according to the set hydraulic waveform. 7. While clutch (12) is connected, current continues to be supplied to proportional solenoid valve (4) from the HST controller.

T2-4-54

Ep- Hydraulic Waveform on Control Current of Solenoid Valve h- Time

SECTION 2 SYSTEM Group 4 Hydraulic System

3 12

5 6 7

TNDF-02-04-016

1234-

Transmission Lubrication Circuit Selector Valve Proportional Solenoid Valve

567-

Relief Valve Clutch Pressure Control Solenoid Valve Oil Pan

891011-

Transmission Charge Filter Transmission Charge Pump HST Motor 1 HST Motor 2

f NOTE: The illustration shows the oil flow When clutch (12) is connected.

T2-4-55

12- Clutch

SECTION 2 SYSTEM Group 4 Hydraulic System Clutch Disconnecting Circuit

Transmission Lubrication Circuit

1. While clutch (12) is connected, the HST controller supplies current and proportional solenoid valve (4) in clutch pressure control solenoid valve (6) is activated. Therefore, the spool is in the right.

1. The relief valve (5) function in clutch pressure control solenoid valve (6) allows the unused transmission oil for connecting/disconnecting clutch (12) to flow to each part of transmission (1) for lubrication.

2. Pressurized oil is routed to selector valve (3) and the spool is in the left. 3. When disconnect clutch (12) the HST controller stops supplying current to proportional solenoid valve (4). Therefore, the spool in proportional solenoid valve (4) is moved to the left and the oil passage is connected to oil pan (7). 4. Therefore, the spool in selector valve (3) is moved to the right and pressurized oil from transmission charge pump (9) is not supplied to clutch (12). 5. Consequently, clutch pressure decreases and clutch (12) is disconnected.

T2-4-56

2. The used transmission oil for lubrication flows to each part of transmission (1) and returns to oil pan (7).

SECTION 2 SYSTEM Group 4 Hydraulic System

3 12

5 6 7

1234-

Transmission Lubrication Circuit Selector Valve Proportional Solenoid Valve

567-

Relief Valve Clutch Pressure Control Solenoid Valve Oil Pan

891011-

Transmission Charge Filter Transmission Charge Pump HST Motor 1 HST Motor 2

f NOTE: The illustration shows the oil flow when clutch (12) is disconnected.

T2-4-57

12- Clutch

TNDF-02-04-015

SECTION 2 SYSTEM Group 4 Hydraulic System Fan Circuit Outline 1. Pressurized oil from pilot pump (1) is supplied to fan valve (3) through brake charge valve (2) and rotates fan motor (4). 2. Fan valve (3) controls the flow rate flowing to fan motor (4) according to the signals from Main Controller (MC) and adjusts the fan motor (4) speed. 3. In case of fan reverse rotation control circuit, the flow direction flowing to fan motor (4) is controlled by fan reverse rotation control solenoid valve (6). 4. Therefore, the rotation of fan motor (4) is shifted from normal rotation to reverse rotation

f NOTE: Pilot pump (1) is a 4-gear pump unit. Pressurized

oil from pilot pump (1) is supplied to the pilot circuit, the charging circuit, and the fan circuit through brake charge valve (2). (Refer to Pilot Circuit / Charging Circuit.)

T2-4-58

SECTION 2 SYSTEM Group 4 Hydraulic System

2 A

TNDF-02-04-020 A-

With Fan Reverse Rotation Control Solenoid Valve

12-

Pilot Pump Brake Charge Valve

34-

Fan Valve Fan Motor

T2-4-59

Hydraulic Oil Tank

Fan Reverse Rotation Control Solenoid Valve

SECTION 2 SYSTEM Group 4 Hydraulic System Fan Normal Rotation Control Circuit 1. Pressurized oil from pilot pump (8) supplied to fan valve (1) is supplied to port P2 in fan motor (2), and rotates fan motor (2). 2. Pressurized oil from pilot pump (8) is also routed to fan speed control solenoid valve (6) and fan control valve (7). 3. Main Controller (MC) controls fan speed control solenoid valve (6) according to the actual engine speed and hydraulic oil temperature. (Refer to SYSTEM / Control System.) 4. When fan speed control solenoid valve (6) is activated by signal (a) from MC, fan control valve (7) is activated and pressurized oil from pilot pump (8) returns to hydraulic oil tank (9). (Relief operation) 5. Therefore, the flow rate flowing to fan motor (2) decreases and the fan motor (2) speed decreases. 6. Consequently, the fan motor (2) speed is controlled by adjusting the amount of pressurized oil flowing back to hydraulic oil tank (9) from fan valve (1). 7. Anti-void valve (3) refills hydraulic oil from hydraulic oil tank (9) and prevents cavitation from occurring when the pressure in the fan circuit decreases (the fan motor speed change, engine shutdown, etc.). 8. Returning oil from fan motor (2) returns to hydraulic oil tank (9) through the oil cooler.

T2-4-60

SECTION 2 SYSTEM Group 4 Hydraulic System  Normal rotation

3 B

9 P

TNDF-02-04-035

 Normal rotation when relieving

3 1

9 P

P1- Port P1 (Reverse Rotation) P2- Port P2 (Normal Rotation)

aP-

Signal from MC Pump Port

T- Tank Port Dr- Drain Port

123-

Fan Speed Control Solenoid Valve Fan Control Valve

89-

Fan Valve Fan Motor Anti-Void Valve

T2-4-61

Pilot Pump Hydraulic Oil Tank

TNDF-02-04-036

SECTION 2 SYSTEM Group 4 Hydraulic System Fan Normal Rotation Control Circuit

Fan Reverse Rotation Control Circuit

f NOTE: The operation of fan valve (1) (with fan reverse

1. Pressurized oil from pilot pump (8) is also routed to fan reverse rotation control solenoid valve (5).

rotation circuit) is explained. 1. Pressurized oil from pilot pump (8) is supplied to fan valve (1), is supplied to port P2 in fan motor (2) through fan reverse rotation spool (4), and rotates fan motor (2).

2. When the fan reversing switch is set to the ON position, fan reverse rotation control solenoid valve (5) is activated by signal (b) from MC.

2. Pressurized oil from pilot pump (8) is also routed to fan speed control solenoid valve (6) and fan control valve (7). 3. MC controls fan speed control solenoid valve (6) according to the actual engine speed and hydraulic oil temperature. (Refer to SYSTEM / Control System.) 4. When fan speed control solenoid valve (6) is activated by signal (b) from MC, fan control valve (7) is activated and pressurized oil from pilot pump (8) returns to hydraulic oil tank (9). 5. Therefore, the flow rate flowing to fan motor (2) decreases and the fan motor (2) speed decreases. 6. Consequently, the fan motor (2) speed is controlled by adjusting the amount of pressurized oil flowing back to hydraulic oil tank (9) from fan valve (1). 7. Anti-void valve (3) refills hydraulic oil from hydraulic oil tank (9) and prevents cavitation from occurring when the pressure in the fan circuit decreases (the fan motor speed change, engine shutdown, etc.). 8. Returning oil from fan valve (1) returns to hydraulic oil tank (9) through the oil cooler.

T2-4-62

3. Therefore, fan reverse rotation spool (4) is shifted by pressurized oil flowing through fan reverse rotation control solenoid valve (5). 4. Consequently, the flow direction flowing to fan motor (2) is shifted and fan motor (2) rotates in reverse.

SECTION 2 SYSTEM Group 4 Hydraulic System  Normal rotation

 Reverse rotation

4 5

b a

9 7

9 8

TNED-02-04-035

TNED-02-04-052

 Normal rotation when relieving

4 5

9 7

6 9 8

TNED-02-04-036

P1- Port P1 (Reverse Rotation) P2- Port P2 (Normal Rotation)

Signal from MC

Signal from MC (Fan Reversing Switch)

123-

45-

Fan Reverse Rotation Spool Fan Reverse Rotation Control Solenoid Valve

Fan Speed Control Solenoid Valve Fan Control Valve

Fan Valve Fan Motor Anti-Void Valve

f NOTE: The illustration shows the oil flow for fan valve (1) (with fan reverse rotation circuit). T2-4-63

89-

Pilot Pump Hydraulic Oil Tank

SECTION 2 SYSTEM Group 4 Hydraulic System (Blank)

T2-4-64

SECTION 2 SYSTEM Group 5 Electrical System Outline The electrical circuit is broadly divided into the main circuit, steering column monitor circuit, accessory circuit, and control circuit.  Main Circuit: Operates the engine and the accessory related circuits.  Steering Column Monitor Circuit: Is operated when the machine operation. Consists of head lights, turn signal lights, brake lights, and horn.  Accessory Circuit: Operates the accessory circuit. Consists of column display controller, relays, and switches.  Control Circuit: Controls the engine, Hydrostatic Transmission (HST) pump, HST motor, transmission, and valve. Consists of the actuators such as solenoid valves, Main Controller (MC), Engine Control Module (ECM), HST controller, sensors, and switches. (Refer to SYSTEM / Control System.)

T2-5-1

SECTION 2 SYSTEM Group 5 Electrical System Main Circuit The major functions and circuits in the main circuit are as follows.  Electric Power Circuit: Supplies all electric power to all electrical systems on the machine. {Key switch, Battery, Fuses (Fuse box, Fusible link)}  Light Bulb Check Circuit: Is the circuit to check the bulbs of monitor indicators.  CAN Circuit: Performs communication between each controller.  Accessory Circuit: Is operated when the key switch is in the ACC position.  Starting Circuit: Starts the engine. (Key switch, Starter, Starter relay 1)  Charging Circuit: Supplies electric power to the batteries and charges them. {Alternator, (Regulator)}  Surge Voltage Prevention Circuit: Prevents the occurrence of serge voltage developed when stopping the engine. (Load dump relay)  Engine Stop Circuit (Key switch: OFF): Stops the engine by using Engine Control Module (ECM). (MC, ECM)  Auto Idling Stop Circuit: Stops the engine automatically when the fixed conditions exist. (Main Controller (MC), Auto idling stop relay, ACC cut relay, Key switch ON cut relay) NOTE: Auto idling stop function is not used.

T2-5-2

SECTION 2 SYSTEM Group 5 Electrical System (Blank)

T2-5-3

SECTION 2 SYSTEM Group 5 Electrical System Electric Power Circuit (Key Switch: OFF) The battery (1) minus terminal is grounded to the body. Current from the battery (1) plus terminal flows as shown below when key switch (4) is in the OFF position. Battery (1)

Fusible Link A (3)

Key Switch (4) Terminal B Fuse Box B (5)

Terminal #2

Light Switch (19)

Terminal #3

Cab Light (20) Radio (Backup Power) (21)

Terminal #4

Auxiliary (Power) (22)

Terminal #5

Horn Relay (Power) (17) Horn Switch (Power) (18)

Terminal #6

Flasher Relay (15) Hazard Light Switch (16)

Terminal #7

Load Dump Relay (6) MC (Power) (7) Information Controller (Backup Power) (8) Column Display Controller (Backup Power) (9) Communication Terminal (Power) (10)

Terminal #8

ECM Main Relay (12) Fuel Pump Relay (13)

T2-5-4

SECTION 2 SYSTEM Group 5 Electrical System 1

5 6

9 10

12 13

15 16

(7) (8) (6) (5) (2) (3) (4) 22 21 20 19 18 17

1234567-

Battery Battery Relay Fusible Link A (65A) Key Switch Fuse Box B Load Dump Relay Main Controller (MC) (Power)

Information Controller (Backup Power) 9- Column Display Controller (Backup power) 10- Communication Terminal (Power)

12- Engine Control Module (ECM) Main Relay 13- Fuel Pump Relay (Power) 15- Flasher Relay 16- Hazard Light Switch 17- Horn Relay 18- Horn Switch (Power)

f NOTE: The number in parentheses indicates the fuse No.

T2-5-5

TNDF-02-05-001

19202122-

Light Switch Cab Light Radio (Backup Power) Auxiliary (Power)

SECTION 2 SYSTEM Group 5 Electrical System Light Bulb Check Circuit (Key Switch: ON) 1. When key switch (4) is set to ON position (7), terminal B is connected to terminals ACC (5) and M (6) in key switch (4). 2. When current (a) from terminal M (6) in key switch (4) flows to terminal #1-2 in the column display controller through fuse #13 of fuse box B (8). 3. When the column display controller lights the indicators for two seconds, checks the bulbs, and starts the monitor display. (Refer to the separated volume, Operator’s Manual for details of Light Bulb Check.)

T2-5-6

SECTION 2 SYSTEM Group 5 Electrical System

3 1

(13)

4 5 6

TNDF-02-05-021 a-

To Column Display Controller (Terminal #1-2)

123-

Battery Battery Relay Fusible Link A (65 A)

456-

Key Switch Terminal ACC Terminal M

78-

f NOTE: The number in parentheses shows the fuse No.

T2-5-7

ON Position Fuse Box B

SECTION 2 SYSTEM Group 5 Electrical System CAN Circuit CAN (Controller Area Network) is based on International Organization for Standardization (ISO) Standards of the serial communication protocol. Three networks CAN 1 (1), CAN 2 (5) and CAN 3 (18) (CAN bus (4)) are equipped for this machine. CAN 1 (1) is used for the engine control. CAN 2 (5) is used for the accessories. CAN 3 (18) is used for the turbocharger control. CAN bus (4) consists of two harnesses, CAN-H (High) (2) and CAN-L (Low) (3). Each controller judges the CAN bus (4) level due to potential difference between CAN-H (High) (2) and CAN-L (Low) (3). Each controller arranges the CAN bus (4) level and sends the signal and data to other controllers. Termination resistors (120 Ω) (17) are installed to both ends of CAN harness.

T2-5-8

SECTION 2 SYSTEM Group 5 Electrical System 2 1 3

2 5 3

TDAA-02-05-001

18 9

10 11

12 5

17 17 19 13

TNDB-02-01-0011

12345-

CAN 1 CAN-H (High) CAN-L (Low) CAN Bus CAN 2

6789-

VGS (Variable Geometry System) Controller ECM (Engine Control Module) MC (Main Controller) HST (Hydrostatic Transmission) Controller

101112131417-

T2-5-9

Communication Controller Information Controller MPDr. (Maintenance Pro Dr.) Air Conditioner Controller Column Display Controller Termination Resistor (120 Ω)

18- CAN 3 19- Rear View Camera Monitor (Option)

SECTION 2 SYSTEM Group 5 Electrical System Accessory Circuit (Key Switch: ACC) 1. When key switch (4) is set to ACC position (5), terminal B is connected to terminal ACC (6) in key switch (4). 2. Current from terminal ACC (6) in key switch (4) flows to terminal #3 in radio (7) through fuse #1 in fuse box B (8). 3. Therefore, current makes radio (7) operable.

T2-5-10

SECTION 2 SYSTEM Group 5 Electrical System 1

(1) 7 (3)

TNDF-02-05-002

123-

Battery Battery Relay Fusible Link A (65A)

456-

Key Switch ACC Position Terminal ACC

78-

f NOTE: The number in parentheses shows the fuse No.

T2-5-11

Radio Fuse Box B

SECTION 2 SYSTEM Group 5 Electrical System Starting Circuit (Key Switch: START)  Forward/Reverse Lever at Neutral Position 1. When key switch (4) is set to START position (5), terminal B is connected to terminal M (6) and terminal ST (7) in key switch (4).

9. Current from fuse #10 of fuse box B (8) flows to ECM (12) through ECM main relay (14) and the ECM (12) main power is turned ON.

2. Current from terminal M (6) flows through fuse #13 of fuse box B (8) and turns ON battery relay (2). Current from battery (1) is routed to terminal B of starter (18) and terminal C of starter relay 1 (17) through battery relay (2).

10. ECM (12) makes the engine starting condition. 11. In addition, current from terminal M (6) in key switch (4) flows to each controller as the signal indicating that key switch (4) is in START position (5).

3. When forward/reverse lever (10) is in neutral (N) position (24), neutral relay (15) is turned OFF. (Refer to Neutral Engine Start Circuit.) 4. Current from terminal ST (7) in key switch (4) flows to the coil through neutral relay (15), starter cut relay (16), and terminal S in starter relay 1 (17), and connects to the ground. 5. Therefore, starter relay 1 (17) is turned ON. Current which flows to terminal C of starter relay 1 (17) is routed to terminal S of starter (18) through terminal B. 6. Consequently, the relay in starter (18) is turned ON so that the starter motor rotates. 7. In addition, one of current which flows through terminal ST (7) and neutral relay (15) flows to terminal #100 in ECM (12). 8. When ECM (12) receives this signal, ECM (12) turns ON ECM main relay (14).

T2-5-12

SECTION 2 SYSTEM Group 5 Electrical System

3 9

19 (1-2) 20 (B-17)

22 (E-10) (14)

(13)

23 24 25

8 4

37 10 48

10 15

B S B

13 41 42 100 152

13 8 b

67 136 114

(10) 17

14 TNDF-02-05-003

1234567-

Battery Battery Relay Fusible Link A (65A) Key Switch START Position Terminal M Terminal ST

891011121314-

Fuse Box B Fusible Link (100 A) Forward/Reverse Lever HST Controller ECM Fuel Pump Relay ECM Main Relay

15161718192022-

f NOTE: The number in parentheses shows the fuse No.

T2-5-13

Neutral Relay Starter Cut Relay Starter Relay 1 Starter Column Display Controller Information Controller MC

23- Forward (F) Position 24- Neutral (N) Position 25- Reverse (R) Position

SECTION 2 SYSTEM Group 5 Electrical System Starter Relay 1 Operation 1. When key switch (4) is set to the START position, current is routed to terminal B-ST of key switch (4) and flows to the base of transistor Q2 through resistance R4 of starter relay 1 (17). Transistor Q2 is turned ON and current flows to coil L in starter relay 1 (17). 2. Consequently, as terminal #B is connected to terminal #S in starter (18), starter (18) is activated. 3. The alternator starts generating electricity after engine has started. Voltage at terminal R in starter relay 1 (17) increases. 4. When this voltage reaches 21 to 22 V, Zener diode Z is turned ON. Consequently, as transistor Q1 is turned ON and current does not flow to the base of transistor Q2, transistor Q2 is turned OFF. 5. At this time, as terminal #B is disconnected from terminal #S in starter (18), starter (18) is turned OFF.

fNOTE: In addition, C in the illustration is a condenser 1

to stabilize operating voltage. D4 is a diode to protect the circuit in case the battery (1) terminals are reversely connected.

T2-5-14

SECTION 2 SYSTEM Group 5 Electrical System

17 S

(1) R3

D3 R4

L C

(2)

D2 Q1

(1) M

S B

(2) C1

15 a-

From Alternator Terminal L

14-

Battery Key Switch

15- Neutral Relay 17- Starter Relay 1

1 ST

18- Starter

T2-5-15

T4GD-02-04-017

SECTION 2 SYSTEM Group 5 Electrical System Neutral Engine Start Circuit Purpose: The engine does not start with forward/reverse lever (10) set in forward (F) position (23) or reverse (R) position (25). Therefore, the engine is protected from unexpectedly starting out. 1. When key switch is set to START position (5), current (c) from battery (1) flows to forward/reverse lever (10) through battery relay (2) and fusible link (100 A) (9). 2. When forward/reverse lever (10) is set in forward (F) position (23) or reverse (R) position (25), current (a) from forward/reverse lever (10) flows to the coil in neutral relay (15), and flows to the ground. 3. Therefore, neutral relay (15) is turned ON. 4. When neutral relay (15) is turned ON, current from terminal ST (7) in key switch (4) stops flowing to starter cut relay (16). 5. Consequently, starter relay 1 (17) is turned OFF. As current which flows to terminal C in starter relay 1 (17) does not flow to terminal S in starter (18), the starter motor does not rotate.

T2-5-16

SECTION 2 SYSTEM Group 5 Electrical System

3 9

19 (1-2) 20 (B-17)

22 (E-10) (14)

(13)

23 24 25

8 4

37 10 48

10 15

B S B

13 41 42 100 152

13 8 b

67 136 114

(10) 17

14 TNDF-02-05-004

1234567-

Battery Battery Relay Fusible Link A (65A) Key Switch START Position Terminal M Terminal ST

891011121314-

Fuse Box B Fusible Link (100 A) Forward/Reverse Lever HST Controller ECM Fuel Pump Relay ECM Main Relay

15161718192022-

f NOTE: The number in parentheses shows the fuse No. f NOTE: The illustration shows the current flow when

forward/reverse lever (10) is in the forward (F) position.

T2-5-17

Neutral Relay Starter Cut Relay Starter Relay 1 Starter Column Display Controller Information Controller MC

23- Forward (F) Position 24- Neutral (N) Position 25- Reverse (R) Position

SECTION 2 SYSTEM Group 5 Electrical System Charging Circuit (Key Switch: ON) 1. After the engine starts and key switch (4) is released, key switch (4) is returned to the ON position. 2. Terminal B is connected to terminal ACC (7) and terminal M (8) in key switch (4) with key switch (4) set in the ON position. 3. Current from terminal M (8) turns ON battery relay (2) through terminal #13 in fuse box B (10). 4. Alternator (5) starts generating electricity with the engine running. Current from alternator (5) terminal B flows to battery (1) through fuse (100 A) (9) and battery relay (2), and charges battery (1). 5. In addition, current from alternator (5) terminal L flows to column display controller (a). 6. Column display controller (a) detects the alternator (5) generating electricity and turns off the alternator alarm on monitor.

T2-5-18

SECTION 2 SYSTEM Group 5 Electrical System

10 D8

3 9

12 A15

(13)

4 7 8

B L b a

5 TNDF-02-05-005

To Column Display Controller (Terminal 2-28)

bd-

To Information Controller To Battery Relay

123-

Battery Battery Relay Fusible Link A (65A)

457-

Key Switch Alternator Terminal ACC

8- Terminal M 9- Fusible Link (100 A) 10- Fuse Box B

f NOTE: The number in parentheses shows the fuse No.

T2-5-19

12- Information Controller 13- Load Dump Relay

SECTION 2 SYSTEM Group 5 Electrical System Alternator (5) Operation  Alternator (5) consists of field coil FC, stator coil SC, and diodes D.  Regulator (6) consists of transistors T1 and T2, Zener diode ZD, and resistances R1 and R2.  Terminal M (4) in the key switch is connected to base B of transistor T1 through R, RF, (R), and R1.  When battery relay (2) is in the ON position, the battery (1) voltage is applied to base B of transistor T1 in regulator (6) so that collector C is connected to emitter E. Therefore, field coil FC is grounded through transistor T1.

 At the beginning, no current is flowing through field coil FC. When the rotor starts rotating, alternate current is generated in stator coil SC due to the rotor remain magnetism.  When current flows through field coil FC, the rotor is further magnetized so that the generating voltage increases. Thereby, current through field coil FC increases. Therefore, generating voltage increases further and battery (1) start charging.

2 (R)

TDAA-02-05-004

12-

Battery Battery Relay

34-

To Key Switch Terminal B From Key Switch Terminal M

56-

T2-5-20

Alternator Regulator

SECTION 2 SYSTEM Group 5 Electrical System Regulator (6) Operation  When generating voltage increases more than the set voltage of Zener diode ZD, current flows to base B of transistor T2 and collector C is connected to emitter E.  Current flowing to base B of transistor T1 disappears due to transistor T2 operation so that transistor T1 is turned OFF.  No current flows through filed coil FC and generating voltage at stator coil SC decreases.

 When generating voltage decreases lower than the set voltage of Zener diode ZD, transistor T2 is turned OFF and transistor T1 is turned ON again.  Current flows through field coil FC and generating voltage at stator coil SC increases. The above operation is repeated so that the alternator (5) generating voltage is kept constant.

TDAA-02-05-003

12-

Battery Battery Relay

34-

To Key Switch Terminal B From Key Switch Terminal M

56-

T2-5-21

Alternator Regulator

SECTION 2 SYSTEM Group 5 Electrical System Surge Voltage Prevention Circuit 1. When the engine is stopped (key switch (4): OFF), current from terminal M (8) in key switch (4) disappears and battery relay (2) is turned OFF. 2. The engine continues to rotate due to inertia force just after key switch (4) is turned OFF so that alternator (5) continues to generate electricity. 3. As the generating current cannot flow to battery (1), surge voltage arises in the circuit and failures of the electronic components, such as the controller, possibly cause. For this reason, the surge voltage prevention circuit is provided. 4. When alternator (5) is generating electricity, current (b) from alternator (5) terminal L flows to terminal A15 of information controller (12). Information controller (12) connects terminal D8 to the ground. 5. Therefore, current flows to the coil side in load dump relay (13) and load dump relay (13) is turned ON. 6. When load dump relay (4) is turned ON, current (d) of battery (1) from load dump relay (3) flows to the coil side of battery relay (2) and battery relay (2) is turned ON. 7. Consequently, even if key switch (4) is turned OFF with the engine running, the generating current from alternator (5) terminal B flows to battery (1) through fusible link (100 A) (9) and battery relay (2). Then, the occurrence of serge voltage is prevented. 8. In addition, when a fixed time has passed since alternator (5) stops generating electricity, information controller (12) disconnect terminal D8 from the ground. Therefore, battery relay (2) is turned OFF.

T2-5-22

SECTION 2 SYSTEM Group 5 Electrical System

10 D8

(8)

3 9

12 A15

(13)

4 7 8

B L b a

5 TNDF-02-05-006

ab-

To Column Display Controller To Information Controller

To Battery Relay

123-

Battery Battery Relay Fusible Link A (65A)

457-

Key Switch Alternator Terminal ACC

8- Terminal M 9- Fusible Link (100 A) 10- Fuse Box B

f NOTE: The number in parentheses shows the fuse No.

T2-5-23

12- Information Controller 13- Load Dump Relay

SECTION 2 SYSTEM Group 5 Electrical System Engine Stop Circuit 1. When key switch (4) is set to OFF position (6) from ON position (7), current (a) indicating that key switch (4) is in ON position (7) stops flowing to terminal #134 of Engine Control Module (ECM) (9) from terminal M (5) in key switch (4). 2. ECM (9) stops fuel injection of the injector and stops the engine. 3. When the engine stops, ECM (9) turns OFF ECM main relay (11).

T2-5-24

SECTION 2 SYSTEM Group 5 Electrical System

3 2

(13)

134 100 9

10 8 b

(10)

123-

Battery Battery Relay Fusible Link A

456-

TNDF-02-05-009

Key Switch Terminal M OFF Position

789-

f NOTE: The number in parentheses shows the fuse No.

T2-5-25

ON Position Fuse Box B ECM

10- Fuel Pump Relay 11- ECM Main Relay 12- Glow Plug Relay

SECTION 2 SYSTEM Group 5 Electrical System Auto Idling Stop Circuit (Not Used) 1. When key switch (4) is in ON position (15), current from terminal M (5) excites battery relay (2) through key switch ON cut relay (8) and fuse #13 in fuse box B (6).

fNOTE: When restarting the engine, return key switch

2. In addition, current from terminal M (5) flows to the coils of auto idling stop relay (10), ACC cut relay (9), and key switch ON cut relay (8) through fuse #15 in fuse box B (6). 3. When all following conditions exist, Main Controller (MC) (11) connects terminal #B17 to the ground in it. (Refer to SYSTEM / Control System.) 4. Therefore, auto idling stop relay (10) is turned ON. ACC cut relay (9) and key switch ON cut relay (8) are also turned ON at the same time. 5. When key switch ON cut relay (8) is turned ON, current indicating that key switch (4) is in ON position (15) stops flowing to terminal #134 of Engine Control Module (ECM) (12) through fuse #14 in fuse box B (6). 6. At the same time, current which flows to fuse #13 in fuse box B (6) also stops flowing and battery relay (2) is turned OFF. 7. Therefore, this is the same case when key switch (4) is set to OFF position (16). ECM (12) stops fuel injection of the injector and stops the engine. 8. When the engine stops, ECM (12) turns OFF ECM main relay (13). Conditions:  Auto Idling Stop Setting: ON  Accelerator Pedal: Not applied  Parking Brake: Applied  Brake Pedal: Not applied  Forward/Reverse Lever: Neutral position  Front Attachment, Steering: Not operated  Coolant Temperature: 100 ºC (212 ºF) or less  HST Oil Temperature: 100 ºC (212 ºF) or less  Engine Speed: 850 min-1 or less  Except for exhaust filter manual regeneration  Abnormal Communication: None  Matching Control: Activated  Auto-Warming Up Control: Release

T2-5-26

(4) to OFF position (16) or ACC position. Then turn key switch (4) to START position, and engine starts.

SECTION 2 SYSTEM Group 5 Electrical System

3 2

1 8

9 6

6 (14)

(15)

(13) 15

B10 C10 C15

134 100 12

14 6 b

10 13

TNDF-02-05-008

12345-

Battery Battery Relay Fusible Link A (65 A) Key Switch Terminal M

689-

Fuse Box B Key Switch ON Cut Relay (Option) ACC Cut Relay (Option)

10- Auto Idling Stop Relay (Not used) 11- MC 12- ECM 13- ECM Main Relay

T2-5-27

14151617-

Fuel Pump Relay ON Position OFF Position Auto Idling Stop Switch (Not used)

SECTION 2 SYSTEM Group 5 Electrical System (Blank)

T2-5-28

SECTION 2 SYSTEM Group 5 Electrical System Steering Column Monitor Circuit  Head Light Circuit: for turning on and off head lights, clearance lights, license lights, and tail lights.  Hazard Light Circuit: for turning on and off hazard lights.  Turn Signal Light Circuit: for turning on and off turn signal lights.  Horn Circuit: for sounding horn.  Reverse Buzzer Circuit: for turning on and off reverse buzzer.  Brake Light Circuit: for turning on and off brake lights.  Parking Brake Circuit: for applying and releasing parking brake.

T2-5-29

SECTION 2 SYSTEM Group 5 Electrical System Head Light Circuit Clearance Light, License Light, Tail Light Circuit (Light Switch: Clearance Light Position (20)) 1. Current (a) from the battery flows to light switch (2) through fuse #2 in fuse box B (1). 2. When light switch (2) is set to clearance light position (20), current from fuse #2 in fuse box B (1) flows to fuses #11 and #12 in fuse box B (1) through light switch (2). 3. Current from fuses #11 and #12 flows to clearance lights (6, 9), tail lights (4, 7), and license light (8), and connects to the ground. 4. Therefore, clearance lights (6, 9), tail lights (4, 7), and license light (5) are turned on. 5. In addition, current from fuse #2 in fuse box B (1) flows to terminal #1-25 in column display controller (10) through light switch (2). 6. The input signal of terminal #1-25 is judged in column display controller (10). 7. Therefore, column display controller (10) turns on clearance light indicator (18).

fNOTE: License light (5) is optional.

T2-5-30

SECTION 2 SYSTEM Group 5 Electrical System 20 1

2 S OFF H

(2)

3 1-25

2-13

6 (11)

(12)

11 b

(5) 13

(1) 17

(19)

TNDF-02-05-011

From Battery

From Battery Relay

123456-

Fuse Box B Light Switch Dimmer Switch Tail Light (Left) License Light (OPT) Clearance Light (Right)

7910111213-

Tail Light (Right) Clearance Light (Left) Column Display Controller Fuse Box A Head Light Relay (Left) Head Light Relay (Right)

141516171819-

f NOTE: The number in parentheses shows the fuse No. T2-5-31

Head Light (Left) Head Light (Right) High Beam High Beam Relay Clearance Light Indicator High Beam Indicator

20212223-

Clearance Light Position Head Light Position Low Beam Position High Beam Position

SECTION 2 SYSTEM Group 5 Electrical System Head Light Circuit

fNOTE: The operation with dimmer switch (3) set in low

fNOTE: When light switch (2) is in head light position

beam position (22) is explained here.

1. When light switch (2) is set to head light position (21), current from fuse #2 in fuse box B (1) flows to dimmer switch (3) through light switch (2). 2. When dimmer switch (3) is set to low beam position (22), current from fuse #2 in fuse box B (1) flows to the coils in head light relays (right and left) (12, 13) through dimmer switch (3), and connects to the ground. 3. Therefore, head light relays (right and left) (12, 13) are turned ON. 4. When head light relays (right and left) (12, 13) are turned ON, current from fuses #5 and #1 in fuse box A (11) flows to head lights (right and left) (14, 15) through head light relays (right and left) (12, 13), and connects to the ground. 5. Therefore, head lights (right and left) (14, 15) are turned on.

T2-5-32

(21), head lights (14, 15), clearance lights (6, 9), tail lights (4, 7), and license lights (8) are turned on.

SECTION 2 SYSTEM Group 5 Electrical System 20 1

2 S OFF H

(2)

3 1-25

2-13

6 (11)

(12)

11 b

(5) 13

(1) 17

(19)

TNDF-02-05-012

From Battery

From Battery Relay

123456-

Fuse Box B Light Switch Dimmer Switch Tail Light (Left) License Light (OPT) Clearance Light (Right)

7910111213-

Tail Light (Right) Clearance Light (Left) Column Display Controller Fuse Box A Head Light Relay (Left) Head Light Relay (Right)

141516171819-

f NOTE: The number in parentheses shows the fuse No. T2-5-33

Head Light (Left) Head Light (Right) High Beam High Beam Relay Clearance Light Indicator High Beam Indicator

20212223-

Clearance Light Position Head Light Position Low Beam Position High Beam Position

SECTION 2 SYSTEM Group 5 Electrical System High Beam Circuit

fNOTE: When the turn signal lever is lowered with head

fNOTE: The operation with light switch (2) set in head

lights (14, 15) turned on, dimmer switch (3) is set to high beam position (23) and high beam (16) is turned on.

light position (21) is explained here.

1. When dimmer switch (3) is set to high beam position (23), current from fuse #2 in fuse box B (1) flows to the coil in high beam relay (17), and connects to the ground. 2. Therefore, high beam relay (17) is turned ON. 3. When high beam relay (17) is turned ON, current from fuse #19 in fuse box B (1) flows to high beams (16) in head lights (right and left) (14, 15) through high beam relay (17), and connects to the ground. 4. Therefore, high beams (16) in head lights (14, 15) is turned on. 5. In addition, current from fuse #19 in fuse box B (1) flows to column display controller (10) terminal #213 through high beam relay (17). 6. The input signal of terminal #2-13 is judged in column display controller (10). 7. Therefore, column display controller (10) turns on high beam indicator (19).

T2-5-34

SECTION 2 SYSTEM Group 5 Electrical System 20 1

2 S OFF H

(2)

3 1-25

2-13

6 (11)

(12)

11 b

(5) 13

(1) 17

(19)

TNDF-02-05-013

From Battery

From Battery Relay

123456-

Fuse Box B Light Switch Dimmer Switch Tail Light (Left) License Light (OPT) Clearance Light (Right)

7910111213-

Tail Light (Right) Clearance Light (Left) Column Display Controller Fuse Box A Head Light Relay (Left) Head Light Relay (Right)

141516171819-

f NOTE: The number in parentheses shows the fuse No. T2-5-35

Head Light (Left) Head Light (Right) High Beam High Beam Relay Clearance Light Indicator High Beam Indicator

20212223-

Clearance Light Position Head Light Position Low Beam Position High Beam Position

SECTION 2 SYSTEM Group 5 Electrical System Hazard Light Circuit (Key Switch: OFF) 1. Current (a) from the battery flows to hazard light switch (3) and flasher relay (2) through fuse #6 in fuse box B (1), and connects to the ground.

10. In addition, current which flows through turn signal light relay (4) blinks the indicator of hazard light switch (3).

2. Current from flasher relay (2) terminal L flows to right and left turn signal light relays (4, 5).

fNOTE: The hazard light circuit can be activated even if the key switch is in the OFF position.

3. When hazard light switch (3) is set to ON position (21), current from fuse #6 in fuse box B (1) flows to the coils in right and left turn signal light relays (4, 5) through hazard light switch (3), and connects to the ground. 4. Therefore, right and left turn signal light relays (4, 5) are turned ON. 5. When right and left turn signal light relays (4, 5) are turned ON, current from flasher relay (2) terminal L flows to all turn signal lights (6, 7, 8, and 9) through right and left turn signal light relays (4, 5) intermittently, and connects to the ground. 6. Therefore, all turn signal lights (6, 7, 8, and 9) blink. 7. At the same time, current from flasher relay (2) terminal L flows to terminals #2-15 and #2-14 in column display controller (10) intermittently. 8. Terminals #2-15 and #2-14 are connected to the ground in column display controller (10). 9. Therefore, column display controller (10) blinks right and left turn signal indicators (18, 19).

T2-5-36

SECTION 2 SYSTEM Group 5 Electrical System

1 a

(6) 20

2-15 2-14

12 11

L N R

16 9

(8) 17

TNED-02-05-014

ab-

From Battery From Fuse #12 in Fuse Box B

From Battery Relay

123456-

Fuse Box B Flasher Relay Hazard Light Switch Right Turn Signal Light Relay Left Turn Signal Light Relay Turn Signal Light (Right Front)

789101112-

Turn Signal Light (Right Rear) Turn Signal Light (Left Front) Turn Signal Light (Left Rear) Column Display Controller Turn Signal Lever Left-Hand Position

131415161718-

f NOTE: The number in parentheses shows the fuse No.

T2-5-37

Neutral Position Right-Hand Position Diode P Diode K Fuse Box A Right Turn Signal Light Indicator

19- Left Turn Signal Light Indicator 20- OFF Position 21- ON Position

SECTION 2 SYSTEM Group 5 Electrical System Turn Signal Light Circuit 9. At the same time, current from flasher relay (2) terminal L flows to terminal #2-14 in column display controller (10).

fNOTE: The operation with turn signal lever (11) set in left-hand position (12) is explained here.

1. Current (a) from the battery flows to flasher relay (2) through fuse #6 in fuse box B (1), and connects to the ground. 2. Current from flasher relay (2) terminal L flows to left turn signal light relay (5) and right turn signal light relay (4).

10. Terminal #2-14 is connected to the ground in column display controller (10). 11. Therefore, column display controller (10) blinks left turn signal light indicator (19).

fNOTE: When turn signal lever (11) is set in right-

3. When the key switch is in the ON position, current from the battery flows to fuse #8 in fuse box A (17) through the battery relay and the fusible link (140 A). 4. Current from fuse #8 in fuse box A (17) flows to turn signal lever (11). 5. When turn signal lever (11) is set in left-hand position (12), current from fuse #8 in fuse box A (17) flows to the coil in left turn signal light relay (5) through turn signal lever (11) and diode K (16), and connects to the ground. 6. Therefore, left turn signal light relay (5) is turned ON. 7. When left turn signal light relay (5) is turned ON, current from flasher relay (2) terminal L flows to left turn signal lights (8 and 9) at front and rear through left turn signal light relay (5) intermittently, and connects to the ground. 8. Therefore, left turn signal lights (8 and 9) at front and rear blink.

T2-5-38

hand position (14), right turn signal lights (6 and 7) at front and rear blink. At the same time, column display controller (10) blinks right turn signal light indicator (18).

SECTION 2 SYSTEM Group 5 Electrical System

1 a

(6) 20

2-15 2-14

12 11

L N R

16 9

(8) 17

TNED-02-05-015

ab-

From Battery From Fuse #8 in Fuse Box B

From Battery Relay

123456-

Fuse Box B Flasher Relay Hazard Light Switch Right Turn Signal Light Relay Left Turn Signal Light Relay Turn Signal Light (Right Front)

789101112-

Turn Signal Light (Right Rear) Turn Signal Light (Left Front) Turn Signal Light (Left Rear) Column Display Controller Turn Signal Lever Left-Hand Position

131415161718-

f NOTE: The number in parentheses shows the fuse No.

T2-5-39

Neutral Position Right-Hand Position Diode P Diode K Fuse Box A Right Turn Signal Light Indicator

19- Left Turn Signal Light Indicator 20- OFF Position 21- ON Position

SECTION 2 SYSTEM Group 5 Electrical System Horn Circuit (Key Switch: OFF) 1. Current (a) from the battery flows to horn relay (2) through fuse #5 in fuse box B (1). 2. When horn switches (3, 6) are pushed, current flowing to the coil in horn relay (2) connects to the ground. 3. Therefore, horn relay (2) is turned ON. 4. When horn relay (2) is turned ON, current from fuse #5 in fuse box B (1) operates horns (4, 5).

fNOTE: The horn circuit can be activated even if the key switch is in the OFF position.

T2-5-40

SECTION 2 SYSTEM Group 5 Electrical System

1 a

(5)

6 TNDB-02-05-016

From Battery

12-

Fuse Box B Horn Relay

34-

Horn Switch Horn (HIGH)

56-

f NOTE: The number in parentheses shows the fuse No.

T2-5-41

Horn (LOW) Horn Switch (Side)

SECTION 2 SYSTEM Group 5 Electrical System Reverse Buzzer Circuit 1. When the key switch is in the ON position, current (a) from the battery flows to fuse #7 in fuse box A (1) and fuse #10 in fuse box B (11) through the battery relay and the fusible link (100 A). 2. Current from fuse #7 in fuse box A (1) flows to back buzzer relay (2). 3. Current (b) from fuse #10 in fuse box B (11) flows to forward/reverse lever (7). 4. When forward/reverse lever (7) is set to reverse position (10), current from fuse #10 in fuse box B (11) flows to terminal #48 in HST controller (6) through forward/reverse lever (7). HST controller (6) connects terminals #48 and #5 in it. 5. Current from terminal #5 in HST controller (6) flows to the coil in back buzzer relay (2), and connects to the ground. 6. Therefore, back buzzer relay (2) is turned ON. 7. When back buzzer relay (2) is turned ON, current from fuse #7 in fuse box A (1) operates back buzzer (3).

fNOTE: HST stands for hydrostatic transmission.

T2-5-42

SECTION 2 SYSTEM Group 5 Electrical System

1 3

(7)

10 5

(10)

TNDF-02-05-022

From Battery Relay

123-

Fuse Box A Back Buzzer Relay Back Buzzer

678-

HST Controller Forward/Reverse Lever Forward Position

9- Neutral Position 10- Reverse Position 11- Fuse Box B

f NOTE: The number in parentheses shows the fuse No.

T2-5-43

SECTION 2 SYSTEM Group 5 Electrical System Brake Light Circuit 1. When the key switch is in the ON position, current from the battery flows to fuse #8 in fuse box A (1) through the battery relay and the fusible link (100 A). 2. Current from fuse #8 in fuse box A (1) flows to brake light relay (2). 3. When the brake pedal is operated, brake light switch (5) is turned ON. 4. When brake light switch (5) is turned ON, current from fuse #8 in fuse box A (1) flows to the coil in brake light relay (2), and connects to the ground. 5. Therefore, brake light relay (2) is turned ON. 6. When brake light relay (2) is turned ON, current from fuse #8 in fuse box A (1) flows to brake lights (3, 4) at both sides, and connects to the ground. 7. Therefore, brake lights (3, 4) at both sides are turned on.

T2-5-44

SECTION 2 SYSTEM Group 5 Electrical System

(8)

5 a-

From Battery Relay

12-

Fuse Box A Brake Light Relay

34-

Brake Light (Right) Brake Light (Left)

f NOTE: The number in parentheses shows the fuse No.

T2-5-45

Brake Light Switch

TNED-02-05-018

SECTION 2 SYSTEM Group 5 Electrical System Parking Brake Circuit Parking Brake: Released (Parking Brake Switch: Release Position (9)) IMPORTANT: The parking brake can be released only while the engine runs. 1. When the key switch is in the ON position, current (b) from terminal M flows to parking brake relay 1 (2) through fuse #14 in fuse box B (14). 2. Current (b) from parking brake relay 1 (2) (supply side) flows to terminal #4 in parking brake switch (3) through the coil in parking brake relay 2 (4). 3. When parking brake switch (3) is set to release position (9), parking brake switch (3) connects terminal #4 to terminal #6 in it. In addition, terminal #6 is connected to the ground. 4. Therefore, parking brake relay 2 (4) is turned ON.

9. When parking brake switch (3) with it set in release position (9) is released, it returns to neutral position (10). 10. Therefore, the circuit to the ground from terminal #4 in parking brake switch (3) and parking brake relay 2 (4) (supply side) is disconnected. However, as the self-exciting circuit is formed in parking brake relay 2 (4), parking brake solenoid valve (6) continues to be operated. 11. Consequently, parking brake solenoid valve (6) continues to be operated until parking brake switch (3) is set to Apply position (11). 12. Terminal #2-25 of column display controller (1) receives the signal from pressure sensor (parking brake) (12).

5. When parking brake relay 2 (4) is turned ON, current (d) from fuse #10 in fuse box A (8) flows to the ground through parking brake relay 2 (4) (supply side).

13. The input signal of terminal #2-25 is judged in column display controller (1). Then, column display controller (1) puts out parking brake indicator (13).

6. Therefore, current flows to parking brake solenoid valve (6) and activates it.

fNOTE: Parking brake switch (3) is a three position

switch which has release position (9), neutral position (10), and apply position (11). When parking brake switch set in apply position (11), it stay in apply position (11). When parking brake switch (3) is set in release position (9) and released, it returns to neutral position (10).

7. At the same time, current (b) which flows through the coil of parking brake relay 2 (4) flows to parking brake relay 2 (4) (supply side) through diode G (5), and flows to the ground. Therefore, the self-exciting circuit is formed by parking brake relay 2 (4). 8. Therefore, pilot pressure oil from parking brake solenoid valve (6) is supplied to the parking brake and releases it. (Refer to SYSTEM / Hydraulic System.)

fNOTE: As pressure oil from the pilot pump (parking

brake release pressure oil) is not supplied to the parking brake with the engine stopped, the parking brake is applied by the spring force. Therefore, the parking brake can not be released with the engine stopped.

T2-5-46

SECTION 2 SYSTEM Group 5 Electrical System

13 2

2-3 2-25 2-4

14 b

9 10 11

a 1 2 3 4 5 6 9

(14) 7

8 d

(10) 6 5

4 TNDF-02-05-019

To Information Controller (Terminal D13)

bc-

From Key Switch Terminal M From Fuse Box B (Fuse #12)

From Battery Relay

1234-

Column Display Controller Parking Brake Relay 1 Parking Brake Switch Parking Brake Relay 2

5678-

Diode G Parking Brake Solenoid Valve Diode F Fuse Box A

9101112-

Release Position Neutral Position Apply Position Pressure Sensor (Parking Brake)

f NOTE: The number in parentheses shows the fuse No.

T2-5-47

13- Parking Brake Indicator 14- Fuse Box B

SECTION 2 SYSTEM Group 5 Electrical System Parking Brake: Applied (Parking Brake Switch: Apply Position (11)) 1. When the key switch is in the ON position, current (b) from terminal M flows to parking brake relay 1 (2) through fuse #14 in fuse box B (14).

9. Terminal #2-25 of column display controller (1) receives the signal from pressure sensor (parking brake) (12).

2. Current (b) which flows to the coil side of parking brake relay 1 (2) flows to terminal #1 in parking brake switch (3).

10. The input signal of terminal #2-25 is judged in column display controller (1). Then, column display controller (1) turns on parking brake indicator (13).

3. When parking brake switch (3) is set to Apply position (11) while the engine runs, terminal #1 in parking brake switch (3) is connected to the ground. 4. Therefore, parking brake relay 1 (2) is turned ON. 5. When parking brake relay 1 (2) is turned ON, current (b) in the circuit to the ground from parking brake relay 1 (2) (supply side) and parking brake relay 2 (4) (supply side) stops flowing. 6. Therefore, parking brake relay 2 (4) is turned OFF. 7. When parking brake relay 2 (4) is turned OFF, current (b) which flows to parking brake solenoid valve (6) stops flowing. Then, parking brake solenoid valve (6) is stopped. 8. Therefore, as pilot pressure oil in the parking brake is returned to the hydraulic oil tank, the parking brake is applied. (Refer to SYSTEM / Hydraulic System.)

T2-5-48

SECTION 2 SYSTEM Group 5 Electrical System

13 2

2-3 2-25 2-4

14 b

9 10 11

a 1 2 3 4 5 6 9

(14) 7

8 d

(10) 6 5

4 TNDF-02-05-020

To Information Controller (Terminal D13)

bc-

From Key Switch Terminal M From Fuse Box B (Fuse #12)

1234-

Column Display Controller Parking Brake Relay 1 Parking Brake Switch Parking Brake Relay 2

5678-

Diode G Parking Brake Solenoid Valve Diode F Fuse Box A

9- Release Position 10- Neutral Position 11- Apply Position

f NOTE: The number in parentheses shows the fuse No.

T2-5-49

From Battery Relay

12- Pressure Sensor (Parking Brake) 13- Parking Brake Indicator 14- Fuse Box B

SECTION 2 SYSTEM Group 5 Electrical System (Blank)

T2-5-50

SECTION 2 SYSTEM Group 5 Electrical System Accessory Circuit The major functions and circuits in the accessory circuit are as follows.  Work Light Circuit: Turns on the work light. (Work Light Switch, Work Light Relay)  Wiper Circuit: Operates the intermittent operation of wiper and the washer. (Column Display Controller, Wiper/Washer Switch, Wiper Relay, Washer Relay)  Cab Light Circuit: Turns on/off the cab light by shifting the switch or by opening/closing the door.

T2-5-51

SECTION 2 SYSTEM Group 5 Electrical System Work Light Circuit

fNOTE: When work light switch (4) is set to ON 1 position

fNOTE: The operation with work light switch (4) set in

(13), work lights (7, 8, 9, and 10) at front and rear are turned on.

ON 2 position (11) is explained here. 1. When the key switch is in the ON position, current from the battery flows to fuse #4 in fuse box A (3) and fuse #17 in fuse box B (1) through the battery relay and the fusible link (100 A). 2. Current from fuse #4 in fuse box A (3) flows to work light (front) relay (5). In addition, current from fuse #17 in fuse box B (1) flows to work light (rear) relay (6). 3. When light switch (2) is set to clearance light position (14), current from fuse #2 in fuse box B (1) flows to terminal #1 and terminal #4 in work light switch (4). 4. When work light switch (4) is set to ON 2 position (11), current from fuse #2 in fuse box B (1) flows to the coil in work light (front) relay (5) through terminals #1 and #3 in work light switch (4), and connects to the ground. 5. Therefore, work light (front) relay (5) is turned ON. 6. When work light (front) relay (5) is turned ON, current from fuse #4 in fuse box A (3) turns on work light (front, right) (7) and work light (front, left) (8). 7. At the same time, current from fuse #4 in fuse box A (3) flows to terminal #2-12 in column display controller (17). Terminal #2-12 is connected to the ground in column display controller (17). 8. Therefore, column display controller (17) turns on work light indicator (16). 9. In addition, current from fuse #12 in fuse box B (1) flows to terminal #8 in work light switch (4) and turns on the indicator.

T2-5-52

SECTION 2 SYSTEM Group 5 Electrical System

S OFF H a

(4)

ON2 OFF ON1

(12)

7 8

1 2 3 4 5 6 8 9

2-12

11 12 13

(2)

9 10

(17) 1

TNED-02-05-021

From Battery

From Battery Relay

12345-

Fuse Box B Light Switch Fuse Box A Work Light Switch Work Light (Front) Relay

678910-

Work Light (Rear) Relay Work Light (Front, Right) Work Light (Front, Left) Work Light (Rear, Right) Work Light (Rear, Left)

1112131415-

f NOTE: The number in parentheses shows the fuse No.

T2-5-53

ON 2 Position OFF Position ON 1 Position Clearance Light Position Head Light Position

16- Work Light Indicator 17- Column Display Controller

SECTION 2 SYSTEM Group 5 Electrical System Wiper Circuit Front Wiper Circuit

fNOTE: The operation with front wiper/washer switch

(8) set in INT. position (15) is explained here. 1. When the key switch is in the ON position, current from the battery flows to fuse #3 in fuse box A (1) through the battery relay and fusible link (100 A). 2. Current from fuse #3 in fuse box A (1) flows to terminal #2-19 in column display controller (14) through the coil in front wiper relay 1 (5). 3. When front wiper/washer switch (8) is set to INT. position (15), current from column display controller (14) terminal #1-20 flows to terminal #1 through terminal #7 in front wiper/washer switch (8), and connects to the ground. 4. When terminal #1-20 in column display controller (14) is connected to the ground, column display controller (14) connects terminal #2-19 to the ground in it intermittently. 5. Therefore, front wiper relay 1 (5) is turned ON or OFF repeatedly. 6. When front wiper relay 1 (5) is turned ON, current (c) from fuse #3 in fuse box A (1) flows to front wiper relay 1 (5) through slow speed circuit (18) in front wiper motor (3) and front wiper relay 2 (4), and connects to the ground. 7. Therefore, the front wiper is operated at slow speed and intermittently.

T2-5-54

SECTION 2 SYSTEM Group 5 Electrical System

1 c

(3)

6 8 17 9 2-18

a b

2-19 1-34

1-20 1-29 1-30

2 c

(18)

13 TNED-02-05-022

From Front Wiper Relay 2

From Front Wiper Relay 1

From Battery Relay

12345-

Fuse Box A Fuse Box B Front Wiper Motor Front Wiper Relay 2 Front Wiper Relay 1

678910-

Front Washer Motor Front Washer Relay Front Wiper/Washer Switch Rear Wiper/Washer Switch Rear Wiper Motor

1112131415-

Rear Washer Motor Rear Wiper Relay Rear Washer Relay Column Display Controller INT. Position

f NOTE: The number in parentheses shows the fuse No. T2-5-55

16171819-

LOW Position Washer Position Slow Speed Circuit Fast Speed Circuit

SECTION 2 SYSTEM Group 5 Electrical System Rear Wiper Circuit

fNOTE: The operation with rear wiper/washer switch (9) set in LOW position (16) is explained here. 1. When rear wiper/washer switch (9) is set to LOW position (16), terminal #9 is connected to terminal #1.

2. When the key switch is in the ON position, current from the battery flows to fuse #18 in fuse box B (2) through the battery relay and fusible link (100 A). 3. Current (c) from fuse #18 in fuse box B (2) flows to terminal #9 in rear wiper/washer switch (9) through the coil in rear wiper relay (12), and connects to the ground. 4. Therefore, rear wiper relay (12) is turned ON. 5. When rear wiper relay (12) is turned ON, current (c) from fuse #18 in fuse box B (2) flows to rear wiper motor (10) and operated the rear wiper at slow speed.

T2-5-56

SECTION 2 SYSTEM Group 5 Electrical System

1 c

(3)

6 8 17 9 2-18

a b

2-19 1-34

1-20 1-29 1-30

2 c

(18)

13 TNED-02-05-023

From Front Wiper Relay 2

From Front Wiper Relay 1

From Battery Relay

12345-

Fuse Box A Fuse Box B Front Wiper Motor Front Wiper Relay 2 Front Wiper Relay 1

678910-

Front Washer Motor Front Washer Relay Front Wiper/Washer Switch Rear Wiper/Washer Switch Rear Wiper Motor

1112131415-

Rear Washer Motor Rear Wiper Relay Rear Washer Relay Column Display Controller INT. Position

f NOTE: The number in parentheses shows the fuse No. T2-5-57

16- LOW Position 17- Washer Position

SECTION 2 SYSTEM Group 5 Electrical System Washer Circuit

fNOTE: The operation of front washer is explained here. 1. Current (c) from fuse #3 in fuse box A (1) flows to the coil in front washer relay (7), flows to terminal #6 in front wiper/washer switch (8) through diode H (20). 2. While washer position (17) of front wiper/washer switch (8) is pushed, current from column display controller (14) terminal #1-34 connects terminals #6 and #1 to the ground in front wiper/washer switch (8). 3. Therefore, front washer relay (7) is turned ON. 4. When front washer relay (7) is turned ON, current from fuse #3 in fuse box A (1) flows to front washer motor (6) and operates the front washer.

fNOTE: The front wiper motor is activated at the same time.

T2-5-58

SECTION 2 SYSTEM Group 5 Electrical System

1 c

(3)

6 20 8 17 9 2-18

a b

2-19 1-34

1-20 1-29 1-30

2 c

(18)

13 TNED-02-05-024

From Front Wiper Relay 2

From Front Wiper Relay 1

From Battery Relay

12345-

Fuse Box A Fuse Box B Front Wiper Motor Front Wiper Relay 2 Front Wiper Relay 1

678910-

Front Washer Motor Front Washer Relay Front Wiper/Washer Switch Rear Wiper/Washer Switch Rear Wiper Motor

1112131415-

Rear Washer Motor Rear Wiper Relay Rear Washer Relay Column Display Controller INT. Position

f NOTE: The number in parentheses shows the fuse No.

T2-5-59

16- LOW Position 17- Washer Position 20- Diode H

SECTION 2 SYSTEM Group 5 Electrical System Cab Light Circuit Cab Light Switch (4): Door Interlocking Position (5)

Rear Cab Light Switch (8): ON

1. When cab light switch (4) is set to door interlocking position (5), current (a) from fuse #3 in fuse box B (1) flows to door open/close switch (3) through cab light (2).

1. When rear cab light switch (8) is set to the ON position, current (a) from fuse #3 in fuse box B (1) flows to rear cab light (7), and connects to the ground.

2. When the cab door is opened, door open/close switch (3) is turned ON and is connected to the ground.

2. Consequently, rear cab light (7) is always on with rear cab light switch (8) set in the ON position.

3. Therefore, current (a) from fuse #3 in fuse box B (1) flows to door open/close switch (3) and turns on cab light (2). 4. When the cab door is shut, door open/close switch (3) is turned OFF and is disconnected from the ground. 5. Therefore, cab light (2) is tuned off. 6. Consequently, when cab light switch (4) is in door interlocking position (5), cab light (2) is turned on/ off by opening/closing the cab door.

fNOTE: Consequently, cab light (2) is always on with cab light switch (4) set in ON position (6).

T2-5-60

SECTION 2 SYSTEM Group 5 Electrical System

1 a

From Battery

12-

Fuse Box B Cab Light

(3)

34-

Door Open/Close Switch Cab Light Switch

56-

f NOTE: The number in parentheses shows the fuse No.

T2-5-61

Door Interlocking Position ON Position

TNED-02-05-025

78-

Rear Cab Light Rear Cab Light Switch

SECTION 2 SYSTEM Group 5 Electrical System (Blank)

T2-5-62

SECTION 3

COMPONENT OPERATION CONTENTS Group 1 Pump Device

Outline..................................................................................... T3-1-1 HST Pump Layout........................................................... T3-1-2 Pump Circuit Diagram.................................................. T3-1-3 Rotary Group......................................................................... T3-1-4 Displacement Angle Control Cylinder.......................... T3-1-6 Recovery Moment Function....................................... T3-1-8 Pump Displacement Angle Control Solenoid Valve..................................................................................T3-1-10 Constant Torque Control...........................................T3-1-12 Forward/Reverse Control Solenoid Valve .................T3-1-14 Cutoff Valve..........................................................................T3-1-16 High-Pressure Relief Valve..............................................T3-1-18 Low-Pressure Relief Valve................................................T3-1-18 Bypass Function............................................................T3-1-20 HST Charging Pump..........................................................T3-1-22 4-Gear Pump Unit..............................................................T3-1-23

Group 2 HST Motor

Outline..................................................................................... T3-2-1 HST Motor Layout.......................................................... T3-2-2 Rotary Group......................................................................... T3-2-4 Regulator................................................................................ T3-2-6 Motor Displacement Angle Control Solenoid Valve.................................................................................... T3-2-7 Motor Displacement Angle Control.............................. T3-2-8 Flushing Valve.....................................................................T3-2-12

Group 3 Multiple Control Valve

Outline..................................................................................... T3-3-1 Multiple Control Valve.................................................. T3-3-1 Multiple Control Valve Hydraulic Diagram............ T3-3-2 Layout of Multiple Control Valve.............................. T3-3-3 Hydraulic Circuit................................................................... T3-3-6 Main Circuit...................................................................... T3-3-6 Main Relief Valve.................................................................. T3-3-8 Overload Relief Valve........................................................T3-3-10 Overload Relief Valve for Bucket Dump Circuit..........................................................................T3-3-10 Overload Relief Valve for Lift Arm Raise and Bucket Roll Back Circuits.......................................T3-3-14 Make-Up Valve....................................................................T3-3-16 Flow Rate Control Valve...................................................T3-3-18 Pilot Operation Control Circuit................................T3-3-20 Slow Return Valve.........................................................T3-3-20 Lift Arm Float Control.................................................T3-3-22

External Pilot Pressure Circuit..................................T3-3-24 Exhaust Filter Regeneration Circuit.......................T3-3-24 Quick Coupler Circuit (Option)................................T3-3-26

Group 4 Fan Motor and Fan Valve

Fan Motor............................................................................... T3-4-1 Fan Valve................................................................................. T3-4-3 Operation (Fan Speed Control)................................. T3-4-4 Fan Valve (with Fan Reverse Rotation)......................... T3-4-7 Operation.......................................................................... T3-4-8 Make-Up Operation.....................................................T3-4-14

Group 5 Steering Valve

Outline..................................................................................... T3-5-1 Structure................................................................................. T3-5-2 Operation................................................................................ T3-5-3 Steering (Left).................................................................. T3-5-4 Steering (Right)............................................................... T3-5-5 Neutral................................................................................ T3-5-5 Overload Relief Valve.......................................................... T3-5-6 Make-Up Valve...................................................................... T3-5-8

Group 6 Priority Valve

Outline..................................................................................... T3-6-1 Structure................................................................................. T3-6-2 Operation................................................................................ T3-6-4 When steering is in neutral......................................... T3-6-4 When steering is operated.......................................... T3-6-6 When steering cylinder is at stroke end................. T3-6-8

Group 7 Pilot Valve

Outline (Joystick Type Pilot Valve for Front Attachment)..................................................................... T3-7-1 Operation................................................................................ T3-7-2 Electromagnetic Detent..................................................T3-7-10 Outline (Fingertip Control Type Pilot Valve for Front Attachment).......................................................T3-7-11 Operation..............................................................................T3-7-12 Electromagnetic Detent..................................................T3-7-16 Outline (Auxiliary Pilot Valve) (Option)......................T3-7-17 Operation..............................................................................T3-7-18 Outline (Auxiliary Pilot Valve) (Option)......................T3-7-23 Operation..............................................................................T3-7-24

Group 8 Brake Charge Valve

Outline..................................................................................... T3-8-1 Brake Charge Valve.............................................................. T3-8-2 62Z7/67Z7/67TM7 (OCE)

Group 9 Manifold Valve

Outline..................................................................................... T3-9-1 Manifold Valve....................................................................... T3-9-2 Pilot Reducing Valve........................................................... T3-9-4 Parking Brake Solenoid Valve.......................................... T3-9-6 Control Lever Lock Solenoid Valve................................ T3-9-8 Pilot Accumulator .............................................................T3-9-10

Group 10 Transmission

Outline...................................................................................T3-10-1 Transmission Hydraulic Circuit Diagram..............T3-10-2 Layout of Transmission...............................................T3-10-3 Clutch Shaft Part...........................................................T3-10-4 Clutch Pressure Control Solenoid Valve...............T3-10-5 Power Transmission...........................................................T3-10-6 Power Transmission (At Slow Speed)....................T3-10-6 Power Transmission (At Fast Speed)......................T3-10-7 Clutch Operation................................................................T3-10-8 Clutch Pressure Control Solenoid Valve.................. T3-10-10 Regulator...................................................................... T3-10-12 Proportional Solenoid Valve.................................. T3-10-14 Parking Brake.................................................................... T3-10-16

Solenoid Valve.....................................................................T3-14-7 Exhaust Filter Regeneration Control Solenoid Valve.............................................................................T3-14-8 Quick Coupler Pilot Solenoid Valve (Option)......T3-14-9 Coupler Cylinder Selector Solenoid Valve (Option).................................................................... T3-14-10 Filter..................................................................................... T3-14-12 Bucket Regenerative Selector Valve......................... T3-14-13 Bucket Regenerative Valve.......................................... T3-14-14

Group 11 Axle

Outline...................................................................................T3-11-1 Differential............................................................................T3-11-2 Purpose of Differential................................................T3-11-3 Principle of Differential...............................................T3-11-4 Operation of Differential............................................T3-11-5 Torque Proportioning Differential (TPD)...................T3-11-6 Limited Slip Differential (LSD).......................................T3-11-8 Service Brake.................................................................... T3-11-10 Final Drive Planetary / Axle Shaft.............................. T3-11-12

Group 12 Brake Valve

Outline...................................................................................T3-12-1 Brake Valve Hydraulic Circuit Diagram.................T3-12-1 Operation..............................................................................T3-12-4

Group 13 Ride Control Valve

Outline...................................................................................T3-13-1 Ride Control Hydraulic Circuit Diagram...............T3-13-2 Operation........................................................................T3-13-4 Charge-Cut Spool..............................................................T3-13-6 Overload Relief Valve........................................................T3-13-8 Make-Up Operation.................................................. T3-13-10 Drain Plug.......................................................................... T3-13-12

Group 14 Others

Propeller Shaft....................................................................T3-14-1 HST Cooler Bypass Check Valve....................................T3-14-2 Service Brake Accumulator ...........................................T3-14-3 Steering Accumulator......................................................T3-14-3 Ride Control Accumulator (Option)............................T3-14-4 Secondary Steering Check Block (Option)................T3-14-5 Secondary Steering Pump (Option)............................T3-14-6

62Z7/67Z7/67TM7 (OCE)

SECTION3 COMPONENT OPERATION Group 1 Pump Device Outline HST (hydrostatic transmission) pump (1) is a twodirection displacement angle swash plate type variable displacement plunger pump. HST pump (1) consists of shaft (2), the plunger, the cylinder block, the displacement angle control cylinder, and the swash plate. (Refer to Rotary Group and Displacement Angle Control Cylinder.) The forward/reverse control solenoid valve, the pump displacement angle control solenoid valve, the cutoff valve, the high-pressure relief valve, the low-pressure relief valve, the HST charging pump, HST circuit pressure 1 sensor, and HST circuit pressure 2 sensor are provided in order to control HST pump (1). (Refer to HST Pump Layout.) Driving force of the engine is transmitted to shaft (2) of HST pump (1) through coupling (4). In addition, the shaft (2) rotation of HST pump (1) is transmitted to 4-gear pump unit (6) through coupling (5). 1

From Engine

12-

HST Pump Shaft

34-

Engine Flywheel Coupling

TNDF-03-01-001

56-

T3-1-1

Coupling 4-Gear Pump Unit

SECTION3 COMPONENT OPERATION Group 1 Pump Device HST Pump Layout 2

11, 17

6 7 16

View A

12, 18 View B TNDF-03-01-002

123-

HST Pump Pump Displacement Angle Control Solenoid Valve Forward/Reverse Control Solenoid Valve

45678-

Displacement Angle Control Cylinder Cutoff Valve High-Pressure Relief Valve Shuttle Valve Low-Pressure Relief Valve

91011121314-

T3-1-2

Port T1 Port B (Forward Side Output) Port MB Port MA Port A (Reverse Side Output) HST Charging Pump

15161718-

Port Fe Port Fa HST Circuit Pressure 1 Sensor HST Circuit Pressure 2 Sensor

SECTION3 COMPONENT OPERATION Group 1 Pump Device Pump Circuit Diagram 2

17 7

5 16

14 ENG

12 9

18 TNDF-03-01-003

Forward Side Solenoid Valve

Reverse Side Solenoid Valve

To 4-Gear Pump Unit

12-

HST Pump Pump Displacement Angle Control Solenoid Valve Forward/Reverse Control Solenoid Valve

Displacement Angle Control Cylinder Cutoff Valve High-Pressure Relief Valve Shuttle Valve Low-Pressure Relief Valve

91011121314-

Port T1 Port B (Forward Side Output) Port MB Port MA Port A (Reverse Side Output) HST Charging Pump

5678-

T3-1-3

151617181920-

Port Fe Port Fa HST Circuit Pressure 1 Sensor HST Circuit Pressure 2 Sensor HST Charge Oil Filter Hydraulic Oil Tank

SECTION3 COMPONENT OPERATION Group 1 Pump Device Rotary Group Operation: 1. Shaft (1) is connected to cylinder block (5) by spline joint. Plunger (4) is inserted into cylinder block (5). 2. Driving force of the engine is transmitted to shaft (1) of the HST pump through the coupling. When shaft (1) is rotated, plunger (4) rotates with cylinder block (5) together. 3. Plunger (4) slides on shoe plate (3) and reciprocates in the cylinder block (5) bore due to inclination of swash plate (2). 4. By this reciprocation, hydraulic oil is drawn and delivered. 5. Either port A (8) or port B (7) is selected as the output port by the displacement angle control of swash plate (2) in displacement angle control cylinder (6).

T3-1-4

SECTION3 COMPONENT OPERATION Group 1 Pump Device 6

123-

Shaft Swash Plate Shoe Plate

45-

Plunger Cylinder Block

67-

T3-1-5

TNDF-03-01-004

Displacement Angle Control Cylinder Port B (Forward Side Output)

Port A (Reverse Side Output)

SECTION3 COMPONENT OPERATION Group 1 Pump Device Displacement Angle Control Cylinder Changing displacement angle (a) of swash plate (4) causes stroke (b) of plunger (6) to increase or decrease in order to increase or decrease the HST pump delivery flow rate. Operation: 1. As swash plate (4) is connected to displacement angle piston (2) of displacement angle control cylinder (1) through guide (3), swash plate (4) is operated according to the movement of displacement angle piston (2). 2. Displacement angle piston (2) has built-in spring (5), which acts on the direction to return displacement angle piston (2) to the neutral position. 3. The position of displacement angle piston (2) is moved by displacement angle control pressure (P) which is supplied to displacement angle control cylinder (1) through pump displacement angle control solenoid valve (7) and forward/reverse control solenoid valve (8). 4. Therefore, displacement angle (a) of swash plate (4) is changed so that the delivery flow rate is changed.

f NOTE: The illustration shows the oil flow while driving in forward direction.

T3-1-6

SECTION3 COMPONENT OPERATION Group 1 Pump Device

TNDF-03-01-005

TNDF-03-01-006

Displacement Angle

P-

Displacement Angle Control Pressure

bc-

Plunger Stroke Suction

Output

Displacement Angle Control Cylinder Displacement Angle Piston

345-

Guide Swash Plate Spring

67-

Plunger Pump Displacement Angle Control Solenoid Valve

Forward/Reverse Control Solenoid Valve

T3-1-7

SECTION3 COMPONENT OPERATION Group 1 Pump Device Recovery Moment Function X and Y are the ranges of pressurized oil which is supplied to plunger (6) through valve plate (9). The comparison between X and Y causes swash plate (4) to return the neutral position in proportion to the circuit pressure. Operation: 1. The pressure from the HST motor is routed to the plunger (6) inside of the HST pump. 2. As there is a difference between X and Y of valve plate (9), the pressurized oil force routed to plunger (6) through Y is higher than that through X. 3. Plunger (6) pushes the bottom of swash plate (4) as moment around displacement angle center (g). Then, swash plate (4) is moved toward the neutral position. This is the recovery moment function. 4. Displacement angle (a) of swash plate (4) decreases in proportion to the pressure in the HST circuit between HST pump and HST motor. 5. When the HST circuit pressure is low, the moving angle of displacement angle (a) is small. When the HST circuit pressure is high, the moving angle is large.

T3-1-8

SECTION3 COMPONENT OPERATION Group 1 Pump Device

TNDF-03-01-005

TNDF-03-01-007

ac-

Displacement Angle Suction

de-

Output Low-Pressure Side Port

fg-

High-Pressure Side Port Displacement Angle Center

Swash Plate

Plunger

Valve Plate

T3-1-9

SECTION3 COMPONENT OPERATION Group 1 Pump Device Pump Displacement Angle Control Solenoid Valve 1

Pump displacement angle control solenoid valve (2) is shifted by signal (c) from the HST controller and supplies pilot pressurized oil to control displacement angle control cylinder (4). Pump displacement angle control solenoid valve (2) is a proportional solenoid valve.

Operation: 1. Pump displacement angle control solenoid valve (2) is controlled by current signal (c) from the HST controller and outputs the pressure in proportion to current signal (c). 2. Therefore, it reduces the oil output pressure from HST charging pump (14) and changes control pressure (P) of displacement angle control cylinder (4). 3. Consequently, the pressure almost in proportion to actual engine speed (N) is supplied to displacement angle control cylinder (4).

N TNDF-02-02-066 N-

Actual Engine Speed

Q-

Pump Displacement Angle (%)

Power Mode OFF

Power Mode ON

4. Therefore, pump displacement angle (Q) is changed so that the delivery flow rate is controlled.

f NOTE: Pilot pressurized oil from pump displacement

angle control solenoid valve (2) is supplied to forward/ reverse control solenoid valve (3) and the output direction of pressurized oil is controlled.

f NOTE: The output characteristics of actual engine

speed (N) and pump displacement angle control solenoid valve (32) are different depending on the power mode ON/OFF. (the drawings on the right)

T3-1-10

SECTION3 COMPONENT OPERATION Group 1 Pump Device

3 19

14 ENG

8 TNDF-03-01-008

Input Signal from HST Controller

Pump Displacement Angle Control Solenoid Valve

Forward/Reverse Control Solenoid Valve

45-

T3-1-11

Displacement Angle Control Cylinder Cutoff Valve

8- Low-Pressure Relief Valve 14- HST Charging Pump 19- HST Charge Oil Filter

SECTION3 COMPONENT OPERATION Group 1 Pump Device Constant Torque Control The constant torque control prevents the engine stop due to overloading by using control pressure (P) of displacement angle control cylinder (4) generated in pump displacement angle control solenoid valve (2) for the pump displacement angle control.

T a

Operation: 1. When the engine is loaded and the engine speed decreases, the pump displacement angle control solenoid valve (2) reduces control pressure (P) of displacement angle control cylinder (4). 2. Therefore, as the pump displacement angle is changed, the pump displacement is reduced and pump torque (b) is also reduced. The pump displacement is balanced with engine torque (a). 3. When the engine load is increased, engine speed (N) is slightly decreased and the HST controller automatically performs the pump displacement angle control.

Pmax

N N'

TNP-

Torque Engine Speed Control Pressure

ab-

Engine Torque Pump Torque

4. Consequently, engine torque (a) can be utilized more efficiently without the engine stop.

T3-1-12

T81S-03-01-011

Pmax- Overloading State P3- Stable State

SECTION3 COMPONENT OPERATION Group 1 Pump Device

3 19

14 ENG

8 TNDF-03-01-008

Input Signal from HST Controller

Pump Displacement Angle Control Solenoid Valve

Forward/Reverse Control Solenoid Valve

45-

T3-1-13

Displacement Angle Control Cylinder Cutoff Valve

8- Low-Pressure Relief Valve 14- HST Charging Pump 19- HST Charge Oil Filter

SECTION3 COMPONENT OPERATION Group 1 Pump Device Forward/Reverse Control Solenoid Valve Forward/reverse control solenoid valve (3) controls the pump displacement angle direction and changes the output direction (forward or reverse) of pressurized oil. Operation: 1. Pilot pressurized oil (d) for the displacement angle control cylinder (4) control from pump displacement angle control solenoid valve (2) is routed to forward/reverse control solenoid valve (3). 2. The HST controller receives the signal from the forward/reverse lever or forward/reverse switch. The HST controller sends the signal to forward/reverse control solenoid valve (3). (Refer to Control System / Forward/Reverse Selection Control.) 3. Forward/reverse control solenoid valve (3) excites forward side solenoid valve (a) or reverse side solenoid valve (b) according to input signal (c) from the HST controller, and activates the spool. 4. Forward/reverse control solenoid valve (3) connects the hydraulic circuit to displacement angle control cylinder (4) according to the spool movement and supplies pilot pressurized oil (d) to displacement angle control cylinder (4). 5. Therefore, it controls the pump displacement angle direction and changes the output direction (port B (forward side output) (10) or port A (reverse side output) (13)) of pressurized oil.

T3-1-14

SECTION3 COMPONENT OPERATION Group 1 Pump Device

5 10

14 ENG

8 TNDF-03-01-009

ab-

Forward Side Solenoid Valve Reverse Side Solenoid Valve

Input Signal from HST Controller

Pilot Pressurized Oil

Pump Displacement Angle Control Solenoid Valve Forward/Reverse Control Solenoid Valve

Displacement Angle Control Cylinder Cutoff Valve Shuttle Valve

8101314-

Low-Pressure Relief Valve Port B (Forward Side Output) Port A (Reverse Side Output) HST Charging Pump

57-

f NOTE: The illustration shows the oil flow while driving in forward direction.

T3-1-15

19- HST Charge Oil Filter

SECTION3 COMPONENT OPERATION Group 1 Pump Device Cutoff Valve Cutoff valve (5) regulates the maximum circuit pressure and protects the circuit on the high-pressure side. Highpressure relief valve (6) functions as a safety valve and cutoff valve (5) regulates the circuit pressure on the highpressure side. Therefore, the set pressure of cutoff valve (5) is lower than that of high-pressure relief valve (6). Operation: 1. When the high-pressure side in the travel circuit reaches the specified circuit pressure, the control pressure which is routed to displacement angle control cylinder (4) through pump displacement angle control solenoid valve (2) is reduced. 2. When the control pressure of displacement angle control cylinder (4) is reduced, the pump displacement angle is controlled in order to deliver the pressurized oil flow rate corresponding to the pump specified pressure.

27 26 21 24 28 25 22 24 a d

23 c

From HST Charging Pump (Pilot Pressurized Oil)

21- Lock Screw 22- Sleeve

From Shuttle Valve (HST Circuit Pressure)

23- Piston 24- Spring Seat

TNDF-03-01-018 c-

Into Case

25- Spring 26- Hexagon Nut

T3-1-16

To Pump Displacement Angle Control Solenoid Valve

27- Adjusting Screw 28- O-Ring

SECTION3 COMPONENT OPERATION Group 1 Pump Device

5 10

14 ENG

TNDF-03-01-010

Forward Side Solenoid Valve

Reverse Side Solenoid Valve

Pump Displacement Angle Control Solenoid Valve Forward/Reverse Control Solenoid Valve

Displacement Angle Control Cylinder Cutoff Valve High-Pressure Relief Valve

56-

781013-

f NOTE: The illustration shows the oil flow while driving in forward direction.

T3-1-17

Shuttle Valve Low-Pressure Relief Valve Port B (Forward Side Output) Port A (Reverse Side Output)

14- HST Charging Pump 19- HST Charge Oil Filter

SECTION3 COMPONENT OPERATION Group 1 Pump Device High-Pressure Relief Valve It regulates the maximum circuit pressure in the travel circuit and protects high-pressure side circuit (a). In addition, it has the check valve function for HST charging. When the pressurized oil flow rate to suction side circuit (b) is insufficient, pressurized oil from HST charging pump (14) is routed to suction side circuit (b).

Low-Pressure Relief Valve It regulates the output pressure from HST charging pump (14). It is always operated during machine operation. The relieved oil flows to the drain (20) in the pump case for lubrication and cooling.

21- Lock Screw 22- Valve Piston

23- Spring Seat 24- Spring

TNDF-03-01-017

25- O-Ring 26- Shim (3 Used)

f NOTE: The illustration shows the low-pressure relief valve.

T3-1-18

27- Seal Ring

SECTION3 COMPONENT OPERATION Group 1 Pump Device

14 ENG

13 b

8 TNDF-03-01-011

Travel Circuit (High-Pressure Side in Forward)

Travel Circuit (Low-Pressure Side in Forward)

68-

High-Pressure Relief Valve Low-Pressure Relief Valve

10- Port B (Forward Side Output) 13- Port A (Reverse Side Output)

14- HST Charging Pump 20- Drain in Pump Case

f NOTE: The illustration shows the oil flow while driving in forward direction.

T3-1-19

SECTION3 COMPONENT OPERATION Group 1 Pump Device Bypass Function Only when there is no mechanical troubles in the HST circuit, the machine can be towed in emergency. Port A (reverse side output) is connected to Port B (forward side output) by loosening shuttle valve (7). Then, the machine can be towed. When the machine is towed fast, dCAUTION: heating the component causes insufficient

lubrication so that it is damaged. This function can be used only when the machine is towed slowly and in short distance in emergency.

f NOTE: Forcibly release the parking brake before the machine is also required when towing machine in emergency. (Refer to Transmission.)

Procedure: IMPORTANT: Set the machine position for inspection and maintenance. (Refer to the separated volume, Operator’s Manual.) 1. Turn the key switch OFF and stop the engine. 2. Loosen shuttle valve (7) until it comes in contact with stopper (a). l : 8 mm (0.31 in) 3. The bypass function becomes effective. 4. When the machine towing is completed, tighten shuttle valve (7) to the original position. l : 8 mm (0.31 in) m : 50 N·m (5 kgf/m, 37 lbf·ft)

TNDF-03-01-013 a-

Stopper

Shuttle Valve

T3-1-20

SECTION3 COMPONENT OPERATION Group 1 Pump Device

14 ENG

8 TNDF-03-01-014

67-

High-Pressure Relief Valve Shuttle Valve

8- Low-Pressure Relief Valve 10- Port B (Forward Side Output)

13- Port A (Reverse Side Output) 14- HST Charging Pump

T3-1-21

SECTION3 COMPONENT OPERATION Group 1 Pump Device HST Charging Pump

The HST charging pump is coaxially connected to the shaft of the HST pump. Driving force of the engine is transmitted to the HST pump and the HST charging pump. The HST charging pump is an internal gear pump. Inner rotor (1) and outer rotor (3) rotate together by engaging so that hydraulic oil is drawn to chamber A (4) and delivered from chamber B (2).

12-

T3-1-22

Inner Rotor Chamber B

34-

Outer Rotor Chamber A

TNDF-03-01-012

SECTION3 COMPONENT OPERATION Group 1 Pump Device 4-Gear Pump Unit

Operation: 1. Drive gear (5) is driven via the HST pump, which rotates driven gear (6) as they are meshed together.

The 4-gear pump unit is connected to the HST pump. Driving force of the engine is transmitted to the shaft of the HST pump directly. Then, the shaft rotation of the HST pump is transmitted to the 4-gear pump unit.

2. Pressurized oil (b) drawn from the hydraulic oil tank fills the spaces between the gear teeth of drive gear (5) and driven gear (6), and is supplied to the output port (a) side along the inside of housing (7).

The 4-gear pump unit consists of four gear pumps. Pressurized oil is supplied to each circuit of steering pump (1), main pump (2), pilot pump (3), and transmission charge pump (4) in sequence, seen from the HST pump mounting side. (Refer to SYSTEM / Hydraulic System.) Steering pump (1) supplies pressurized oil to the steering circuit and operates the steering cylinder. It supplies pressurized oil to the main circuit when the steering is not operated. Main pump (2) supplies pressurized oil to the main circuit and operates the lift arm cylinder, bucket cylinder, and other actuators. Pilot pump (3) supplies pressurized oil to the charging circuit and controls the brake and each pilot circuit. In addition, it supplies pressurized oil to the fan circuit and rotates the fan. Transmission charge pump (4) supplies pressurized oil to the transmission circuit and engages the clutch of the transmission.

Output

Suction

56-

Drive Gear Driven Gear

Housing

T3-1-23

T487-03-01-006

SECTION3 COMPONENT OPERATION Group 1 Pump Device

TNDF-03-01-015

Section A-A

Connected to HST Pump

12-

Steering Pump Main Pump

34-

Pilot Pump Transmission Charge Pump

56-

T3-1-24

Drive Gear Driven Gear

TNDF-03-01-016

SECTION 3 COMPONENT OPERATION Group 2 HST Motor Outline The HST (hydrostatic transmission) motor is a bent-axis type variable displacement axial plunger motor. The HST motor consists of the regulator, the shaft, the plunger, the rotor, and the valve plate. (Refer to Rotary Group and Regulator.) The regulator is installed in order to control HST motor 1 (1) and HST motor 2 (2). The motor displacement angle control solenoid valve is installed to it. The flushing valve is installed to HST motor 2 (2). (Refer to HST Motor Layout.) The HST motor is activated by pressurized oil (high pressure or low pressure) from the HST pump.

Two HST motors are equipped for this machine. HST motor 1 (1) and HST motor 2 (2) are installed to transmission (3). Their rotating torque are transmitted to the input shaft of transmission (3). In addition, the power transmitted from HST motor 1 (1) is disconnected by the clutch. When the machine travels at slow speed (speed shift: 1-speed/ 2-speed), HST motor 1 (1) and HST motor 2 (2) are used. When the machine travels at fast speed (speed shift: 3-speed/ 4-speed), HST motor 1 (1) is disconnected by the clutch and only HST motor 2 (2) is used.

HST Motor 1

HST Motor 2

T3-2-1

Transmission

TNDF-03-02-001

SECTION 3 COMPONENT OPERATION Group 2 HST Motor HST Motor Layout

HST Motor 1 (Slow Speed Side): 1

TNDF-03-02-002

HST Motor 2 (Fast Speed Side):

TNDF-03-02-003

10 123-

HST Motor 1 Port T2 Motor 1 Displacement Angle Control Solenoid Valve

4567-

Regulator Port B Port A Port T1

89-

HST Motor 2 Motor 2 Displacement Angle Control Solenoid Valve 10- Flushing Valve

T3-2-2

SECTION 3 COMPONENT OPERATION Group 2 HST Motor

6 7

4 3

1 2

5 d

7 TNDF-03-02-004

ab-

From HST Pump (Port A) From HST Pump (Port B)

Transmission Intput Shaft (Fast Speed)

123-

HST Motor 1 Port T2 Motor 1 Displacement Angle Control Solenoid Valve

4567-

Regulator Port B Port A Port T1

89-

Transmission Intput Shaft (Slow Speed)

HST Motor 2 Motor 2 Displacement Angle Control Solenoid Valve 10- Flushing Valve

T3-2-3

ef-

To Oil Cooler From HST Pump (Port T1)

SECTION 3 COMPONENT OPERATION Group 2 HST Motor Rotary Group Shaft (1) of the rotary group is supported to motor casing (9) by two bearings (8). Center pin (7) is installed in the center hole of rotor (3) and connects shaft (1) to rotor (3). Valve plate (5) is provided in the rotor (3) end and is fit to rotor (3) tightly by the spring (6) force. Nine plungers (2) are installed in rotor (3). Pressurized oil from the HST pump is delivered to either port A (11) or port B (12) and shifts the rotation direction of the HST motor. Operation: 1. Pressurized oil from the HST pump flows to rotor (3) through port A (11) (or port B (12)) in valve plate (5). 2. When plungers (2) in rotor (3) are pushed by pressurized oil, component force (FV) of pushing force (F) rotates shaft (1). 3. As shaft (1) rotates rotor (3), plungers (2) reach port A (11) (or port B (12)) in sequence. 4. When plungers (2) reach the output side port, pressurized oil in rotor (3) is pushed by plungers (2). Therefore, pressurized oil is returned to the HST circuit. 5. Valve plate (5) is connected to regulator (10) through control rod (4). The position of valve plate (5) is changed by the operation of regulator (10) and the motor displacement angle is changed. 6. Therefore, the motor rotation speed varies.

T3-2-4

SECTION 3 COMPONENT OPERATION Group 2 HST Motor

5 10

TNDF-03-02-005

6 5

3 2 1

FR TNDF-03-02-006 F

123-

Shaft Plunger Rotor

456-

Control Rod Valve Plate Spring

789-

T3-2-5

Center Pin Bearing Motor Casing

10- Regulator 11- Port A 12- Port B

SECTION 3 COMPONENT OPERATION Group 2 HST Motor Regulator The regulator controls the motor displacement angle, and increases or decreases the rotation speed of the HST motor. (Refer to SYSTEM / Control System.) The regulator consists of motor displacement angle control solenoid valve (1), servo piston (6), control rod (5), balance spring (4), spring (3), and spool (2).

1 2

Operation: 1. Motor displacement angle control solenoid valve (1) is activate by the signal from the HST controller and operates servo piston (6).

2. Pilot pressurized oil flows to small chamber (7) or large chamber (8), and moves servo piston (6) up and down.

3. Servo piston (6) is connected to valve plate (9) in the motor through control rod (5). The position of valve plate (9) is changed by the operation of servo piston (6).

4. Therefore, the regulator controls the motor displacement angle, and increases or decreases the rotation speed of the HST motor.

TNDF-03-02-007

1234-

T3-2-6

Motor Displacement Angle Control Solenoid Valve Spool Spring Balance Spring

56789-

Control Rod Servo Piston Small Chamber Large Chamber Valve Plate

SECTION 3 COMPONENT OPERATION Group 2 HST Motor Motor Displacement Angle Control Solenoid Valve Motor displacement angle control solenoid valve (1) controls the regulator according to the signal from the HST controller. Motor displacement angle control solenoid valve (1) is a proportional solenoid valve.

T3-2-7

SECTION 3 COMPONENT OPERATION Group 2 HST Motor Motor Displacement Angle Control The motor displacement angle control changes the motor displacement angle in response to the engine speed changes and controls the motor speed. 1

From Large Displacement Angle to Small Displacement Angle (From Slow Speed to Fast Speed)

Operation: 1. Engine speed increases when the accelerator pedal is depressed. 2. Motor displacement angle control solenoid valve (1) shifts spool (2) upward according to the signal (minimum current value) (a) from the HST controller.

3. Pressurized oil (P) from port A (11) (or port B (12)) pushes to open check valve (10) and flows to spool (2) and the small chamber (7) side of servo piston (6).

5 6

4. When pressurized oil (P) in the large chamber (8) side of servo piston (6) flows to drain (13) in the motor case through spool (2), servo piston (6) moves downward and valve plate (9) also moves downward.

5. Therefore, motor 1 displacement angle (q) decreases and the motor rotation speed is increased.

6. Consequently, HST motor 1 rotates at fast speed.

TNDF-03-02-008

f NOTE: In case of the motor displacement angle control, the operation of HST motor 2 is the same.

T3-2-8

SECTION 3 COMPONENT OPERATION Group 2 HST Motor HST Motor 1:

10 5

4 12 13

6 7

TNDF-03-02-009

Signal from HST Controller

P-

Pressurized Oil from HST Pump (Port B)

Motor 1 Displacement Angle

Motor Displacement Angle Control Solenoid Valve Spool Balance Spring

5678-

Control Rod Servo Piston Small Chamber Large Chamber

9101112-

Valve Plate Check Valve Port A Port B

24-

f NOTE: The illustration shows the oil flow of HST motor 1 while driving in forward direction.

T3-2-9

13- Drain in Motor Case

SECTION 3 COMPONENT OPERATION Group 2 HST Motor From Small Displacement Angle to Large Displacement Angle (From Fast Speed to Slow Speed) Operation: 1. Engine speed decreases when the accelerator pedal is released.

2. Motor displacement angle control solenoid valve (1) shifts spool (2) downward according to the signal (maximum current value) (a) from the HST controller.

3. Pressurized oil (P) from port A (11) (or port B (12)) flows to the large chamber (8) side of servo piston (6) through spool (2).

4. As the pressure receiving area in the large chamber (8) side is larger than that in the small chamber (7) side on servo piston (6), servo piston (6) moves upward until it becomes balanced with the spring (4) force.

5 6

5. Therefore, motor 1 displacement angle (q) increases and the motor speed is decreased. 6. Consequently, HST motor 1 rotates at slow speed.

f NOTE: In case of the motor displacement angle control, the operation of HST motor 2 is same.

8 TNDF-03-02-012

T3-2-10

SECTION 3 COMPONENT OPERATION Group 2 HST Motor HST Motor 1:

5 12 13

6 7

q P

TNDF-03-02-010

Signal from HST Controller

P-

Pressurized Oil from HST Pump (Port B)

Motor 1 Displacement Angle

Motor Displacement Angle Control Solenoid Valve Spool Balance Spring

5678-

Control Rod Servo Piston Small Chamber Large Chamber

9101112-

Valve Plate Check Valve Port A Port B

24-

f NOTE: The illustration shows the oil flow of HST motor 1 while driving in forward direction.

T3-2-11

13- Drain in Motor Case

SECTION 3 COMPONENT OPERATION Group 2 HST Motor Flushing Valve Flushing valve (3) is installed to HST motor 2. It receives both high pressure in the HST circuit (motor operating pressure from the HST pump) and low pressure (circuit pressure returned from the HST motor). Then, it releases the hydraulic oil in the low-pressure side to drain circuit (9) and circulates the hydraulic oil in the HST circuit. Operation: 1. Pressurized oil (P2) in the port A (2) side and pressurized oil (P1) in the port B (1) side are routed to spool (7) of flushing valve (3) respectively.

f NOTE: Pressurized oil (P2) in the port A (2) side is low

and pressurized oil (P1) in the port B (1) side is high while driving in forward direction. 2. Pressurized oil (P1) in the port B (1) side is routed to the left side of spool (7). Spool (7) is moved to the right by the pressure at the left side of spool (7) and the spring (4) force. 3. Therefore, pressurized oil (P2) in the port A (2) side flows to drain circuit (9) through spool (7).

f NOTE: Flushing valve (3) is installed to ony HST motor 2.

T3-2-12

SECTION 3 COMPONENT OPERATION Group 2 HST Motor

5 9

TNDF-03-09-010

HST Motor 2:

3 9 8

TNDF-03-02-011

P1- From HST Pump (High Pressure)

P2- To HST Pump (Low Pressure)

12-

34-

Port B Port A

Flushing Valve Spring

57-

f NOTE: The illustration shows the oil flow while driving in forward direction.

T3-2-13

Relief Valve Spool

89-

Spring Drain Circuit

SECTION 3 COMPONENT OPERATION Group 2 HST Motor (Blank)

T3-2-14

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve Outline The multiple control valve controls the pressure, flow rate, and flow direction in the hydraulic circuit. The major parts are the main relief valve, overload relief valve, lowpressure relief valve, and spools. The spools are operated by the pilot oil pressure.

Multiple Control Valve Overview

1 a

TNDF-03-03-003

b a-

Machine Front Side

Machine Left Side

12-

Bucket Spool Lift Arm Spool

Exhaust Filter Regeneration/ Quick Coupler Spool

T3-3-1

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve Multiple Control Valve Hydraulic Diagram

11 12 10 13 9 14 1 15

3 16

TNDF-03-03-002 12345-

Overload Relief Valve (Bucket: Rod Side) Load Check Valve (Bucket Circuit) Make-Up Valve (Lift Arm: Rod Side) Main Relief Valve Low-Pressure Relief Valve

6789-

Load Check Valve (Lift Arm Circuit) Overload Relief Valve (Lift Arm: Bottom Side) Flow Rate Control Valve (Bucket Circuit) Overload Relief Valve (Bucket: Bottom Side)

10- Flow Rate Control Valve (Quick Coupler Circuit) 11- Overload Relief Valve (Quick Coupler Circuit) 12- Orifice (Exhaust Filter Regeneration Circuit) 13- Exhaust Filter Regeneration/ Quick Coupler Spool

T3-3-2

14- Load Check Valve (Exhaust Filter Regeneration/Quick Coupler Circuit) 15- Bucket Spool 16- Lift Arm Spool

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve Layout of Multiple Control Valve

2, 8

7 16 15

13 12

10, 14

TNDF-03-03-001

12345-

Overload Relief Valve (Bucket: Rod Side) Load Check Valve (Bucket Circuit) Make-Up Valve (Lift Arm: Rod Side) Main Relief Valve Low-Pressure Relief Valve

6789-

Load Check Valve (Lift Arm Circuit) Overload Relief Valve (Lift Arm: Bottom Side) Flow Rate Control Valve (Bucket Circuit) Overload Relief Valve (Bucket: Bottom Side)

T3-3-3

14- Load Check Valve (Exhaust Filter Regeneration/Quick Coupler Circuit) 15- Bucket Spool 16- Lift Arm Spool

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve

TNDF-03-03-003

Section A-A 4

TNDB-03-02-006

Section B-B

7 TNDF-03-03-004

16 12345-

Overload Relief Valve (Bucket: Rod Side) Load Check Valve (Bucket Circuit) Make-Up Valve (Lift Arm: Rod Side) Main Relief Valve Low-Pressure Relief Valve

6789-

Load Check Valve (Lift Arm Circuit) Overload Relief Valve (Lift Arm: Bottom Side) Flow Rate Control Valve (Bucket Circuit) Overload Relief Valve (Bucket: Bottom Side)

T3-3-4

14- Load Check Valve (Exhaust Filter Regeneration/Quick Coupler Circuit) 15- Bucket Spool 16- Lift Arm Spool

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve

TNDF-03-03-003

Section C-C 1

Section D-D

TNDF-03-03-005

TNDF-03-03-006

12345-

Overload Relief Valve (Bucket: Rod Side) Load Check Valve (Bucket Circuit) Make-Up Valve (Lift Arm: Rod Side) Main Relief Valve Low-Pressure Relief Valve

6789-

Load Check Valve (Lift Arm Circuit) Overload Relief Valve (Lift Arm: Bottom Side) Flow Rate Control Valve (Bucket Circuit) Overload Relief Valve (Bucket: Bottom Side)

T3-3-5

14- Load Check Valve (Exhaust Filter Regeneration/Quick Coupler Circuit) 15- Bucket Spool 16- Lift Arm Spool

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve Hydraulic Circuit Main Circuit Pressure oil from main pump (19) (or steering pump) flows to hydraulic oil tank (20) through neutral circuit (18) and low-pressure relief valve (5). Parallel circuit (17) is provided in the main circuit and makes the combined operation of each actuator possible. Flow rate control valve (8) is provided in the parallel circuit and gives priority to the lift arm operation. Low-pressure relief valve (5) maintains the specified level pressure in the main circuit and improves the drawing performance of the actuator when cavitation occurs. Main relief valve (4) is provided in the main circuit (between pump and actuator). Main relief valve (4) prevents the pressure in the main circuit from exceeding the set pressure when the spool is operated (or when the control lever is operated). Overload relief valves (1, 7, 9) are provided in the actuator circuit (between multiple control valve and actuator) of lift arm cylinder (21) bottom side and bucket cylinder (22). Overload relief valves (1, 7, 9) prevent the surge pressure caused by external force in the actuator circuit from exceeding the set pressure when the spool is in neutral (with the control lever set in neutral). Make-up valve (3) is provided in the actuator circuit (between multiple control valve and actuator) of lift arm cylinder (21) rod side. Make-up valve (3) draws pressure oil from hydraulic oil tank (20) and prevents cavitation from occurring when the pressure in the actuator circuit decreases. Load check valves (2, 6) are provided in the actuator circuit (between multiple control valve and actuator) of lift arm cylinder (21) and bucket cylinder (22). Load check valves (2, 6) prevent pressure oil in the actuator circuit from flowing reversely.

T3-3-6

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve

18 22

1 15

17 21

3 16

1234-

Overload Relief Valve (Bucket: Rod Side) Load Check Valve (Bucket Circuit) Make-Up Valve (Lift Arm: Rod Side) Main Relief Valve

5678-

Low-Pressure Relief Valve Load Check Valve (Lift Arm Circuit) Overload Relief Valve (Lift Arm: Bottom Side) Flow Rate Control Valve (Bucket: Parallel Circuit)

TNDF-03-03-007

91516171819-

T3-3-7

Overload Relief Valve (Bucket: Bottom Side) Bucket Spool Lift Arm Spool Parallel Circuit Neutral Circuit Main Pump

20212223-

Hydraulic Oil Tank Lift Arm Cylinder Bucket Cylinder Exhaust Filter Regeneration/ Quick Coupler Circuit

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve Main Relief Valve The main relief valve prevents the pressure in the main circuit from exceeding the set pressure when the actuator such as the cylinder is operated. Therefore, oil leak from hose and pipe joints and breakage of the actuator are prevented.  Relief Operation 1. Pressure in port HP (main circuit) is routed to pilot poppet (8) through orifice A (2) in main poppet (1) and orifice B (3) in seat (4). 2. When pressure in port HP reaches the set pressure of spring B (6), pilot poppet (8) is opened, pressure oil from passage A (5) flows to port LP (hydraulic oil tank) through the external circumference of sleeve (11). 3. At this time, a pressure difference is caused between port HP and spring chamber (10) due to orifice A (2). 4. When this pressure difference reaches the set pressure of spring A (9), main poppet (1) is opened and pressure oil from port HP flows to port LP. 5. Consequently, the main circuit pressure decreases. 6. When the main circuit pressure decreases to the specified pressure, main poppet (1) is closed by the force of spring A (9).

T3-3-8

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve During Normal Operation: 1

TNED-03-02-013

During Relief Operation: 3

HP- Main Circuit

LP- Hydraulic Oil Tank

123-

456-

Main Poppet Orifice A Orifice B

Seat Passage A Spring B

8- Pilot Poppet 9- Spring A 10- Spring Chamber

T3-3-9

TNED-03-02-014

11- Sleeve

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve Overload Relief Valve The overload relief valve is used for the lift arm raise and bucket tilt circuits and for the bucket dump circuit. The overload relief valve prevents each actuator circuit pressure from rising excessively when the actuators are moved by external force. In addition, when the actuator circuit pressure decreases, the overload relief valve draws pressure oil from the hydraulic oil tank and prevents the occurrence of cavitation (make-up function). Overload Relief Valve for Bucket Dump Circuit  Relief Operation 1. Pressure in port HP (actuator circuit) is routed to pilot poppet (8) through orifice (1) of piston (3). 2. When pressure in port HP reaches the set pressure of spring B (6), pilot poppet (8) is opened, pressure oil from passage A (5) flows to port LP (hydraulic oil tank) through the external circumference of sleeve (10). 3. At this time, a pressure difference occurs between port HP and spring chamber (9) due to orifice (1). 4. When this pressure difference reaches the set pressure of spring A (4), piston (3) and main poppet (2) are opened and pressure oil from port HP flows to port LP. 5. Consequently, the actuator circuit pressure decreases. 6. When the actuator circuit pressure decreases to the specified pressure, piston (3) and main poppet (2) are closed by the force of spring A (4).

T3-3-10

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve During Normal Operation: 2

T4GB-03-02-030

During Relief Operation: 2

HP- Actuator Circuit

LP- Hydraulic Oil Tank

123-

456-

Orifice Main Poppet Piston

Spring A Passage A Spring B

T4GB-03-02-031

789-

T3-3-11

Spring C Pilot Poppet Spring Chamber

10- Sleeve

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve  Make-Up Operation 1. When pressure in port HP (actuator circuit) decreases lower than pressure in port LP (hydraulic oil tank), sleeve (10) is moved to the right. 2. Hydraulic oil in port LP flows to port HP and cavitation is prevented. 3. When pressure in port HP increases to the specified pressure, sleeve (10) is closed by the force of spring C (7).

T3-3-12

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve During Make-Up Operation: 10

7 T4GB-03-02-032

HP- Actuator Circuit

LP- Hydraulic Oil Tank

10- Sleeve

Spring C

T3-3-13

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve Overload Relief Valve for Lift Arm Raise and Bucket Roll Back Circuits  Relief Operation 1. Pressure in port HP (actuator circuit) is routed to shaft (2) through seat (1). 2. When pressure in port HP reaches the set pressure of spring A (4), shaft (2) is moved and pressure oil flows to port LP (hydraulic oil tank). 3. Consequently, the actuator circuit pressure decreases. 4. When the actuator circuit pressure decreases to the specified level, shaft (2) is moved by the force of spring A (4) and the oil passage is closed.  Make-Up Operation 1. When pressure in port HP (actuator circuit) decreases lower than pressure in port LP (hydraulic oil tank), seat (1) is moved to the right. 2. Hydraulic oil in port LP flows to port HP and cavitation is prevented. 3. When pressure in port HP increases to the specified pressure, seat (1) is closed by the force of spring B (3).

T3-3-14

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve Normal Operation: 1

T4GB-03-02-027

T4GB-03-02-028

T4GB-03-02-029

During Relief Operation: 1

During Make-Up Operation: 1

HP- Actuator Circuit:

LP- Hydraulic Oil Tank

Seat

Shaft

T3-3-15

Spring B

Spring A

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve Make-Up Valve The make-up valve draws pressure oil from the hydraulic oil tank and prevents cavitation from occurring when the pressure in the lift arm lower circuit decreases. NOTE: Each overload relief valve in other circuits is equipped with make-up function. Therefore, cavitation is prevented from occurring.

 Make-Up Operation 1. Pressure oil in port HP (actuator circuit) is routed to spring chamber (4) through passage (2) of poppet (1). The pressure in port HP becomes equal to the pressure in spring chamber (4). 2. When pressure in port HP (actuator circuit) decreases lower than pressure in port LP (hydraulic oil tank), poppet (1) is moved to the right. 3. Consequently, poppet (1) is opened, hydraulic oil in port LP flows to port HP, and cavitation is prevented. 4. When pressure (port HP + spring (3) force) in port HP increases higher than pressure in port LP, poppet (1) is moved to the left. 5. Therefore, poppet (1) is closed and the oil passage between port HP and port LP (hydraulic oil tank) is closed.

T3-3-16

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve During Normal Operation:

LP TNDF-03-03-009

During Make-Up Operation:

LP TNDF-03-03-010

Poppet

Passage

T3-3-17

Spring

Spring Chamber

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve Flow Rate Control Valve The flow rate control valve consists of a check valve (6) and orifice (7). The flow rate control valve is provided in parallel circuit (4) and gives priority to the lift arm operation.

 During Combined Operation of Lift Arm Raise and Bucket Tilt:

1. One pressure oil from main pump (12) flows lift arm spool (3) through load check valve (2) and moves lift arm cylinder (9).

2. Other pressure oil flows to parallel circuit (4), flows to bucket spool (8) through the flow rate control valve, and moves bucket cylinder (9).

3. Pressure oil which flows to the bucket tilt circuit pushes to open check valve (6), flows to orifice (7), and is regulated.

13 T4GB-03-02-020

4. Therefore, more pressure oil is supplied to the higher load lift arm raise circuit. 5. Consequently, operation of lift arm raise and bucket tilt are performed at the same time.

246-

T3-3-18

Load Check Valve Parallel Circuit Check Valve (Flow Rate Control Valve)

Orifice (Flow Rate Control Valve) 8- Bucket Spool 13- Neutral Circuit

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve

8 6

Pia2

Pia1

Pia1- Lift Arm Raise

Pia2- Bucket Tilt

12-

46-

Multiple Control Valve Load Check Valve (Lift Arm Circuit) Lift Arm Spool

Parallel Circuit Check Valve (Flow Rate Control Valve)

TNDF-03-03-011

789-

T3-3-19

Orifice (Flow Rate Control Valve) Bucket Spool Bucket Cylinder

10111213-

Lift Arm Cylinder Hydraulic Oil Tank Main Pump Neutral Circuit

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve Pilot Operation Control Circuit Pressure oil from the pilot valve acts on the spool in the multiple control valve in order to move the spool.  During bucket dump (Pib2) operation, pressure oil moves bucket spool (5).  During lift arm lower (Pib1) operation, pressure oil moves lift arm spool (6). Lift arm spool (6) has two stage functions. First stage function is lift arm lower (a) and second stage function is lift arm float (b). (Refer to Lift Arm Float Control.) Slow Return Valve 13

Slow return valve (7) is provided in the inlet port of the pilot circuit at the both ends of lift arm spool (6). 1. When the lift arm control lever is set to the neutral position, pilot pressure oil (Pia1 or Pib1) which has been supplied to lift arm spool (6) flows to hydraulic oil tank (9) through orifice (12) in slow return valve (7) and lift arm pilot valve (2).

2. Therefore, pilot pressure slowly decreases. 3. Consequently, as lift arm spool (6) is returned to the neutral position slowly, the vehicle shock developed when operate the lift arm is reduced.

T4GB-03-02-014 a-

Multiple Control Valve Side

7- Slow Return Valve 12- Orifice

T3-3-20

Lift Arm Pilot Valve Side

13- Pilot Valve Side

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve

Pib2

Pia2 Pia1

Pib1

Pia2

Pib2

6 a

b Pib1

Pia1

Pia1- Lift Arm Raise

Pib1- Lift Arm Lower

Lift Arm Lower

Lift Arm Float

123-

Bucket Pilot Valve Lift Arm Pilot Valve Pilot Pump

456-

Multiple Control Valve Bucket Spool Lift Arm Spool

TNDF-03-03-008

Pia2- Bucket Tilt

Pib2- Bucket Dump

789-

10- Lift Arm Cylinder 11- Bucket Cylinder

T3-3-21

Slow Return Valve Main Pump Hydraulic Oil Tank

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve Lift Arm Float Control Operation: 1. If lift arm lower (Pib1) is fully stroked, the lift arm control lever is secured in the stroke end due to electromagnetic detent of the pilot valve. 2. Pressure oil (Pib1) from the pilot valve moves lift arm spool (2) to the left. 3. Therefore, pressure oil in the rod and bottom sides of lift arm cylinder (1) flow to hydraulic oil tank (4). 4. Consequently, the lift arm can move freely depending on the external force. (Refer to Control System.)

T3-3-22

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve

Pib1

T4FC-03-02-012

Pib1

T4FC-03-02-010

4 Pib1- Lift Arm Lower 1-

Lift Arm Cylinder

Lift Arm Spool

T3-3-23

Main Pump

Hydraulic Oil Tank

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve External Pilot Pressure Circuit In case of exhaust filter regeneration (PibX), exhaust filter regeneration spool (3) in the exhaust filter regeneration circuit is moved by pressure oil. (Refer to Control System.) Exhaust Filter Regeneration Circuit Operation: 1. Pressure oil (PibX) from the exhaust filter regeneration control solenoid valve unit moves exhaust filter regeneration/quick coupler spool (3) toward the arrow. 2. When the control levers of pilot valves (bucket and lift arm) are in the neutral position, pressure oil from main pump (7) flows to exhaust filter regeneration/ quick coupler spool (3) through neutral circuit (4) and load check valve (5) and flows to orifice (2). 3. Pressure oil from main pump (7) is reduced by orifice (2) and the pressure in neutral circuit (4) increases. 4. Consequently, the load applied to main pump (7) increases and regeneration of the exhaust filter is possible. (Refer to System/Hydraulic System.)

T3-3-24

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve

3 6 PibX

5 4

TNDF-03-03-012

7 5

TNDF-03-03-013

PibX- Exhaust Filter Regeneration 123-

Multiple Control Valve Orifice Exhaust Filter Regeneration/ Quick Coupler Spool

45-

Neutral Circuit Load Check Valve (Exhaust Filter Regeneration/Quick Coupler)

678-

T3-3-25

Exhaust Filter Regeneration Circuit Main Pump Hydraulic Oil Tank

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve Quick Coupler Circuit (Option) Operation: 1. Pressure oil (PiaX) from the hydraulic coupler solenoid valve moves exhaust filter regeneration/ quick coupler spool (3) toward the arrow. 2. Pressure oil from main pump (7) flows to quick coupler circuit (10) through exhaust filter regeneration/quick coupler spool (3). 3. Therefore, coupler cylinder (11) is operated. (Refer to Hydraulic System/SYSTEM.)

fNOTE: Overload relief valve (9) prevents the pressure

developed at the stroke end from exceeding the set pressure. The set pressure of overload relief valve (9) is lower than that of the overload relief valve in the main circuit.

T3-3-26

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve

3 8

PiaX

TNDF-03-03-014

PiaX- Hydraulic Coupler 13-

Multiple Control Valve Exhaust Filter Regeneration/ Hydraulic Coupler Spool

78-

Main Pump Hydraulic Oil Tank

Overload Relief Valve (Quick Coupler Circuit) 10- Quick Coupler Circuit (OPT)

fNOTE: The illustration shows the oil flow during hydraulic coupler lock operation.

T3-3-27

11- Coupler Cylinder

SECTION 3 COMPONENT OPERATION Group 3 Multiple Control Valve (Blank)

T3-3-28

SECTION 3 COMPONENT OPERATION Group 4 Fan Motor and Fan Valve Fan Motor The fan motor is a swash plate type axial plunger motor. The fan motor consists of rotor (1), shaft (2), swash plate (3), shoe (4), retainer (5), and plunger (6). Shaft (2) is connected to rotor (1) by a spline joint, and plunger (6) is inserted into rotor (1).

When pressurized oil is supplied from the pilot pump, plunger (6) is pushed. As swash plate (3) is inclined, shoe (4) on the end of plunger (6) slides along swash plate (3) and rotor (1) rotates. The end of shaft (2) is connected to the fan by key (7). Therefore, the rotation of shaft (2) is transmitted to the fan.

6 P1- Port P1

P2- Port P2

12-

34-

Rotor Shaft

Swash Plate Shoe

56-

T3-4-1

Retainer Plunger

key

TNED-03-03-009

SECTION 3 COMPONENT OPERATION Group 4 Fan Motor and Fan Valve Fan Valve The fan valve consists of fan speed control solenoid valve (1) and fan control valve (2). Fan speed control solenoid valve (1) is shifted when pressure of pressurized oil from the pilot pump reaches the relief set pressure. Then, it relieves pressurized oil from the pilot pump. Fan control valve (2) is also shifted when fan speed control solenoid valve (1) is shifted. Then, it relieves pressurized oil from the pilot pump.

As pressurized oil from the pilot pump is relieved by fan speed control solenoid valve (1) and fan control valve (2), pressurized oil flowing to the fan motor decreases and the flow rate is controlled to become best. (Refer to SYSTEM / Control System.)

TNED-02-04-036

T3-4-2

SECTION 3 COMPONENT OPERATION Group 4 Fan Motor and Fan Valve

Dr AB-

Port A Port B

PT-

Pump Port Tank Port

Fan Speed Control Solenoid Valve

Fan Control Valve

P Dr- Drain Port

T3-4-3

TDAB-03-07-007

SECTION 3 COMPONENT OPERATION Group 4 Fan Motor and Fan Valve Operation (Fan Speed Control) 1. Pressurized oil from pilot pump (9) is divided in fan valve (3). One flows to fan motor (4) and the other flows to the spring (6) chamber through poppet (5) and orifice (10) in the fan control valve. In addition, the other flows to spool (7) in the fan speed control solenoid valve through passage B (8) in fan valve (3).

2. When the output pressure of pilot pump (9) reaches the relief set pressure, spool (7) moves to the right (down on the circuit diagram). 3. Therefore, pressurized oil from passage B (8) flows to hydraulic oil tank (1) through spool (7).

4. At this time, a pressure difference occurs between passage A (2) and passage B (8) due to orifice (10). Then, poppet (5) moves to the left (down on the circuit diagram).

6 8

5. Therefore, pressurized oil routed to poppet (5) flows to hydraulic oil tank (1). 6. Consequently, the flow rate of pressurized oil flowing to fan motor (4) is controlled to become best.

TDAB-03-07-004

123456-

T3-4-4

Hydraulic Oil Tank Circuit A Fan Valve Fan Motor Poppet (Fan Control Valve) Spring

Spool (Fan Speed Control Solenoid Valve) 8- Circuit B 9- Pilot Pump 10- Orifice

SECTION 3 COMPONENT OPERATION Group 4 Fan Motor and Fan Valve

7 b

9 6

TDAB-03-07-003

Pressurized oil to Fan Motor

Signal from MC (Main Controller)

123-

Hydraulic Oil Tank Circuit A Fan Valve

456-

Fan Motor Poppet (Fan Control Valve) Spring

78-

T3-4-5

Spool (Fan Speed Control Solenoid Valve) Circuit B

9- Pilot Pump 10- Orifice

SECTION 3 COMPONENT OPERATION Group 4 Fan Motor and Fan Valve Fan Valve (with Fan Reverse Rotation) The fan valve (with fan reverse rotation) consists of fan speed control solenoid valve (1), fan reverse rotation control solenoid valve (2), fan control valve (3), and fan reverse rotation spool (4). Fan speed control solenoid valve (1) is shifted by the signals from MC and controls the operation of fan control valve (3). Fan control valve (3) is shifted according to the operation of fan speed control solenoid valve (1) and flows pressurized oil from the pilot pump to the hydraulic oil tank. Therefore, pressurized oil flowing to the fan motor decreases and the fan can rotate at the best speed. (Refer to SYSTEM / Control System.)

In addition, when the fan reverse rotation switch is turned ON, fan reverse rotation control solenoid valve (2) is shifted by the signals from MC. Therefore, fan reverse rotation spool (4) is shifted and the fan rotates in reverse.

T3-4-6

SECTION 3 COMPONENT OPERATION Group 4 Fan Motor and Fan Valve

4 3

TNED-03-03-001

AB-

Port A Port B

PS-

Pump Port Sensor Port

T- Tank Port Dr- Drain Port

Fan Speed Control Solenoid Valve

Fan Reverse Rotation Control Solenoid Valve

34-

T3-4-7

Fan Control Valve Fan Reverse Rotation Spool

SECTION 3 COMPONENT OPERATION Group 4 Fan Motor and Fan Valve Operation  Normal Rotation 1. Pressurized oil from port P is divided into three directions. One flows to fan reverse rotation spool (2) and the other flows to poppet (3) in fan control valve (5). The other flows to fan speed control solenoid valve (7), fan reverse rotation control solenoid valve (6), and the spring (4) chamber in fan control valve (5).

2. As fan reverse rotation control solenoid valve (6) is not shifted during normal rotation, fan reverse rotation spool (2) is pushed by the spring (1) force toward the arrow.

3. Pressurized oil from port P flows to the fan motor through the periphery of fan reverse rotation spool (2) and port A. P

4. Therefore, the fan rotates in normal direction.

TNED-02-04-035

PTDrA-

From Pilot Pump To Hydraulic Oil Tank To Hydraulic Oil Tank To Fan Motor (Normal Rotation Side)

B-

To Fan Motor (Reverse Rotation Side)

1245-

Spring Fan Reverse Rotation Spool Spring Fan Control Valve

Fan Reverse Rotation Control Solenoid Valve Fan Speed Control Solenoid Valve

T3-4-8

SECTION 3 COMPONENT OPERATION Group 4 Fan Motor and Fan Valve

4 P

2 3

TNED-03-03-005

PT-

From Pilot Pump To Hydraulic Oil Tank

Dr- To Hydraulic Oil Tank

A-

To Fan Motor (Normal Rotation Side)

B-

To Fan Motor (Reverse Rotation Side)

123-

Spring Fan Reverse Rotation Spool Poppet

45-

Fan Reverse Rotation Control Solenoid Valve

Fan Speed Control Solenoid Valve

Spring Fan Control Valve

T3-4-9

SECTION 3 COMPONENT OPERATION Group 4 Fan Motor and Fan Valve  Reverse Rotation 1. When the fan reverse rotation switch is turned ON, fan reverse rotation control solenoid valve (6) is shifted by the signals from Main Controller (MC). (Refer to SYSTEM / Control System.) 2. Pressurized oil from port P is routed to the end of fan reverse rotation spool (2) through spool (8) of fan reverse rotation control solenoid valve (6). 3. Therefore, fan reverse rotation spool (2) moves toward the arrow.

4. Pressurized oil from port P flows to the fan motor through the periphery of fan reverse rotation spool (2) and port B.

5. Therefore, the fan rotates in reverse direction.

TNED-02-04-052

P- From Pilot Pump T- To Hydraulic Oil Tank Dr- To Hydraulic Oil Tank

268-

T3-4-10

Fan Reverse Rotation Spool Fan Reverse Rotation Control Solenoid Valve Spool

AB-

To Fan Motor (Normal Rotation Side) To Fan Motor (Reverse Rotation Side)

SECTION 3 COMPONENT OPERATION Group 4 Fan Motor and Fan Valve

TNED-03-03-006

PT-

From Pilot Pump To Hydraulic Oil Tank

Dr- To Hydraulic Oil Tank

A-

To Fan Motor (Normal Rotation Side)

Fan Reverse Rotation Spool

Spool

Fan Reverse Rotation Control Solenoid Valve

T3-4-11

B-

To Fan Motor (Reverse Rotation Side)

SECTION 3 COMPONENT OPERATION Group 4 Fan Motor and Fan Valve  Fan Speed Control 1. MC activates fan speed control solenoid valve (7) according to coolant temperature, and HST oil temperature. (Refer to SYSTEM / Control System.) 2. Therefore, the spring (4) chamber is connected to port Dr (hydraulic oil tank). 3. Pressurized oil in the spring (4) chamber flows to port Dr (hydraulic oil tank) through orifice (11), passage (9), and the spool (10) of fan speed control solenoid valve (7).

4. Therefore, the pressure in the spring (4) chamber decreases.

5. When the pressure in the spring (4) chamber is lower than the pressure at port P, poppet (3) in fan control valve (5) moves toward the arrow and pressurized oil from port P flows to port T (hydraulic oil tank).

6. Therefore, pressurized oil flowing to the fan motor decreases and the fan speed becomes slow.

7. Therefore, the fan can rotate at the best speed. 8. In addition, pressurized oil in the spring (4) chamber flows to port Dr (hydraulic oil tank) through orifice (11) in small steps. 9. Therefore, the fan speed is prevented from changing suddenly.

TNED-02-04-036

P- From Pilot Pump T- To Hydraulic Oil Tank Dr- To Hydraulic Oil Tank

A-

457-

10- Spool 11- Orifice

T3-4-12

Spring Fan Control Valve Fan Speed Control Solenoid Valve Passage

B-

To Fan Motor (Normal Rotation Side) To Fan Motor (Reverse Rotation Side)

SECTION 3 COMPONENT OPERATION Group 4 Fan Motor and Fan Valve

4 P

3 9 Dr

P- From Pilot Pump T- To Hydraulic Oil Tank Dr- To Hydraulic Oil Tank

A-

345-

Poppet Spring Fan Control Valve

TNED-03-03-007

To Fan Motor (Normal Rotation Side)

Ba-

Fan Speed Control Solenoid Valve 9- Passage 10- Spool

To Fan Motor (Reverse Rotation Side) Signal from MC

11- Orifice

T3-4-13

SECTION 3 COMPONENT OPERATION Group 4 Fan Motor and Fan Valve Make-Up Operation 1. When pressure at port A or port B is lower than pressure at port T (hydraulic oil tank), check valve (12) moves up. 2. Hydraulic oil in port T flows to port A or port B and cavitation is prevented. 3. When pressure at the port A or port B side rises to the specified pressure, check valve (12) is closed by the spring (13) force.

TNED-03-03-008

T-

To Hydraulic Oil Tank

12- Check Valve

A-

To Fan Motor (Normal Rotation Side)

B-

13- Spring

T3-4-14

To Fan Motor (Reverse Rotation Side)

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Outline The steering valve (OrbitrolTM) is located between the priority valve and the steering cylinder. The steering valve supplies pressurized oil from the steering pump to the steering cylinder through the priority valve in response to the movement of the steering wheel. (Refer to SYSTEM / Hydraulic System / Steering Circuit.)

T4FC-03-04-001

Steering Wheel

12-

Port L (for Steering (Left)) Port R (for Steering (Right))

34-

Port P (from Priority Valve) Port T (to Hydraulic Oil Tank)

T3-5-1

Port LS

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Structure

The steering valve consists of rotor (gerotor) (8), drive (7), sleeve (3), spool (4), pin (5), housing (1), centering springs (2), and others. When the steering wheel is rotated, spool (4) rotates and an oil passage is generated between spool (4) and sleeve (3). Pressurized oil from the steering pump is controlled by spool (4) and sleeve (3), and flows to the steering cylinder. Centering springs (2) are arranged in both spool (4) and sleeve (3), and return sleeve (3) to the neutral position when the steering handle operation is stopped.

T4FC-03-04-007

2 5 4

2 3 1

12 5

10 9

1234-

Housing Centering Spring Sleeve Spool

5678-

Pin Plate Drive Rotor (Gerotor)

T4FC-03-04-002 9101112-

T3-5-2

Spacer Cap Check Valve Hole

13- Load Check Valve

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Operation Sleeve (3), spool (4), and drive (7) are mutually connected by pin (5). When the steering wheel (spool (4)) is rotated, a relative angular difference arises between sleeve (3) and spool (4) as hole (12) of spool (4) is a lengthened one. The movement of the steering wheel is transmitted only to spool (4), and port P (from the main pump) is connected to port R (to the steering cylinder (right)) or port L (to the steering cylinder (left)) through sleeve (3) and spool (4).

8 7

3 4 2

TNDF-03-05-001

T4FC-03-04-003

Steering Wheel

T3-5-3

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Steering (Left) 1. When the steering wheel is rotated left, spool (4) rotates via shaft (16), and pressurized oil from main pump (15) flows in the order of port P - sleeve (3) spool (4) - sleeve (3) - housing (1) - rotor (gerotor) (8).

4. When pressurized oil from main pump (15) enters rotor (8), rotor (8) rotates left. The rotation of rotor (8) is transmitted to sleeve (3) through drive (7) and sleeve (3) rotates left similarly. 5. When sleeve (3) rotates the same amount of turns as spool (4), the passages of sleeve (3) and spool (4) are closed and operation of steering cylinder (13) is stopped.

2. Pressurized oil from rotor (8) flows in the order of housing (1) - sleeve (3) - spool (4) - sleeve (3) - port L - steering cylinder (13). Then, it moves steering cylinder (13) and directs the vehicle body left.

6. Therefore, rotor (8) rotates in response to the rotation of the steering wheel and steering cylinder (13) is operated in response to the amount of turns of the steering wheel.

3. Returning oil from steering cylinder (13) enters port R, flows in the order of housing (1) - sleeve (3) - spool (4) - sleeve (3) - port T, and returns to the hydraulic oil tank.

15 1 8 7

16 123-

Housing Centering Spring Sleeve

478-

Spool Drive Rotor (Gerotor)

TNDF-03-04-004

3 13- Steering Cylinder 14- Steering Valve 15- Main Pump

T3-5-4

16- Shaft

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Steering (Right) 1. When the steering wheel is rotated right, pressurized oil from the main pump flows in the order of port P - port R - steering cylinder, moves the steering cylinder, and directs the vehicle body right.

2. Returning oil from the steering cylinder flows in the order of port L - port T and returns to the hydraulic oil tank.

TNDB-03-04-010

Neutral

1. When the steering wheel is not rotated, pressurized oil from the main pump is blocked by spool (4) and does not flow to the steering cylinder. 2. Therefore, the steering cylinder is not operated.

T3-5-5

TNDB-03-04-011

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Overload Relief Valve R

Overload relief valve (4) consists of poppet (2) and spring (3), and is located in steering valve (1). When spool (7) is in the neutral position, overload relief valve (4) prevents pressure in the circuit (between steering valve and steering cylinder) due to surge pressure developed by external force from exceeding the set pressure.

Relief Operation 1. When the pressure in the circuit (between steering valve and steering cylinder) exceeds the spring (3) force, poppet (2) pushes spring (3) and moves right. 2. Therefore, the oil passage is connected to port T. Pressurized oil in the circuit flows to the hydraulic oil tank through port T.

7 T

13-

T3-5-6

Steering Valve Spring

47-

TNDF-03-05-003

Overload Relief Valve Spool

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve

Section A-A

T4FC-03-04-011

A T4FC-03-04-009

12-

Steering Valve Poppet

34-

Spring Overload Relief Valve

T3-5-7

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Make-Up Valve

Make-up valve (6) is located in steering valve (1). Make-up valve (6) draws pressurized oil from the hydraulic oil tank and prevents cavitation from occurring when the pressure in the circuit (between steering valve and steering cylinder) decreases below the specified value.

Make-Up Operation 1. When the pressure in the circuit (between steering valve and steering cylinder) decreases below the pressure in hydraulic oil tank (10), the ball of makeup valve (6) moves right. 2. Therefore, the oil passage is connected to port T. Pressurized oil from the hydraulic oil tank is drawn through port T and flows to the circuit.

7 T

14-

T3-5-8

Steering Valve Overload Relief Valve

67-

TNDF-03-05-003

Make-Up Valve Steering Spool

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve

B T4FC-03-04-009

Section B-B

T4FC-03-04-013

View C

Section D-D T

D T4FC-03-04-012 D

5T4FC-03-04-010

T3-5-9

Ball

Make-Up Valve

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve (Blank)

T3-5-10

SECTION 3 COMPONENT OPERATION Group 6 Priority Valve Outline Priority valve (1) supplies pressurized oil from the steering pump to the steering valve and the multiple control valve in response to the movement of the steering valve. (Refer to SYSTEM / Hydraulic System.) Steering relief valve (2) prevents the pressure in the circuit (between priority valve and steering valve) from increasing over the set pressure while operating the steering wheel.

1 CF

P- From Steering Pump CF- To Steering Valve 12-

EF- To Multiple Control Valve LS- To Steering Valve

T-

Priority Valve Steering Relief Valve

T3-6-1

To Hydraulic Oil Tank

TNDF-03-06-001

SECTION 3 COMPONENT OPERATION Group 6 Priority Valve Structure Priority valve (1) consists of steering relief valve (2), spool (5), spring (3), and orifices (4, 6, 7). Spool (5) is pushed left by spring (3) with the engine stopped. Port P is connected to the steering pump and port CF is connected to the steering valve. Port EF is connected to the multiple control valve. NOTE: The illustration on the right shows the spool (5) position with the engine stopped.

T3-6-2

SECTION 3 COMPONENT OPERATION Group 6 Priority Valve

1 CF

P- From Steering Pump CF- To Steering Valve

EF- To Multiple Control Valve LS- To Steering Valve

T-

To Hydraulic Oil Tank

12-

34-

56-

Spool Orifice A

Priority Valve Steering Relief Valve

Spring Orifice B

T3-6-3

TNDF-03-06-001

Orifice C

SECTION 3 COMPONENT OPERATION Group 6 Priority Valve Operation When steering is in neutral 1. Pressurized oil from steering pump (9) is supplied to port P and is divided into three directions, port CF, port EF, and port LS through the inner passage in spool (4). 2. When not operating steering wheel (15), pressurized oil from port CF is blocked by steering spool (14) and pressure at port CF increases. 3. As pressure at port CF increases, pressurized oil from steering pump (9) flows to chamber A (2) and chamber B (5) through orifice A (3) and orifice B (6) respectively. 4. As pressurized oil in chamber B (5) flows to hydraulic oil tank (18) through orifice C (20), port LS, and the neutral circuit in steering spool (14), pressure in chamber B (5) is lower than pressure in chamber A (2) due to orifice B (6). 5. When the pressure difference exceeds the spring (7) force, the spool moves right. 6. Therefore, more pressurized oil from steering pump (9) is supplied to multiple control valve (a) through port EF.

T3-6-4

SECTION 3 COMPONENT OPERATION Group 6 Priority Valve 10

14 15 19 16

18 P1

a CF

T P

P- Pump Port CF- Port CF P1- Port P1

EF- Port EF a- To Multiple Control Valve LS- Port LS

TLR-

Tank Port Port L Port R

123456-

789101112-

131415161718-

Rotor (Gerotor) Steering Spool Steering Wheel Orifice (Variable) Sleeve Hydraulic Oil Tank

Priority Valve Chamber A Orifice A Spool Chamber B Orifice B

Spring Steering Relief Valve Steering Pump Steering Cylinder (Left) Steering Cylinder (Right) Steering Valve

T3-6-5

TNDF-03-06-002

19- Orifice (Variable) 20- Orifice C

SECTION 3 COMPONENT OPERATION Group 6 Priority Valve When steering is operated

fNOTE: Orifices (16, 19) of steering valve (12) are

variable orifices and the opening area of them become large in proportion to the amount of stroke of steering wheel (15). Then, pressurized oil is supplied to steering cylinders (10, 11) without flowing through rotor (gerotor) (13). 1. When steering wheel (15) is rotated, spool (14) of steering valve (12) moves and orifices (16, 19) are opened. 2. Pressurized oil in the circuit between chamber A (2) in priority valve (1) and orifice (16) in steering valve (12) flows to rotor (13). 3. When pressurized oil flows to rotor (13), the pressure in the circuit between chamber A (2) in priority valve (1) and orifice (16) in steering valve (12) through port CF decreases. Then, spool (4) of priority valve (1) moves left. 4. Spool (4) of priority valve (1) is kept at the position where pressurized oil equivalent to the open amount of orifices (16, 19) flows to steering valve (12). 5. At this time, pressurized oil from steering pump (9) flows to steering valve (12) through spool (4) of priority valve (1) and port CF, and excessive pressurized oil flows to multiple control valve (a) through port EF. 6. Pressurized oil from steering pump (9) flows to rotor (13) through spool (14) and sleeve (17) of steering valve (12). 7. Rotor (13) delivers pressurized oil as a hydraulic motor while turning. This pressurized oil flows to steering cylinders (10, 11) at right and left through spool (4) and port R (or port L) so that the vehicle turns.

fNOTE: The illustration on the right shows the oil flow when steering wheel (15) is rotated right.

T3-6-6

SECTION 3 COMPONENT OPERATION Group 6 Priority Valve 10

13 14 15

19 T

16 P1

6 a

T P

P- Pump Port CF- Port CF P1- Port P1

EF- Port EF a- To Multiple Control Valve LS- Port LS

TLR-

Tank Port Port L Port R

123456-

789101112-

131415161718-

Rotor (Gerotor) Steering Spool Steering Wheel Orifice (Variable) Sleeve Hydraulic Oil Tank

Priority Valve Chamber A Orifice A Spool Chamber B Orifice B

Spring Steering Relief Valve Steering Pump Steering Cylinder (Left) Steering Cylinder (Right) Steering Valve

T3-6-7

TNDF-03-06-003

19- Orifice (Variable) 20- Orifice C

SECTION 3 COMPONENT OPERATION Group 6 Priority Valve When steering cylinder is at stroke end 1. Pressurized oil from port P1 of steering valve (12) is divided in spool (14), flows to rotor (13) and port LS of priority valve (1) through orifices (16, 19), and is routed to chamber B (5) through orifice C (20). 2. When steering cylinders (10, 11) at right and left reach the stroke end, the pressure at port P1 increases and the pressure in chamber B (5) in priority valve (1) also increases due to port LS. 3. When the pressure in chamber B (5) increases over the specified value, steering relief valve (8) in priority valve (1) is activated. 4. Therefore, pressurized oil routed to chamber B (5) flows to hydraulic oil tank (18) through steering relief valve (8). 5. Therefore, the pressure difference is generated between chamber A (2) and chamber B (5) due to orifice B (6). 6. When pressure in chamber A (2) increases over pressure in chamber B (5) and the spring (7) force, spool (4) of priority valve (1) moves right. 7. Pressurized oil from steering pump (9) flows to multiple control valve (a) through spool (4) of priority valve (1) and port EF. 8. Therefore, more pressurized oil is supplied to the multiple control valve when steering cylinders (10, 11) at right and left are at the stroke end. 9. In addition, pressure routed to steering cylinders (10, 11) at right and left through port R (or port L) is equal to the set pressure of steering relief valve (8).

T3-6-8

SECTION 3 COMPONENT OPERATION Group 6 Priority Valve 10

13 14 15

19 16

18 P1

6 a

T P

7 3

P- Pump Port CF- Port CF P1- Port P1

EF- Port EF a- To Multiple Control Valve LS- Port LS

TLR-

Tank Port Port L Port R

123456-

789101112-

131415161718-

Rotor (Gerotor) Steering Spool Steering Wheel Orifice (Variable) Sleeve Hydraulic Oil Tank

Priority Valve Chamber A Orifice A Spool Chamber B Orifice B

Spring Steering Relief Valve Steering Pump Steering Cylinder (Left) Steering Cylinder (Right) Steering Valve

T3-6-9

TNDF-03-06-004

19- Orifice (Variable) 20- Orifice C

SECTION 3 COMPONENT OPERATION Group 6 Priority Valve (Blank)

T3-6-10

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve Outline (Joystick Type Pilot Valve for Front Attachment) The pilot valve controls pilot pressurized oil in order to move the spool in the multiple control valve. The pilot valve outputs pressure according to the control lever stroke by PPC (Pressure Proportional Control Valve) function and moves the spool in the multiple control valve. Port No. 1 2 3 4

Bucket Dump Bucket Roll Back Lift Arm Raise Lift Arm Lower

Hydraulic Symbol

P T 1

4 T4GB-03-05-001

PT-

T3-7-1

Port P (Pressurized Oil from Pilot Pump) Port T (To Hydraulic Oil Tank)

TNDF-03-07-001

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve Operation The spool (7) head comes in contact with the upper surface of spring guide (4). Spring guide (4) is kept raised by return spring (6).

fNOTE: Total lever stroke is determined by stroke dimension (E) of pusher (2).

2 4 7

6 8 3 TNED-03-06-003

12-

Cam Pusher

34-

Casing Spring Guide

56-

T3-7-2

Balance Spring Return Spring

78-

Spool Hole

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve (Blank)

T3-7-3

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve Neutral (Output Curve: A to B) 1. When in neutral, spool (7) completely blocks pressurized oil from port P (pilot pump). In addition, the output port is opened to port T (hydraulic oil tank) through the inner passage in spool (7).

2. Therefore, pressure in the output port is equal to that in port T. 3. When the control lever is slightly tilted, cam (1) is tilted and pusher (2) is pushed downward. Pusher (2) compresses return spring (6) along with spring guide (4) together.

4. At this time, as pressure in the output port is equal to that in port T, spool (7) moves downward due to the balance spring (5) force while keeping the lower surface of the spool (7) head in contact with spring guide (4).

T523-02-05-001 a-

5. This status continues until hole (8) on spool (7) is connected to port P.

T3-7-4

Pilot Pressure

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve

4 7

3 P

TNED-03-06-003

P-

Port P

T-

Port T

Output Port

12-

Cam Pusher

34-

Casing Spring Guide

56-

Balance Spring Return Spring

T3-7-5

TNED-03-06-004

78-

Spool Hole

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve During Metering or Decompressing (Output Curve: C to D) 1. When the control lever is further tilted and pusher (2) is moved downward further, hole (8) on spool (7) is connected to port P and pressurized oil in port P flows to the output port.

2. Pressure in the output port is routed to the bottom surface of spool (7) so that spool (7) is pushed upward. C

3. When the force to move spool (7) upward is smaller than the balance spring (5) force, balance spring (5) is not compressed so that spool (7) is not raised and pressure in the output port increases. 4. As pressure in the output port increases further, the force to move spool (7) upward increases. When this force overcomes the balance spring (5) force, spool (7) compresses balance spring (5) and moves upward.

T523-02-05-001 a-

5. As spool (7) is moved upward, hole (8) is closed so that pressurized oil from port P stops flowing to the output port and pressure in the output port stops increasing. 6. In this way, balance spring (5) is compressed by the amount that spool (7) is pushed down, and the pressure at output port (a) is the balanced pressure working on the spring force and spool (7).

T3-7-6

Pilot Pressure

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve

4 7

3 P

TNED-03-06-005

P-

Port P

T-

Port T

Output Port

12-

Cam Pusher

34-

Casing Spring Guide

56-

Balance Spring Return Spring

T3-7-7

TNED-03-06-006

78-

Spool Hole

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve Full Stroke (Output Curve: E to F) 1. When the control lever is fully stroked, the balance spring (5) force (force to push spool (7) downward) becomes larger than pressure in output port (a) (force to push spool (7) upward).

2. Therefore, even if pressure in output port (a) increases further, hole (8) on spool (7) is kept open. 3. Consequently, pressure in output port (a) is equal to that in port P.

T523-02-05-001 a-

T3-7-8

Pilot Pressure

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve

2 4 7

5 T

6 8 3 P

TNED-03-06-007

P-

Port P

T-

Port T

Output Port

12-

Cam Pusher

34-

Casing Spring Guide

56-

Balance Spring Return Spring

T3-7-9

78-

Spool Hole

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve Electromagnetic Detent 1. The coil for detent is installed in the pilot valve. 2. If the control lever is fully stroked, plate (9) is adsorbed by coil assembly (10). 3. Adsorption condition is retained until coil assembly (10) is unexcited or until adsorption is forcefully cancelled by operating the control lever toward the other direction.

TNED-03-06-007

Plate

10- Coil Assembly

T3-7-10

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve Outline (Fingertip Control Type Pilot Valve for Front Attachment) The pilot valve controls pilot pressurized oil in order to move the spool in the multiple control valve. The pilot valve outputs pressure according to the control lever stroke by PPC (Pressure Proportional Control Valve) function and moves the spool in the multiple control valve.

fNOTE: The fingertip control type pilot valve for the front attachment is optional.

Port No. 1 2 3 4

Bucket Dump Bucket Roll Back Lift Arm Lower Lift Arm Raise

Hydraulic Symbol

P T 1

T4GB-03-05-001

P-

T3-7-11

Port P (Pressurized Oil from Pilot Pump)

T4GB-03-05-002

T-

Port T (To Hydraulic Oil Tank)

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve Operation Neutral (Output Curve: A to B) 1. At the neutral position of the control lever, spool (7) is completely blocking the pressurized oil of port P. Also, outlet port (a) is connected to port T through notch part (b) of spool (7), and the pressurized oil at output port (a) is equal to the pressure in the hydraulic tank.

2. When the control lever is moved slightly, lever (1) is tilted, and push rod (2) and pusher (3) are pushed in. Pusher (3) and spring guide (4) remain mutually connected, and move downward, compressing return spring (6). 3. At this time, spool (7) is pushed by balance spring (5), and moves downward until clearance (A) becomes 0 mm.

T523-02-05-001 a-

4. During this movement, output port (a) remains connected with port T, and pressurized oil is not supplied to output port (a).

fNOTE: Lever stroke until clearance (A) becomes 0 mm is the play of the control lever.

T3-7-12

Pilot Pressure

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve  In neutral

1 2

4 5 6 T A

A b

7 a

T4GB-03-05-004

T4GB-03-05-003

P-

Port P (Pilot Pressurized Oil)

T-

Port T (To Hydraulic Oil Tank)

A-

Clearance

Notch Part

12-

Lever Push Rod

34-

Pusher Spring Guide

Output Port

56-

Balance Spring Return Spring

T3-7-13

Spool

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve Full Stroke (Output Curve: E to F)

During Metering or Pressure Decrease (Output Curve: C to D)

1. When the control lever is fully stroked, pusher (3) moves downward until spring guide (4) contacts the shoulder part of the casing.

1. When the control lever is further tilted, output port (a) is connected with port P through spool (7). 2. Pressurized oil from Port P flows into the output port through spool (7), and the pressure at output port (a) is raised.

2. At this time, spool (7) is directly pushed by the bottom of pusher (3). Even if the pressure at output port (a) is raised, spool (7) does not move upward. Therefore, output port (a) remains connected with port P through notch part (b) of spool (7).

3. Pressure in output port (a) works spool (7), and tends to push up spool (7).

3. Consequently, the pressure on the output port (a) end is equal to the pressure at port P. Stroke amount C of pusher (3) determines the total stroke of the lever.

4. When the force to move spool (7) upward is smaller than the balance spring (5) force, balance spring (5) is not compressed so that spool (7) is not raised and pressure in the output port (a) increases. 5. As pressure in the output port (a) increases further, the force to move spool (7) upward increases. When this force overcomes the balance spring (5) force, spool (7) compresses balance spring (5) and moves upward.

6. When spool (7) moves upward, output port (a) is not connected any longer, and pressurized oil stops flowing from port P to output port (a). Then, pressure increases at output port (a) is stopped. C

7. In this way, balance spring (5) is compressed by the amount that spool (7) is pushed down, and the pressure at output port (a) is the balanced pressure working on the spring force and spool (7).

T523-02-05-001 a-

T3-7-14

Pilot Pressure

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve  During Metering or Decompressing

 Full Stroke

4 b P

a P-

Port P (Pilot Pressurized Oil)

Notch Part

Pusher

T4GB-03-05-005

T-

Port T (To Hydraulic Oil Tank)

Output Port

C-

Pusher Stroke

Spring Guide

Balance Spring

Spool

T3-7-15

T4GB-03-05-006

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve Electromagnetic Detent  Fingertip Control Type Pilot Valve for Front Attachment 1. Coil for detent is installed at the push rod part of the pilot valve. 2. When one of the control levers is tilted, push rod (2) and plate (8) of the other are pushed upwards by the spring force. 3. If the control lever is operated until its stroke end, plate (8) of the other is adsorbed by coil assembly (10). 4. Adsorbed condition is retained until the coil assembly is unexcited or until adsorption is forcefully cancelled by moving the control lever the other way around.

90T4GB-03-05-07

Push Rod

Plate

10 - Coil Assembly

T3-7-16

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve Outline (Auxiliary Pilot Valve) (Option) The two-direction, four-port type (option) is adopted for the additional circuit pilot valve. Port No. 1 2

Option Option

T T

Hydraulic Symbol

P P

1 1

2 T554-02-07-009

1 P-

T3-7-17

T1LA-03-04-001

Port P (Pressurized Oil from Pilot Pump)

T-

Port T (To Hydraulic Oil Tank)

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve Operation Neutral (Output Curve: A to B) 1. At the neutral position of the control lever, spool (7) completely blocks the pressurized oil of port P. Also, outlet port (a) is connected to port T through passage (9) of spool (7), and the pressurized oil at output port (a) is equal to the pressure in the hydraulic tank.

p D

2. When the control lever is moved slightly, cam (1) is tilted. Then, pusher (2) and spring guide (4) remain mutually connected, compress return spring (6), and move downward. 3. At this time, spool (7) is pushed by balance spring (5) and moves downward until clearance (A) becomes 0 mm.

C A

b T1F3-03-09-004

4. During this movement, output port (a) remains connected with port T and pressurized oil is not supplied to output port (a).

fNOTE: Pedal stroke until clearance (A) becomes 0 mm is the play of the control lever.

T3-7-18

Pilot Pressure

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve Neutral (Output Curve: A to B)

1 2 3 4 5 T

6 A

A: 0 P

9 a

T1LA-03-04-003

T1LA-03-04-002

PA-

Port P Clearance

TB-

Port T Notch Part

Output Port

123-

Cam Pusher Plate

456-

Spring Guide Balance Spring Return Spring

789-

Spool Hole Part Passage

T3-7-19

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve During Metering or Decompressing (Output Curve: C to D) 1. When the control lever is further tilted, hole part (8) of spool (7) is connected to notch part (B).

2. Pressurized oil of port P flows to output port (a) through hole part (8) of spool (7) and pressure at output port (a) increases.

3. Pressure in output port (a) is routed to the bottom surface of spool (7) so that spool (7) is pushed upward.

b T1F3-03-09-004

6. As spool (7) is moved upward, notch part (B) is closed so that pressurized oil from port P stops flowing to output port (a) and pressure at output port (a) stops increasing. 7. In this way, balance spring (5) is compressed by the amount that spool (7) is pushed down, and the pressure at output port (a) is the balanced pressure working on the spring force and spool (7).

T3-7-20

Pilot Pressure

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve During Metering or Decompressing (Output Curve: C to D)

5 T B P

7 a

T1LA-03-04-004

PA-

Port P Clearance

TB-

Port T Notch Part

Output Port

123-

Cam Pusher Plate

456-

Spring Guide Balance Spring Return Spring

789-

Spool Hole Part Passage

T3-7-21

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve (Blank)

T3-7-22

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve Outline (Auxiliary Pilot Valve) (Option) The joystick type (four-direction, four-port type) (option) is adopted for the additional circuit pilot valve. Port No. 1 2 3 4

Option Option Option Option

Hydraulic Symbol P

3 1

4 T105-02-07-020

T1V1-03-04-001 T P-

T3-7-23

Port P (Pressurized Oil from Pilot Pump)

T-

Port T (To Hydraulic Oil Tank)

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve Operation The spool (6) head comes in contact with the upper surface of spring guide (3). Spring guide (3) is kept raised by return spring (5). Neutral (Output Curve: A to B) 1. When in neutral, spool (6) completely blocks pressurized oil from port P (pilot pump). In addition, output port (a) is opened to port T (hydraulic oil tank) through the inner passage in spool (6).

2. Therefore, pressure in output port (a) (to the multiple control valve) is equal to that in port T.

3. When the control lever is slightly tilted, cam (1) is tilted and pusher (2) is pushed downward. Pusher (2) compresses return spring (5) along with spring guide (3) together.

4. At this time, as pressure in output port (a) is equal to that in port T, spool (6) moves downward due to the balance spring (4) force while keeping the lower surface of the spool (6) head in contact with spring guide (3).

T523-02-05-001 p-

5. This status continues until hole (7) on spool (6) is connected to port P.

T3-7-24

Pilot Pressure

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve

2 6

6 P a

T1V1-03-04-007

P-

Port P

T-

Port T

Output Port

12-

Cam Pusher

34-

Spring Guide Balance Spring

56-

Return Spring Spool

T3-7-25

T1V1-03-04-008

Hole

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve During Metering or Decompressing (Output Curve: C to D) 1. When the control lever is further tilted and pusher (2) is moved downward further, hole (7) on spool (6) is connected to port P and pressurized oil in port P flows to output port (a).

2. Pressure in output port (a) is routed to the bottom surface of spool (6) so that spool (6) is pushed upward.

3. When the force to move spool (6) upward is smaller than the balance spring (4) force, balance spring (4) is not compressed so that spool (6) is not raised and pressure in output port (a) increases. 4. As pressure in the output port (a) increases further, the force to move spool (6) upward increases. When this force overcomes the balance spring (4) force, spool (6) compresses balance spring (4) and moves upward.

T523-02-05-001 p-

5. As spool (6) is moved upward, hole (7) is closed so that pressurized oil from port P stops flowing to output port (a) and pressure in output port (a) stops increasing. 6. In this way, balance spring (4) is compressed by the amount that spool (6) is pushed down, and the pressure at output port (a) is the balanced pressure working on the spring force and spool (6).

T3-7-26

Pilot Pressure

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve

6 T

T1V1-03-04-009

P-

Port P

T-

Port T

Output Port

12-

Cam Pusher

34-

Spring Guide Balance Spring

56-

Return Spring Spool

T3-7-27

T1V1-03-04-010

Hole

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve Full Stroke (Output Curve: E to F) 1. When the control lever is fully stroked, pusher (2) moves downward until it comes in contact with the shoulder part of the casing.

2. At this time, spool (6) is directly pushed by the bottom of pusher (2). Therefore, even if pressure in output port (a) increases further, hole (7) on spool (6) is kept open.

3. Consequently, pressure in output port (a) is equal to that in port P.

fNOTE: Total lever stroke is determined by stroke

dimension (E) of pusher (2).

T523-02-05-001 p-

T3-7-28

Pilot Pressure

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve

1 2

3 4 5

6 T P

T1V1-03-04-011

T1V1-03-04-007

P-

Port P

T-

Port T

Output Port

E-

Pusher Stroke

12-

Cam Pusher

34-

Spring Guide Balance Spring

56-

Return Spring Spool

Hole

T3-7-29

SECTION 3 COMPONENT OPERATION Group 7 Pilot Valve (Blank)

T3-7-30

SECTION 3 COMPONENT OPERATION Group 8 Brake Charge Valve Outline The charging circuit consists of brake charge valve (3) and manifold valve (1). (Refer to SYSTEM / Hydraulic System.) Brake charge valve (3) makes the accumulated pressure in service brake accumulator (5) to the set pressure. Brake charge valve (3) supplies pressurized oil from the pilot pump preferentially to the brake circuit. In addition, when the accumulated pressure in service brake accumulator (5) is kept at the set pressure, it supplies pressurized oil to manifold valve (1) and the fan circuit. Pressure sensor (brake primary pressure) (4) is installed in brake charge valve (3) in order to control the brake.

5 7 4

TNDF-03-08-001

12-

Manifold Valve Pressure Sensor (Primary Pilot Pressure)

34-

Brake Charge Valve Pressure Sensor (Brake Primary Pressure)

567-

T3-8-1

Service Brake Accumulator Pilot Accumulator Pressure Sensor (Parking Brake)

Parking Brake Accumulator

SECTION 3 COMPONENT OPERATION Group 8 Brake Charge Valve Brake Charge Valve The brake charge valve supplies pressurized oil from the pilot pump to the service brake accumulator, brake valve, manifold valve, and fan valve.

Operation

 Between pressure accumulation start and finish 1. When the pressure of service brake accumulators (17, 18) decrease below the specified value, the passage (5) pressure also decreases. Pilot piston (7) is moved down (up on the circuit diagram) by the spring (8) force.

16 d

19 15

4 5 6 7

2. Therefore, the passage (14) pressure increases slowly as passage (14) and port T are blocked by pilot piston (7).

3. When the passage (14) pressure is under the condition that the passage (14) pressure and the spring (13) force are larger than the oil chamber (11) pressure, priority valve (brake) (12) moves to the right. 4. Pressurized oil from port P pushes to open check valve (9) and flows to service brake accumulators (17, 18) and brake valves (a, b). 5. At this time, the pressure difference is generated between service brake accumulators (17, 18) and spool (3) moves to the pressure-low side. 6. Therefore, pressurized oil is supplied to either of service brake accumulators (17, 18) whose pressure is lower. 7. Then, pressurized oil is supplied preferentially and it is accumulated in the accumulator so that the pressure of service brake accumulators (17, 18) can be kept over the specified value. 8. This operation continues until the accumulator pressure increases and reaches the cutout pressure.

8 9 10 P

11 TNED-03-07-015

abcd-

To Brake Valve (Port PA) To Brake Valve (Port PB) To Fan Valve (Port P) To Manifold Valve (Port P)

123456789101112-

Orifice Orifice Spool Spring Passage Piston Pilot Piston Spring Check Valve Orifice Oil Chamber Priority Valve (Brake)

T3-8-2

1314151617-

Spring Passage Orifice Spring Service Brake Accumulator (Front) 18- Service Brake Accumulator (Rear) 19- Pressure Sensor (Brake Primary Pressure)

SECTION 3 COMPONENT OPERATION Group 8 Brake Charge Valve Section A-A

14 13

12 P

7 B

f Section B-B

4 C

9 g A

Section C-C

TNED-03-07-017

3 PT-

Port P (From Pilot Pump) Port T (To Hydraulic Oil Tank)

abc-

To Brake Valve (Port PA) To Brake Valve (Port PB) To Fan Valve (Port P)

de-

To Manifold Valve (Port P) Service Brake Accumulator (Front) Mounting Port

Service Brake Accumulator (Rear) Mounting Port

Pressure Sensor (Brake Primary Pressure) Mounting Port

1234-

Orifice Orifice Spool Spring

5678-

Passage Piston Pilot Piston Spring

9101112-

Check Valve Orifice Oil Chamber Priority Valve (Brake)

13141516-

Spring Passage Orifice Spring

T3-8-3

SECTION 3 COMPONENT OPERATION Group 8 Brake Charge Valve  After pressure accumulation finish 1. Pressurized oil in passage (5) is routed to piston (6). 2. In addition, the pressure of service brake accumulators (17, 18) are blocked by check valve (9) and are kept.

3. When the accumulator pressure reaches the cutout pressure, pilot piston (7) is moved up (down on the circuit diagram) by the passage (5) force.

3 16

4. Passage (14) is connected to port T (hydraulic oil tank) so that the passage (14) pressure decreases.

5. Therefore, when the passage (14) pressure and the spring (13) force is smaller than the oil chamber (11) pressure, priority valve (brake) (12) moves to the left.

4 5 6 7

14 13

8 9 10

6. Consequently, pressurized oil in port P is supplied to brake valves (a, b), manifold valve (d), and fan valve (c).

7. This operation continues until the service brake is applied (the brake circuit pressure decreases).

11 TNED-03-07-015

abcd-

To Brake Valve (Port PA) To Brake Valve (Port PB) To Fan Valve (Port P) To Manifold Valve (Port P)

123456789101112-

Orifice Orifice Spool Spring Passage Piston Pilot Piston Spring Check Valve Orifice Oil Chamber Priority Valve (Brake)

T3-8-4

1314151617-

Spring Passage Orifice Spring Service Brake Accumulator (Front) 18- Service Brake Accumulator (Rear)

SECTION 3 COMPONENT OPERATION Group 8 Brake Charge Valve Section A-A

14 13

12 P

7 B

f Section B-B

4 C

9 g A

Section C-C

TNED-03-07-017

3 c-

To Manifold Valve

PT-

Port P (From Pilot Pump) Port T (To Hydraulic Oil Tank)

abc-

To Brake Valve (Port PA) To Brake Valve (Port PB) To Fan Valve (Port P)

de-

To Manifold Valve (Port P) Service Brake Accumulator (Front) Mounting Port

Service Brake Accumulator (Rear) Mounting Port

Pressure Sensor (Brake Primary Pressure) Mounting Port

1234-

Orifice Orifice Spool Spring

5678-

Passage Piston Pilot Piston Spring

9101112-

Check Valve Orifice Oil Chamber Priority Valve (Brake)

13141516-

Spring Passage Orifice Spring

T3-8-5

SECTION 3 COMPONENT OPERATION Group 8 Brake Charge Valve (Blank)

T3-8-6

SECTION 3 COMPONENT OPERATION Group 9 Manifold Valve Outline Manifold valve (1) reduces pressure of pressurized oil from brake charge valve (3) and supplies it to each pilot circuit. Manifold valve (1) supplies pressurized oil from brake charge valve (3) to the exhaust filter regeneration/ quick coupler circuit (OPT) and the ride control circuit. In addition, pressurized oil is supplied to lift arm, bucket operation control circuits and the parking brake due to the controls of the control lever lock solenoid valve and parking brake solenoid valve.

Pressure sensor (primary pilot pressure) (2) and pressure sensor (parking brake) (7) are installed in manifold valve (1) in order to control the control lever lock indicator and the parking brake respectively.

5 7 4

TNDF-03-08-001

12-

Manifold Valve Pressure Sensor (Primary Pilot Pressure)

34-

Brake Charge Valve Pressure Sensor (Brake Primary Pressure)

56-

T3-9-1

Service Brake Accumulator Pilot Accumulator

78-

Pressure Sensor (Parking Brake) Parking Brake Accumulator

SECTION 3 COMPONENT OPERATION Group 9 Manifold Valve Manifold Valve 1

The manifold valve consists of pilot reducing valve (1), parking brake solenoid valve (2), control lever lock solenoid valve (3), parking brake accumulator (5), and pilot accumulator (front) (4). Pilot reducing valve (1) keeps pressurized oil (a) to the specified pressure.

Parking brake solenoid valve (2) supplies or does not supply parking brake release pressurized oil to parking brake (b) according to shifting the parking brake switch. Control lever lock solenoid valve (3) supplies or does not supply pilot pressurized oil to the lift arm, bucket operation control circuits according to shifting the control lever lock switch. Parking brake accumulator (5) keeps parking brake release pressure. Pilot accumulator (front) (4) keeps the pressure in the lift arm, bucket operation control circuits.

12 5

ab-

1234567-

T3-9-2

From Brake Charge Valve To Parking Brake

Pilot Reducing Valve Parking Brake Solenoid Valve Control Lever Lock Solenoid Valve Pilot Accumulator (Front) Parking Brake Accumulator Pressure Sensor (Primary Pilot Pressure) Pressure Sensor (Parking Brake)

TNDF-03-09-001

To Exhaust Filter Regeneration, Quick Coupler (OPT), and Ride Control Circuits (OPT) To Pilot Valve

8910111213-

Port P Port DR1 Port PS1 Port PP1 Port BR Port DR2

SECTION 3 COMPONENT OPERATION Group 9 Manifold Valve

2 7

TNDF-03-09-002

123-

Pilot Reducing Valve Parking Brake Solenoid Valve Control Lever Lock Solenoid Valve

45-

Port A1 (Pilot Accumulator (Front)) Port A2 (Parking Brake Accumulator)

678-

T3-9-3

Port S1 (Pressure Sensor (Primary Pilot Pressure)) Port S2 (Pressure Sensor (Parking Brake)) Port P

910111213-

Port DR1 Port PS1 Port PP1 Port BR Port DR2

SECTION 3 COMPONENT OPERATION Group 9 Manifold Valve Pilot Reducing Valve Pilot reducing valve (1) controls the pressure at the port P (4) side and reduces the pressure of oil from port P (4) to the specified pressure. Operation 1. The oil passage between port P (4) and port PS1 (6) is connected by spool (3). The oil passage between port PS1 (6) and port DR1 (5) is disconnected. Pressurized oil from port P (4) flows to port PS1 (6) through spool (3). 2. Force F (force to push upward) (Pressure in Port PS1 (6) x Pressurized Area of Spool (3)) is routed to spool (3). 3. When pressure in port PS1 (6) increases and force F routed to spool (3) is stronger than the spring (2) force, spool (3) compresses spring (2) and moves upward. 4. Therefore, the oil passage between port P (4) and port PS1 (6) is disconnected and the oil passage between port PS1 (6) and port DR1 (5) is connected. Then, pressure in port PS1 (6) decreases. 5. When pressure in port PS1 (6) decreases, spool (3) is moved down by the spring (2) force. 6. The above operation is repeated so that pressure in port PS1 (6) is kept in order to become balanced with the spring (2) force. 7. Consequently, pressurized oil from port P (4) is kept constant and is supplied to each pilot circuit.

T3-9-4

SECTION 3 COMPONENT OPERATION Group 9 Manifold Valve

TNDF-03-09-003

Section A-A

5 3 4

TNDF-03-09-004

123-

Pilot Reducing Valve Spring Spool

45-

Port P (From Brake Charge Valve) Port DR1 (To Hydraulic Oil Tank)

T3-9-5

To Port PS1 (To Exhaust Filter Regeneration, Quick Coupler (OPT), and Ride Control Circuits (OPT))

SECTION 3 COMPONENT OPERATION Group 9 Manifold Valve Parking Brake Solenoid Valve Parking brake solenoid valve (1) supplies pilot pressurized oil (parking brake release pressurized oil) to the parking brake when the parking brake switch is in the OFF position. Parking brake solenoid valve (1) is an ON/OFF solenoid valve. Operation:  Solenoid: OFF (Parking Brake Switch: ON Position) 1. Spool (3) has been moved to the left by the spring (4) force. 2. As the oil passage of port BR (7), port DR2 (6), and port S2 (8) is connected, the pressure in the circuit becomes equal to that in the hydraulic oil tank. 3. Pilot pressurized oil from port P (5) is blocked by spool (3). 4. Therefore, returning oil from the parking brake flows to port DR2 (6) through port BR (7) and spool (3), and returns to the hydraulic oil tank.  Solenoid: ON (Parking Brake Switch: OFF Position) 1. Spool (3) is moved to the right by push rod (9) in the solenoid. 2. As the oil passage of port P (5), port BR (7), and port S2 (8) is connected, the pressure in the circuit becomes the set pressure of the pilot reducing valve. 3. Therefore, pilot pressurized oil from port P (5) flows to port BR (7) through spool (3), and is routed to the parking brake.

T3-9-6

SECTION 3 COMPONENT OPERATION Group 9 Manifold Valve

Section B-B OFF (Parking Brake Switch: ON Position)

3 2

1 B

TNDF-03-09-006

ON (Parking Brake Switch: OFF Position)

3 2

TNDF-03-09-005

123-

Parking Brake Solenoid Valve Solenoid Spool

45-

Spring Port P (From Brake Charge Valve)

67-

T3-9-7

Port DR2 (To Hydraulic Oil Tank) Port BR (To Parking Brake)

89-

TNDF-03-09-006

Port S2 (Pressure Sensor (Parking Brake)) Push Rod

SECTION 3 COMPONENT OPERATION Group 9 Manifold Valve Control Lever Lock Solenoid Valve Control lever lock solenoid valve (1) is shifted by the control lever lock switch and supplies pilot pressurized oil to the pilot valve. Control lever lock solenoid valve (1) is an ON/OFF solenoid valve. Operation:  Solenoid: OFF (Control Lever Lock Switch: ON Position) 1. Spool (3) has been moved to the left by the spring (4) force. 2. As the oil passage of port PP1 (10), port S1 (10), and port DR2 (6) is connected, the pressure in the circuit becomes equal to that in the hydraulic oil tank. 3. Pilot pressurized oil from port P (5) is blocked by spool (3) and is not supplied to the pilot valve. 4. Therefore, returning oil from the pilot valve flows to port DR2 (6) through port PP1 (10) and spool (3), and returns to the hydraulic oil tank.  Solenoid: ON (Control Lever Lock Switch: OFF Position) 1. Spool (3) is moved to the right by push rod (9) in the solenoid. 2. As the oil passage of port P (5), port PP1 (10), and port S1 (10) is connected, the pressure in the circuit becomes the set pressure of the pilot reducing valve. 3. Therefore, pilot pressurized oil from port P (5) flows to port PP1 (10) through spool (3), and is routed to the pilot valve.

T3-9-8

SECTION 3 COMPONENT OPERATION Group 9 Manifold Valve

Section C-C OFF (Front Control Lever Lock Switch: ON Position)

2 C

TNDF-03-09-007

C ON (Front Control Lever Lock Switch: OFF Position)

1 6

TNDF-03-09-005

123-

Front Control Lever Lock Solenoid Valve Solenoid Spool

45-

Spring Port P (From Brake Charge Valve)

69-

T3-9-9

Port DR2 (To Hydraulic Oil Tank) Push Rod

TNDF-03-09-007

10- Port PP1 (Pilot Valve)/ Port S1 (Pressure Sensor (Primary Pilot Pressure))

SECTION 3 COMPONENT OPERATION Group 9 Manifold Valve Pilot Accumulator The pilot accumulator is installed in the manifold valve for the parking brake and the front attachment. High-pressure nitrogen gas (1) is contained in the accumulator, and pressurized oil from the pilot pump compresses nitrogen gas (1) through bladder (2). The each circuit pressurized oil is retained by compression of nitrogen gas (1).

IMPORTANT: The pilot accumulator cannot be disassembled due to structural problem. Replace it as an assembly if necessary.

T1F3-03-08-007 a

Pressurized Oil from Pilot Pump

Nitrogen Gas

Bladder

T3-9-10

SECTION 3 COMPONENT OPERATION Group 10 Transmission Outline Transmission (3) consists of the motor 1 input shaft, the motor 1 input gear, the motor 2 input shaft, the motor 2 input gear, the clutch shaft, the clutch shaft gear, the clutch shaft hub gear, the output shaft, and the output gear.

When the machine travels at slow speed (1st speed, 2nd speed), the transmission transmits the power from HST motor 1 (1) and HST motor 2 (2) to the output shaft together. When the machine travels at fast speed (3rd speed, 4th speed), the transmission disconnects the power from HST motor 1 (1) and transmits power only from HST motor 2 (2) to the output shaft.

Clutch pressure control valve (4), parking brake (5), the machine speed 1 sensor, and the machine speed 2 sensor are provided in order to control the transmission.

fNOTE: HST stands for hydrostatic transmission.

5 2 1

12-

HST Motor 1 HST Motor 2

Transmission

T3-10-1

Clutch Pressure Control Solenoid Valve

TNDF-03-02-001

Parking Brake

SECTION 3 COMPONENT OPERATION Group 10 Transmission Transmission Hydraulic Circuit Diagram

6 a

7 8 9 10 11

12 13

18 16

ab-

12345-

From Manifold Valve (Port BR) Lubrication Circuit

HST Motor 1 HST Motor 2 Transmission Vehicle Speed 1 Sensor Motor 2 Input Gear

From Transmission Charge Pump To Transmission Charge Pump

678910-

Motor 2 Input Shaft Parking Brake Output Gear Output Shaft Clutch Shaft Hub Gear

11- Clutch Shaft Gear 12- Clutch Shaft 13- Clutch Pressure Control Solenoid Valve 14- Motor 1 Input Gear

T3-10-2

Parking Brake Release Pressure Port HST Motor 1 Mounting Part

T4FC-03-10-001

HST Motor 2 Mounting Part

15161718-

Motor 1 Input Shaft Oil Pan Vehicle Speed 2 Sensor Clutch

SECTION 3 COMPONENT OPERATION Group 10 Transmission Layout of Transmission 13 e

14 f

TNDF-03-10-004

3 8

5 6

Cross Section A-A W4FC-03-04-013

T3-10-3

SECTION 3 COMPONENT OPERATION Group 10 Transmission Clutch Shaft Part

W4FC-03-04-024

12-

Plate Return Spring

34-

Disc Clutch Piston

56-

T3-10-4

Bleed Valve Shaft

Clutch Shaft Hub Gear

SECTION 3 COMPONENT OPERATION Group 10 Transmission Clutch Pressure Control Solenoid Valve 1

a B

C d

Section B-B

Section C-C

From Transmission Charge Pump

Clutch Circuit Connecting Port

Lubrication Circuit Connecting Port

12-

Proportional Solenoid Valve Piston

34-

Spring Spring

56-

Spool Spring

T3-10-5

Valve Piston

T4FC-03-10-005

SECTION 3 COMPONENT OPERATION Group 10 Transmission Power Transmission Power Transmission (At Slow Speed) Clutch (18) is connected when the machine travels at slow speed (1st speed, 2nd speed). The power from HST motor 1 (1) is transmitted to output gear (8) through motor 1 input gear (14), clutch shaft gear (11), and clutch shaft hub gear (10). The power from HST motor 2 (2) is transmitted to output gear (8) through motor 2 input gear (5). The power from HST motor 1 (1) and HST motor 2 (2) are merged by output gear (8).

10 11

14 T4FC-03-10-002

123-

HST Motor 1 HST Motor 2 Transmission

5- Motor 2 Input Gear 8- Output Gear 10- Clutch Shaft Hub Gear

11- Clutch Shaft Gear 14- Motor 1 Input Gear 18- Clutch

T3-10-6

SECTION 3 COMPONENT OPERATION Group 10 Transmission Power Transmission (At Fast Speed) Clutch (18) is disconnected when the machine travels at fast speed (3rd speed, 4th speed). Therefore, the power from HST motor 1 (1) is not transmitted to output gear (8). The power from HST motor 2 (2) is transmitted to output gear (8) through motor 2 input gear (5).

14 T4FC-03-10-003

12-

HST Motor 1 HST Motor 2

35-

Transmission Motor 2 Input Gear

8- Output Gear 14- Motor 1 Input Gear

T3-10-7

18- Clutch

SECTION 3 COMPONENT OPERATION Group 10 Transmission Clutch Operation

 When clutch is disconnected: 1. When pressurized oil (P) is not supplied from the clutch pressure control solenoid valve, bleed valve (5) is opened by the centrifugal force of shaft (6). Therefore, the residual pressure in the piston is discharged to disc (3) side.

 When clutch is connected: 1. The clutch is operated by pressurized oil (P) from the clutch pressure control solenoid valve. 2. Pressurized oil (P) from the clutch pressure control solenoid valve reaches the back of clutch piston (4) through the oil passage in shaft (6).

2. Clutch piston (4) is pushed back by return springs (2) between plates (1).

3. As pressurized oil (P) pushes bleed valve (5) in clutch piston (4) toward disc (3), the oil passage is blocked. Therefore, clutch piston (4) is pushed toward disc (3).

3. As a clearance is generated between disc (3) and plate (1), shaft (6) and clutch shaft hub gear (7) rotate separately so that the power is not transmitted.

4. Clutch piston (4) transmits the power to the whole of shaft (6) and clutch shaft hub gear (7) connected by pushing disc (3) and plate (1) tightly.

W4FC-03-04-024

P-

Pressurized Oil from Clutch Pressure Control Solenoid Valve

12-

Plate Return Spring

34-

Disc Clutch Piston

56-

T3-10-8

Bleed Valve Shaft

Clutch Shaft Hub Gear

SECTION 3 COMPONENT OPERATION Group 10 Transmission When clutch is connected: 1

7 5

Enlarged A

T4FC-03-10-007

When clutch is disconnected: 1

7 5

Enlarged B

T4FC-03-10-006

12-

Plate Return Spring

34-

Disc Clutch Piston

56-

T3-10-9

Bleed Valve Shaft

Clutch Shaft Hub Gear

SECTION 3 COMPONENT OPERATION Group 10 Transmission Clutch Pressure Control Solenoid Valve The clutch pressure control solenoid valve consists of the valve body, proportional solenoid valve (1), spring (3), and spool (2). The clutch pressure control solenoid valve supplies pressurized oil from the transmission charge pump to the clutch through proportional solenoid valve (1). In addition, regulator (4) keeps pressurized oil from the transmission charge pump constant and supplies extra pressurized oil to lubrication circuit (d).

 When operated: 1. Pressurized oil from the transmission charge pump is routed to proportional solenoid valve (1). 2. When proportional solenoid valve (1) receives the signal from the HST controller, it opens the oil passage. Pressurized oil through the oil passage is routed to spool (2). 3. When pressurized oil routed to spool (2) is stronger than the spring (3) force, spool (2) is moved to the right (to the left as illustrated in the circuit diagram). 4. Therefore, the oil passage between clutch circuit (a) and the transmission charge pump is connected. Pressurized oil is supplied to clutch circuit (a). 5. Consequently, the clutch is connected.  When not operated: 1. When proportional solenoid valve (1) does not receive the signal from the HST controller, it keeps the oil passage closed. 2. As pressurized oil from the transmission charge pump is not routed to spool (2), spool (2) is moved to the left (to the right as illustrated in the circuit diagram) by the spring (3) force. 3. Therefore, the oil passage between clutch circuit (a) and oil pan (b) is connected. Pressurized oil is discharged from clutch circuit (a). 4. Consequently, the clutch is disconnected.

f NOTE: The illustration shows the oil flow when not operated.

T3-10-10

d b

4 P

T4FC-03-10-011

SECTION 3 COMPONENT OPERATION Group 10 Transmission When operated: 1

TNDF-03-10-008

When not operated: 1

P-

Pressurized Oil from Transmission Charge Pump

ab-

Clutch Circuit Oil Pan

Proportional Solenoid Valve

Spool

Spring

T3-10-11

T4FC-03-10-008

Regulator

SECTION 3 COMPONENT OPERATION Group 10 Transmission Regulator Regulator (4) keeps pressurized oil (P) from the transmission charge pump constant pressure. In addition, it supplies extra pressurized oil to lubrication circuit (d). Pressurized oil (P) from the transmission charge pump is routed to valve piston (2). When pressurized oil (P) overcomes the spring (3) force, valve piston (2) is moved to the right. Consequently, pressurized oil (P) from the transmission charge pump is kept constant. This function allows overflowing pressurized oil to use as lubricant. Overflowing pressurized oil is supplied to each part in the transmission through lubrication circuit (d).

T3-10-12

TNDF-03-10-001

SECTION 3 COMPONENT OPERATION Group 10 Transmission

P-

Pressurized Oil from Transmission Charge Pump

ab-

Clutch Circuit Oil Pan

Lubrication Circuit

Regulator

Valve Piston

Spring

T3-10-13

TNDF-03-10-002

SECTION 3 COMPONENT OPERATION Group 10 Transmission Proportional Solenoid Valve The proportional solenoid valve is controlled by the electric current signal from the HST controller and outputs pressure in proportion to the electric current. NOTE: As pressure in proportion to the electric current is output, the shock during clutch control is reduced.

 When in neutral 1. Spring (2) pushes spool (1) to the right and output port S is connected to tank port T.

 When excited 1. Solenoid (3) pushes spool (1) to the left in proportion to the current value flowing through solenoid (3). 2. Pilot pressurized oil from port P flows to output port S and pressure at output port S increases. 3. This pressure at output port S is routed to stepped part a of spool (1). Spool (1) is pushed to the right due to difference in the pressure receiving area between stepped part a. 4. When pressure at output port S increases and the force to push spool (1) to the right overcomes the force to push spool (1) to the left by solenoid (3), spool (1) is moved back to the right and the passage between output port S and port P is closed. Therefore, pressure at output port S stops increasing.

T3-10-14

SECTION 3 COMPONENT OPERATION Group 10 Transmission

S b

P c

c TNDF-03-10-003 a-

From Pressurized Oil from Transmission Charge Pump

bP-

To Valve Body Spool Port P

ST-

Output Port S Tank Port T

Spool

Spring

Solenoid

T3-10-15

SECTION 3 COMPONENT OPERATION Group 10 Transmission Parking Brake The parking brake is a wet-type spring set hydraulic released multi-disc brake. The parking brake consists of brake housing (3), brake piston (5), spring (6), brake plate (1), brake disc (2), and end plate (4). The parking brake solenoid valve is provided outside in order to control the parking brake. (Refer to Manifold Valve.) The parking brake is installed to motor 2 input shaft (8) of the transmission through disc hub (7). When pilot pressurized oil is routed, the parking brake is released.

4 a

5 6

7 T4FC-03-10-009

Parking Brake Solenoid Valve

Oil Chamber

12-

Brake Plate Brake Disc

34-

Brake Housing End Plate

56-

Brake Piston Spring

T3-10-16

78-

Disc Hub Motor 2 Input Shaft

SECTION 3 COMPONENT OPERATION Group 10 Transmission When parking brake is applied:

1. Brake disc (2) is connected to motor 2 input shaft (8) through disc hub (7) by spline joint. Brake disc (2) also rotates in response to the rotation of motor 2 input shaft (8). In addition, the outer surface of brake plate (1) is fixed to brake housing (3).

2 b

5 6

2. When the parking brake switch is set to the ON position, pilot pressurized oil is blocked by the parking brake solenoid valve and is not routed to oil chamber (b) in brake piston (5). 3. Brake piston (5) is moved to the left by the spring (6) force. 4. Therefore, as brake disc (2) and brake plate (1) are compressed tightly, brake disc (2) is fixed. 5. Consequently, the rotation of motor 2 input shaft (8) is stopped so that the parking brake is applied.

T4FC-03-10-010

When parking brake is released:

1. When the parking brake switch is set to the OFF position, pilot pressurized oil from the parking brake solenoid valve is routed to oil chamber (b) in brake piston (5).

2. When the pressure in oil chamber (b) is stronger than the spring (6) force, brake piston (5) is moved to the right. 3. Therefore, as brake disc (2) is released from brake plate (1), brake disc (2) becomes free. 4. Consequently, motor 2 input shaft (8) can rotate so that the parking brake is released.

T3-10-17

T4FC-03-10-010

SECTION 3 COMPONENT OPERATION Group 10 Transmission (Blank)

T3-10-18

SECTION 3 COMPONENT OPERATION Group 11 Axle Outline Axle consists of differential (3), final drive (2), axle shaft (1), brake (4), and other driveline parts.

Power from the transmission is transmitted to the front axle and the rear axle through the propeller shaft. Inside the axle, power is transmitted to differential (3), and divided to the left and right sides, and drives axle shaft (1) and the wheels through final drive planetary (2).

TNDF-03-11-001

Axle Shaft

Final Drive

fNOTE: The illustration shows the front axle.

T3-11-1

Differential

Brake

SECTION 3 COMPONENT OPERATION Group 11 Axle Differential The differential enables the left and right drive wheels to rotate at different speeds while steering and traveling on uneven surface.

TNDF-03-11-002 Machine Front Side

12345-

Flange Yoke Oil Seal Cage Shim Taper Roller Bearing

678910-

Spacer Collar Drive Pinion Case Pilot Bearing Nut

1112131415-

T3-11-2

Taper Roller Bearing Adjusting Nut Side Gear Thrust Washer (Side Gear) Pinion Gear

16171819-

Thrust Washer (Pinion Gear) Ring Gear Spider Snap Ring

SECTION 3 COMPONENT OPERATION Group 11 Axle Purpose of Differential 1. When the machine is steered, the inner wheel turns with a smaller radius, so the outer wheel needs to rotate faster for smooth steering. 2. Suppose driving the rear wheel by directly installing the gear to the propeller shaft with a shaft having no differential. 3. In this case, the outer wheel and the inner wheel rotate at the same rate. Therefore, when the machine is steered, the outer wheel cannot rotate more than the inner wheel. Consequently, axle strain, tire scuffing and wear takes place. In addition, due to axle shaft torsional stress and unstable transmission of drive force take place. 4. On the other hand, with a differential installed, the inner and the outer wheels can rotate at different speeds, and the problem mentioned above is eliminated.

c T202-03-05-005

Extension Line of Rear Wheel Centers

While Turning the Machine

T3-11-3

Traveling on Rough Surfaces

SECTION 3 COMPONENT OPERATION Group 11 Axle Principle of Differential Operation principle of the differential is explained here comparing it to the racks and the pinion gear in the drawing. W

1. When the load W is equally applied to rack A (1) and rack B (3), and if C is moved upward by the distance of H, rack A (1) and rack B (2) both move the same distance of H in unison with pinion (2).

W C

C H

2. If moved by removing the load from rack B (3), pinion (2) rotates on rack A (1) (with load applied) and moves upward.

3. Rack B (3) (with light load applied) moves upward by rotating pinion (2). 4. At this time, the distance that rack B (3) moves is longer than the distance that pinion (2) moves while rotating.

5. The distance that rack B (3) moves can be calculated using the equation of H+H=2H. This principle is applied to the differential.

2 T202-03-05-006

12-

T3-11-4

Rack A Pinion

Rack B

SECTION 3 COMPONENT OPERATION Group 11 Axle Operation of Differential  Traveling Straight 1. In case resistances applied to axle shafts (1, 7) connected to side gear (2) by spline joint are the same or when the machine is traveling straight on a smooth flat surface, idle gear (4) does not rotate.

2. Idle gear (4) and side gear (2) are proportionally "geared together", and rotate in unison with half case (6) and half gear (3)which are connected to ring gear (8).

9 4

3. When the rate of movement of each wheel is identical on each side, the differential function of the differential does not need to work, but side gear (2), idle gear (4), and spider (5) play only the role of joints for connecting axle shafts (1, 7).

 When Steering 4. When the machine turns, uneven distances are applied to the drive wheels. Therefore, idle gear (4) begins revolving on side gear (2) while rotating around spider (5) due to the difference of the distances applied to the left and right tires.

T202-03-05-007

5. Consequently, in case the resistance force applied to axle shaft (1) is great, idle gear (4) rotates in the same direction as the rotational direction on side gear (2). And the speed of axle shaft (1) is lowered and the amount of the speed reduction is applied to axle shaft (7), working the differential function. 6. Suppose ring gear (8) is driven by pinion shaft (9) at the speed of 100. In the condition that the vehicle body is traveling straight, the drive wheels on the both sides rotate at the same speed. 7. When the machine turns and the speed of the right drive wheel is lowered to 90, the left wheel turns at the speed of 100+(100-90)=110 as the speed of 10 (100-90=10) is added to the speed of the left wheel. 8. If ring gear (8) rotates at the speed of 100, the summation of the speeds of the left and right wheels becomes always 200 regardless of movement of the respective wheels.

T3-11-5

9 4

2 6

T202-03-05-008

SECTION 3 COMPONENT OPERATION Group 11 Axle Torque Proportioning Differential (TPD) A wheel loader is operated mostly on rough surfaces. With scuffing of tires, working efficiency and tire life is lessened. In order to avoid loss of working efficiency and tire life, the axle is provided with the torque proportioning differential. Differential pinion gear (2) of the torque proportioning differential has an odd number of teeth, and differential pinion gear (2) and side gears (1, 3) have special teeth in shape. If the surface resistance values of the right and left wheels differ from each other, engagement position of pinion gear (2) with left and right side gears (1, 3) will be automatically shifted to transmit different torque, to the left and right wheels. Different torque in right and left wheels prevents the tires from slipping.

Forward Rotation

Left Side Gear

Differential Pinion Gear

T487-03-06-015

T3-11-6

Right Side Gear

SECTION 3 COMPONENT OPERATION Group 11 Axle Traveling Straight with the Same Road Resistances to Left and Right Tires 1. In case resistances to the left and right tires are the same, distance a and distance b from differential pinion gear (2) center to the respective contact points of left and right side gears (1, 3) are the same.

2. Therefore, differential pinion gear (2) and left and right side gears (1, 3) solidly rotate toward forward, and the drive forces of the left and right tires are the same. T487-03-06-016

Traveling on Soft Roads (Different Road Resistances to Left and Right Tires) 1. While traveling on soft roads, if the left tire slips, left side gear (1) on the left tire receiving little resistance tends to rotate more forward than right side gear (3). 2. This rotation causes deviation of the contact points of differential pinion gear (2) and left and right side gears (1, 3) in the torque proportioning differential. 3. When left side gear (1) rotates slightly more forward than right side gear (3), distance a of the contact point of differential pinion gear (2) and left side gear (1) is longer than distance b of right side gear (3). Correlation of the forces at this time is as follows. a×TA (force applied to left side gear (1)) = b×TB (force applied to right side gear (3)). 4. Until the difference of the road resistances exceeds the certain value, differential pinion gear (2) does not rotate, but left and right side gears (1, 3) rotate at the same speed solidly. 5. Besides, the left tire does not rotate redundantly and does not slip. (The right tire can have drive force larger than the left tire.) 6. Therefore, tire life is prolonged, and working efficiency is improved.

T3-11-7

T487-03-06-017

SECTION 3 COMPONENT OPERATION Group 11 Axle Limited Slip Differential (LSD) A wheel loader, as required by the kind of work, must be operated in places where skidding takes place easily like sand and muddy soil. In places like these, tires can slip even if the torque proportioning differential (TPD) is installed. Rotation is transmitted to the slipping tire, but not to the tires contacting the earth, so not only is the function of the wheel loader worsened, but the tire lives are shortened. To avoid this, a limited slip differential (LSD) (equipped with a differential and axle shaft movement restriction device) can be provided to help avoid loose movement of one side of the axle, and provide more stable tractive conditions. Drive force between the left and right side is more stable.

LSD is so constructed so that clutch disc (5) is inserted between pressure ring (2) supporting spider (8) with the cam and case (6), which increases restriction of different movement and assists to keep the left and right side tire speeds close to the same. In addition, the left to right tractive ratio is better for traction than the TPD style differentials.

4 3

12-

Ring Gear Clutch Assembly

34-

Side Gear Pin

56-

Case Bolt

T3-11-8

TNDF-03-11-003 78-

Pinion Gear Spider

SECTION 3 COMPONENT OPERATION Group 11 Axle Traveling Straight with the Same Road Resistances to Left and Right Tires 1. As the differential pinion gear and the left and right pinion gears rotate together simultaneously, the drive forces of the left and right tires are the same, similar to the TPD.

Traveling on Soft Roads (Different Road Resistances to Left and Right Tires)

3 2

1. Drive force is transmitted to case (5) and the spider through the ring gear. 2. At this time, as the driving force is routed to the pinion gear, component force (P) of the reaction force routed to the pinion gear is routed to side gear (3) and pushes clutch assembly (2) to toward case (5).

3. Clutch assembly (2) is geared with case (5) through side gear (3). 4. Side gears (3) connected to clutch assembly (2) by spline joint rotate solidly with case (5), and left and right side gears (3) rotate at the same speed. 5. Therefore, the left and right axle shafts connected to side gears (3) by spline joint tend to rotate solidly, together with case (5), and the differential movement restriction works, resulting in better overall traction and less tire slippage.

TNDF-03-11-004

23-

6. When the drive force provided for the skidding tire is greater than the road resistance, part of the torque of the skidding tire is added to the tire contacting the road by the differential movement restriction (because of the same rotation speed of the left and right tires), and the tire contacting the road is provided with more torque. 7. Until the difference of the resistances between the left and right tires exceeds the clutch friction gripping value (until clutch assembly (2) begins to slip), the left and right side gears (3) solidly turn together at a constant speed. 8. On such soft roads, the drive force increases by 1.5 times the value for the TPD if the LSD is provided.

T3-11-9

Clutch Assembly Side Gear

Case

SECTION 3 COMPONENT OPERATION Group 11 Axle Service Brake The type of service brake used is a wet-type spring set hydraulic released single-disc brake and is assembled in axle housing (7) of the axle. All four wheels are equipped with wet disc brakes.  When brake is applied 1. Pressure from the brake valve works on the back of brake piston (1) and moves brake piston (1), so that brake friction disc (3) and brake plate (2) are compressed. 2. The inner surface of brake disc (3) is splined to sun gear (6). 3. In addition, the outer surface of brake plate (2) is fixed to differential housing (8). 4. Therefore, the rotation of applied and compressed brake disc (3) stops, slowing the machine.  When brake is released 1. Pressure from the brake valve is reduced, brake piston (1) is returned by steel plate (2). 2. Brake friction plate (3) is released and machine brakes are released.

T3-11-10

SECTION 3 COMPONENT OPERATION Group 11 Axle

8 a

TNDF-03-11-005

When brake is applied

When brake is released 4

TNDF-03-11-006

Brake Pressure Oil

From Brake Valve

To Brake Valve

12-

Brake Piston Steel Plate

34-

Friction Plate Brake Retainer

56-

Axle Shaft Sun Gear

T3-11-11

78-

TNDF-03-11-006

Axle Housing Differential Body

SECTION 3 COMPONENT OPERATION Group 11 Axle Final Drive Planetary / Axle Shaft Final planetary drive (2) is used for gear reduction, to increase of drive output torque to the wheels in the power transmission. The power from the differential is transmitted through sun gear (8) and rotates three planetary gears (4) in internal gear (3). The rotation of planetary gear (4) is transmitted to axle shaft (7) through planetary carrier (5).

3 5

4 TNDF-03-11-007

12-

Axle Shaft Final Drive

34-

Internal Gear Planetary Gear

56-

Planetary Carrier Axle Housing

T3-11-12

78-

Axle Shaft Sun Gear

SECTION 3 COMPONENT OPERATION Group 12 Brake Valve Outline Brake valve (1) supplies brake pressure in proportion to the brake pedal (2) depressing amount to the axle and operates the front and rear service brakes. (Refer to SYSTEM / Hydraulic System.) 1

TNDF-03-12-001

Brake Valve Hydraulic Circuit Diagram

AB-

To Front Axle To Rear Axle

T- To Hydraulic Oil Tank PA- From Brake Charge Valve

PB- From Brake Charge Valve

123-

Brake Valve Brake Pedal Spool

569-

11- Spring 12- Spool 13- Spool

Return Spring Balance Spring Spring

T3-12-1

TNDF-03-12-002

SECTION 3 COMPONENT OPERATION Group 12 Brake Valve Operation Neutral (Output Curve: A to B) 1. When the brake pedal is not depressed, spools (13, 12) are pushed left by springs (9, 11) respectively.

2. Spool (13) pushes balance spring (6) via spring seat (7).

3. Spool (1) is pushed left by balance spring (6) and spring (2) via spring seat (4). 4. Consequently, when the brake pedal is in the neutral position, pressurized oil from port PA and port PB are blocked by spools (13, 12) respectively. Port A and port B are connected to port T (hydraulic oil tank) through the outer circumference of spools (13, 12).

5. When the brake pedal is depressed slightly, spool (1) is pushed and pushes balance spring (6). 6. As pressure at port A and port B are equal to that at port T and the force of balance spring (6) is stronger than the force pushing spools (13, 12) left (the resultant force of springs (9, 11)), spools (13, 12) move right. 7. This status continues until notches (C) on spools (13, 12) are connected to port PA and port PB respectively.

T3-12-2

Pressure in Ports A, B

b T4FC-03-11-003

Piston Stroke

SECTION 3 COMPONENT OPERATION Group 12 Brake Valve

10 11

AB-

To Front Axle To Rear Axle

T- To Hydraulic Oil Tank PA- From Brake Charge Valve

PB- From Brake Charge Valve

1234-

Spool Spring Guide Spring Seat

5678-

9101112-

Return Spring Balance Spring Spring Seat Plunger

T3-12-3

Spring Plunger Spring Spool

13- Spool 14- Brake Pedal

TNDF-03-12-001

SECTION 3 COMPONENT OPERATION Group 12 Brake Valve During Metering or Decompressing (Output Curve: B to C) 1. When the brake pedal is further depressed and spool (1) is pushed, notches (C) on spools (13, 12) are connected to port PA and port PB respectively. Then, pressurized oil in port PA and port PB flow to port A and port B.

2. Pressurized oil in port A and port B are routed to the spool inside through holes (D) of spools (13, 12) and push spools (13, 12) left. a-

3. When the force of balance spring (6) is stronger than the force routed to spools (13, 12) (the force pushing spools (13, 12) left), balance spring (6) is not compressed. Spools (13, 12) do not move and the pressure at port A and Port B keep increasing. 4. When the pressure at port A and Port B increase further, the force pushing spools (13, 12) left increases. When this force overcomes the force of balance spring (6), balance spring (6) is compressed so that spools (13, 12) move left. 5. When spools (13, 12) move left, notches (C) are closed so that pressurized oil from port PA and port PB stop flowing to port A and port B. Then, pressure at port A and Port B stop increasing. 6. Therefore, as balance spring (6) is compressed by the amount as spools (13, 12) are pushed, the pressure balances with the spring force and the force routed to spools (13, 12). This pressure becomes pressure in port A and port B.

T3-12-4

Pressure in Ports A, B

b T4FC-03-11-003

Piston Stroke

SECTION 3 COMPONENT OPERATION Group 12 Brake Valve

10 11

TNDF-03-12-001

T1F3-03-09-006

ABC-

To Front Axle To Rear Axle Notch

D- Hole T- To Hydraulic Oil Tank PA- From Brake Charge Valve

PB- From Brake Charge Valve

1234-

Spool Spring Guide Spring Seat

5678-

9101112-

Return Spring Balance Spring Spring Seat Plunger

T3-12-5

Spring Plunger Spring Spool

T1F3-03-09-005

13- Spool 14- Brake Pedal

SECTION 3 COMPONENT OPERATION Group 12 Brake Valve (Blank)

T3-12-6

SECTION 3 COMPONENT OPERATION Group 13 Ride Control Valve Outline Ride control valve (1) (option) makes the machine travel stable by reducing the force generated in lift arm cylinder (4) when driving on rough. Ride control valve (1) consists of ride control solenoid valve (3), ride control spool (8), charge-cut spool (7), and overload relief valve (9). (Refer to SYSTEM / Hydraulic System.)

11 9

TNDB-03-12-001

T3-13-1

SECTION 3 COMPONENT OPERATION Group 13 Ride Control Valve Ride Control Hydraulic Circuit Diagram

PS2

A1 B1

Pi a

11 9

A B

5 TNDB-03-12-002

A1- Lift Arm Cylinder Bottom Side Circuit B1- Lift Arm Cylinder Rod Side Circuit

aA-

1234-

5678-

Ride Control Valve Ride Control Accumulator Ride Control Solenoid Valve Lift Arm Cylinder

ON Signal from MC Port A (from Lift Arm Cylinder Bottom Side)

B-

Pilot Pump Hydraulic Oil Tank Charge-Cut Spool Ride Control Spool

9- Overload Relief Valve 10- Orifice 11- Drain Plug

Pi-

T3-13-2

Port B (to Lift Arm Cylinder Rod Side) Port Pi (Pilot Pressure Oil)

PS2- Port PS2 (to Ride Control Accumulator) T- Port T (to Hydraulic Oil Tank)

SECTION 3 COMPONENT OPERATION Group 13 Ride Control Valve

PS2

9 b

a A

Section a-a

TNDB-03-12-001

Section b-b

PS2

PS2 A T TNDB-03-12-003

T3-13-3

T T4GD-03-08-001

SECTION 3 COMPONENT OPERATION Group 13 Ride Control Valve Operation 1. When the ride control is not activated, the oil passage between port Pi and output port (2) is blocked by spool (3) in ride control solenoid valve (4). 2. When the conditions for ride control exist, the ON signal from MC excites the solenoid in ride control solenoid valve (4) and spool (3) moves right. 3. Therefore, the oil passage between port Pi and output port (2) is opened. 4. Pilot pressure oil from port Pi flows to output port (2) through spool (3) in ride control solenoid valve (4). 5. When the pressure in output port (2) exceeds the spring (7) force, ride control spool (1) moves right (to the spring (7) side). 6. Therefore, the circuit between port A (the bottom side of lift arm cylinder) and port PS2 (the ride control accumulator) is connected. 7. At the same time, the circuit between port B (the rod side of lift arm cylinder) and port T (hydraulic oil tank) is connected. 8. Consequently, when the force pushing down the lift arm cylinder occurs, the circuit pressure increases and this pressure is reduced by accumulator (6). 9. In addition, the negative pressure in the circuit due to the force pushing down the lift arm is canceled by drawing hydraulic oil supplied from port T.

T3-13-4

SECTION 3 COMPONENT OPERATION Group 13 Ride Control Valve

PS2

3 2 7

A-

123-

Port A (from Lift Arm Cylinder Bottom Side)

Ride Control Spool Output Port Spool

B-

Pi-

Port B (to Lift Arm Cylinder Rod Side) Port Pi (Pilot Pressure Oil)

PS2- Port PS2 (to Ride Control Accumulator) T- Port T (to Hydraulic Oil Tank)

456-

Ride Control Solenoid Valve Pilot Pump Ride Control Accumulator

78-

T3-13-5

Spring Hydraulic Oil Tank

TNDB-03-12-006

SECTION 3 COMPONENT OPERATION Group 13 Ride Control Valve Charge-Cut Spool Charge-cut spool (3) makes the ride control accumulator accumulate pressure oil up to the set pressure. In addition, it keeps the pressure in the ride control accumulator when the ride control accumulator pressure is accumulated to the set pressure. 1. When the ride control is not activated, pressurized oil from the lift arm cylinder bottom side flows to port X through port A and orifice (1). 2. Pressurized oil from port X flows through chargecut spool (3), pushes to open check valve (2), and flows to port Y. 3. Pressurized oil from port Y flows to ride control accumulator and is accumulated. 4. As sectional area M (5) of charge-cut spool (3) is larger than sectional area N (6) and when the ride control accumulator pressure is accumulated to the set pressure, pressurized oil in port X pushes charge-cut spool (3) to the spring (4) side. 5. As charge-cut spool (3) moves to the spring (4) side, the oil passage between port X and port Y is closed. 6. Therefore, pressurized oil is stopped accumulating in the ride control accumulator.

T3-13-6

SECTION 3 COMPONENT OPERATION Group 13 Ride Control Valve When accumulating accumulator pressure 1

PS2

T4GB-03-08-007

After accumulating accumulator pressure

To Ride Control Accumulator

A-

Port A (from Lift Arm Cylinder Bottom Side)

XY-

Port X Port Y

12-

Orifice Check Valve

34-

Charge-Cut Spool Spring

56-

Sectional Area M Sectional Area N

T3-13-7

T4GB-03-08-008

SECTION 3 COMPONENT OPERATION Group 13 Ride Control Valve Overload Relief Valve The overload relief valve prevents the hoses and the ride control accumulator from being damaged in case pressure in the bottom side circuit of the lift arm cylinder is suddenly raised by an external force or something during operation of the lift arm cylinder. Relief Operation 1. Pressure in port HP (actuator circuit) is routed to pilot poppet (8) through orifice A (2) in main poppet (1) and orifice B (3) in seat (4). 2. When pressure in port HP reaches the set force of spring B (6), pilot poppet (8) is opened and pressurized oil flows to port LP (the hydraulic oil tank) through passage A (5) and the periphery of sleeve (11). 3. At this time, a pressure difference is caused between port HP and spring chamber (10) due to orifice A (2). 4. When this pressure difference reaches the set pressure of spring A (9), main poppet (1) is opened and pressurized oil from port HP flows to port LP. 5. Consequently, the actuator circuit pressure decreases. 6. When the actuator circuit pressure decreases to the specified pressure, main poppet (1) is closed by the force of spring A (9).

T3-13-8

SECTION 3 COMPONENT OPERATION Group 13 Ride Control Valve Normal Operation: 12

T176-03-03-012

Relief Operation: 1

HP- Actuator Circuit

LP- Hydraulic Oil Tank

123-

456-

Main Poppet Orifice A Orifice B

Seat Passage A Spring B

8- Pilot Poppet 9- Spring A 10- Spring Chamber

T3-13-9

T176-03-03-013

11- Sleeve 12- Spring C 13- Make-Up Valve

SECTION 3 COMPONENT OPERATION Group 13 Ride Control Valve Make-Up Operation 1. When pressure in port HP (actuator circuit) decreases lower than pressure in port LP (hydraulic oil tank), make-up valve (13) moves left. 2. Hydraulic oil in port LP flows to port HP and cavitation is prevented. 3. When pressure in the port HP side increases to the specified pressure, make-up valve (13) is closed by the force of spring C (12).

T3-13-10

SECTION 3 COMPONENT OPERATION Group 13 Ride Control Valve Make-Up Operation: 12

TNDB-03-12-013

HP- Actuator Circuit

LP- Hydraulic Oil Tank

12- Spring C

13- Make-Up Valve

T3-13-11

SECTION 3 COMPONENT OPERATION Group 13 Ride Control Valve Drain Plug The ride control valve is provided with drain plug (2) in order to return pressure oil of the ride control accumulator to hydraulic oil tank (4) at the time of maintenance or something. Pressurized oil from the ride control accumulator flows to hydraulic oil tank (4) by loosening drain plug (2). Therefore, the pressure of ride control accumulator decreases. Do not loosen drain plug (2) too much dCAUTION: as pressurized oil may spout out due to removal of drain plug (2). Do not loosen drain plug (2) more than 2 turns.

1 2 3

From Ride Control Accumulator

12-

Lock Nut Drain Plug

34-

Overload Relief Valve Hydraulic Oil Tank

T3-13-12

TNDB-03-12-010

SECTION 3 COMPONENT OPERATION Group 14 Others Propeller Shaft Propeller shafts are installed between the transmission and the front axle, and between the transmission and the rear axle, respectively. Propeller shafts transmit the power from the transmission to the front axle and the rear axle. This uses a universal joint (1) and slip joint type spline shaft as shown in the illustration.

2nd Propeller Shaft (Between Front Axle and Transmission) 1

2 2

2 62Z7-03-14-01

3rd Propeller Shaft (Between Transmission and Rear Axle) 1

1 2

T4GB-03-12-004

Universal Joint

Grease Nipple

T3-14-1

SECTION 3 COMPONENT OPERATION Group 14 Others HST Cooler Bypass Check Valve HST (hydrostatic transmission) cooler bypass check valve (1) is provided in the circuit between drain circuits in HST pump and HST motor 1/HST motor 2 and hydraulic oil tank. When abnormal pressure is generated in the circuit, HST cooler bypass check valve (1) is operated and releases abnormal pressure.

a, b, c

TNDF-03-14-001

From HST Pump (Port T1)

HST Cooler Bypass Check Valve

From HST Motor 1 (Port T2)

T3-14-2

From HST Motor 2 (Port T1)

To Hydraulic Oil Tank

SECTION 3 COMPONENT OPERATION Group 14 Others Service Brake Accumulator The service brake accumulator is installed in the accumulation circuit of the brake charge valve. High-pressure nitrogen gas is contained in the accumulator, and pressurized oil from the pilot pump compresses the nitrogen gas through the piston. The brake circuit pressure oil is retained by compression of the nitrogen gas.

TNED-03-07-021

Steering Accumulator The steering accumulator is provided in the circuit between steering valve and steering cylinder. High-pressure nitrogen gas is contained in the accumulator. Pressurized oil compresses the nitrogen gas through the piston. Therefore the shock and the joggling are reduced during steering operation.

TNDF-03-14-002

T3-14-3

SECTION 3 COMPONENT OPERATION Group 14 Others Ride Control Accumulator The ride control accumulator (option) is installed in the accumulation circuit of the ride control. High-pressure nitrogen gas is contained in the accumulator, and pressurized oil compresses the nitrogen gas through the piston. Compression of the nitrogen gas reduces the shock of pressurized oil due to pitching of the lift arm cylinder raise circuit.

TNDB-03-08-009

T3-14-4

SECTION 3 COMPONENT OPERATION Group 14 Others Secondary Steering Check Block (Option) P2

Secondary steering check block (1) is installed between the priority valve and the steering valve. Built-in check valve (4) is provided for preventing from flowing delivery oil (PE) of the secondary steering pump to the priority valve.

S1 PE

TNDF-03-14-012

Section A-A

A P1

TNDB-03-11-003

P1- From Priority Valve PE- From Secondary Steering Pump

S2- Secondary Steering Pump Delivery Pressure Sensor Mounting Port

S1- Steering Pressure Switch Mounting Port Dr- To Hydraulic Oil Tank

34-

Secondary Steering Check Block

Secondary Steering Pump Delivery Pressure Sensor

T3-14-5

Steering Pressure Switch Check Valve

P2- To Steering Valve

SECTION 3 COMPONENT OPERATION Group 14 Others Secondary Steering Pump (Option) The secondary steering pump is started in case supply of the pressurized oil from the main pump is suddenly stopped. The secondary steering pump is installed for supplying pressurized oil to the steering valve in place of the main pump until the time when the vehicle body is moved to a safe place.

The secondary steering pump consists of gear pump (2), electric motor (3), and relief valve (1).

TNED-01-02-019

Relief Valve

Gear Pump

T3-14-6

Electric Motor

SECTION 3 COMPONENT OPERATION Group 14 Others Solenoid Valve Exhaust filter regeneration control solenoid valve (1) is used for the exhaust filter regeneration. Quick coupler pilot solenoid valve (2) and coupler cylinder selector solenoid valve (3) are available as option. Those solenoid valves (2, 3) are used for the quick coupler control.

Exhaust Filter Regeneration Control Solenoid Valve P

It controls the exhaust filter regeneration spool in the control valve according to the signal from MC (main controller). (Refer to SYSTEM / Control System.) Exhaust filter regeneration control solenoid valve (1) is a proportional solenoid valve.

Quick Coupler Pilot Solenoid Valve (Option)

TNDF-03-14-003

It controls the quick coupler spool in the control valve according to the ON/OFF signal from the coupler switch. (Refer to SYSTEM / Hydraulic System.) Quick coupler pilot solenoid valve (2) is an ON/OFF solenoid valve.

Coupler Cylinder Selector Solenoid Valve (Option) It controls the coupler cylinder according to the ON/ OFF signal from the coupler switch. (Refer to SYSTEM / Hydraulic System.) Coupler cylinder selector solenoid valve (3) is an ON/ OFF solenoid valve.

T P

TNDF-03-14-007

B P

TNDF-03-14-006 12-

T3-14-7

Exhaust Filter Regeneration Control Solenoid Valve Quick Coupler Pilot Solenoid Valve (OPT)

Coupler Cylinder Selector Solenoid Valve (OPT)

SECTION 3 COMPONENT OPERATION Group 14 Others Exhaust Filter Regeneration Control Solenoid Valve

 When in neutral 1. Spring (2) pushes spool (1) to the right and output port A is connected to tank port T.

The exhaust filter regeneration control solenoid valve is a proportional solenoid valve, which is controlled by an electric current signal from MC (main controller) and provides output pressure in proportion to the electric current.

 When excited 1. Solenoid (3) pushes spool (1) to the left in proportion to the electrical current flowing through solenoid (3). 2. Pilot pressure oil from port P flows to output port S and pressure at output port S increases. 3. This pressure at output port S is routed to stepped part a of spool (1). Spool (1) is pushed to the right due to surface area differences at the spool surfaces indicated in illustration call out "a". 4. When pressure at output port S increases and the force to push spool (1) to the right overcomes the force to push spool (1) to the left by solenoid (3), spool (1) is moved back to the right and the passage between output port S and port P is closed. Therefore, pressure at output port S stops increasing, and oil flow is stopped.

a TDAA-03-07-013

Spool

Spring

T3-14-8

Solenoid

SECTION 3 COMPONENT OPERATION Group 14 Others Quick Coupler Pilot Solenoid Valve (Option) The quick coupler pilot solenoid valve (option) is an ON/OFF solenoid valve which operates the coupler switch in order to shift pilot pressure.  In Neutral Pilot spool (1) is pushed to the right by spring (2). Output port A is connected to tank port T.  In Operation As solenoid (3) is excited, pilot spool (1) is pushed to the left. Pilot port P is connected to output port A and tank port T is blocked.

Pilot Spool

Spring

TNDF-03-14-008

T3-14-9

Solenoid

SECTION 3 COMPONENT OPERATION Group 14 Others Coupler Cylinder Selector Solenoid Valve (Option) The coupler cylinder selector solenoid valve (option) is an ON/OFF solenoid valve which shifts the flowing direction of pressurized oil between control valve and coupler cylinder by the coupler switch operation.  In Neutral (When locked) 1. Spool (3) is pushed down by the spring (2) force. Output port B is connected to tank port T through spool (3). 2. On the other hand, output port A is closed by poppet (6) in check valve (5). 3. Pressurized oil in port P is routed to poppet (6) in check valve (5) through orifice (4) and spool (3). 4. Therefore, poppet (6) is pushed down and pilot port P is connected to output port A.

1 2

3 4

B P

6 12-

Solenoid Spring

34-

Spool Orifice

TNDF-03-14-010

5 56-

Check Valve Poppet

T3-14-10

Pilot Piston

SECTION 3 COMPONENT OPERATION Group 14 Others  In Operation (When released) 1. As solenoid (1) is excited, spool (3) pushes spring (2) and moves up. 2. Output port B is connected to pilot port P through spool (3). 3. Pressurized oil in output port B is routed to pilot piston (7) in check valve (5) and pushes poppet (6) down. 4. Therefore, returning oil from output port A flows to tank port T through spool (3).

1 2

3 4 B

6 12-

Solenoid Spring

34-

Spool Orifice

TNDF-03-14-011

5 56-

Check Valve Poppet

T3-14-11

Pilot Piston

SECTION 3 COMPONENT OPERATION Group 14 Others Filter The filter is provided in each circuit: pilot filter (1), HST charge oil filter (2), and transmission oil filter (3). A relief valve is built in each filter to protect from abnormal pressure (abnormally high pressure) generated in delivery pressure oil from each pump.

TNDF-04-05-001

3 TNDF-04-05-002

12-

T3-14-12

Pilot Filter HST Charge Oil Filter

Transmission Oil Filter

SECTION 3 COMPONENT OPERATION Group 14 Others Bucket Regenerative Selector Valve

fNOTE: The bucket regenerative selector valve is

The bucket regenerative selector valve shifts the bucket regenerative valve due to the pilot pressure (bucket dump). (Refer to SYSTEM / Hydraulic System.)

equipped for the PL (parallel link) spec. machine.

 When operated 1. Pilot spool (2) is pushed to the right via piston (1) by the pilot pressure from pilot port (a).

 When in neutral 1. Pilot spool (2) is kept in the neutral position via pistons (1, 3) by the spring (4, 5) force. Port B is connected to tank port T.

2. Port P is connected to port B and tank port T is connected to port A so that it is blocked.

2. The pilot pressure is not supplied to the bucket regenerative valve from port B.

3. Pressurized oil from the bucket regenerative valve is supplied to the bucket regenerative valve as the pilot pressure through port P and port B. 4. The bucket regenerative valve is shifted and bucket dump operating speed is increased.

A 5

B-

Port B (To Bucket Regenerative Valve Port Y)

P-

A-

Pilot Port (Pilot Pressure Oil Pib2) Port A (Block)

Port P (Pressurized Oil from Bucket Regenerative Valve Port X)

12-

Piston Pilot Spool

34-

Piston Spring

Spring

T3-14-13

TNDF-03-14-013

T-

Tank Port

SECTION 3 COMPONENT OPERATION Group 14 Others Bucket Regenerative Valve The bucket regenerative valve is provided between the control valve and bucket cylinder. The bucket regenerative valve shifts logic valve (1) due to the pilot pressure from the bucket regenerative selector valve. The bucket regenerative valve combines returning oil from the rod side of bucket cylinder with pressurized oil from the bottom side of bucket cylinder so that bucket dump operating speed is increased. (Refer to SYSTEM / Hydraulic System.)

fNOTE: The bucket regenerative valve is equipped for the PL (parallel link) spec. machine.

X A1

3 A1R B1R

TNDF-03-14-014

A1- Port A1 (Pressurized Oil from Main Pump)

B1- Port B1 (Pressurized Oil from Main Pump)

X-

Port X (To Bucket Regenerative Selector Valve Port P)

Y-

Port Y (From Bucket Regenerative Selector Valve Port B)

12-

Logic Valve Pilot Check Valve

34-

Check Valve Orifice

A1R- Port A1R (Bucket Cylinder Bottom Side)

T3-14-14

B1R- Port B1R (Bucket Cylinder Rod Side)

SECTION 3 COMPONENT OPERATION Group 14 Others Operation:  During Bucket Tilt Operation 1. Pressurized oil from the main pump flows to port B1 through the bucket spool. 2. When the circuit pressure between port B1 and orifice (4) increases due to orifice (4), pressurized oil pushes logic valve (1) to the right and the oil passage is opened. 3. Pressurized oil in port B1 flows to port B1R through logic valve (1) and orifice (4). 4. Pressurized oil in port B1R flows to the rod side of bucket cylinder (5) and tilts the bucket. 5. Returning oil from the bottom side of bucket cylinder (5) flows back to the hydraulic oil tank through port A1R, port A1, and the bucket spool.

TNDF-03-14-015

A1- Port A1 (Pressurized Oil from Main Pump)

B1- Port B1 (Pressurized Oil from Main Pump)

A1R- Port A1R (Bucket Cylinder Bottom Side)

B1R- Port B1R (Bucket Cylinder Rod Side)

12-

34-

Logic Valve Pilot Check Valve

Check Valve Orifice

Bucket Cylinder (2 Used)

T3-14-15

Bucket Regenerative Selector Valve

SECTION 3 COMPONENT OPERATION Group 14 Others  During Bucket Dump Operation 1. Pressurized oil from the main pump flows to the bottom side of bucket cylinder (5) through the bucket spool, port A1, and port A1R, and dumps the bucket.

5. One of pressurized oil in port Y pushes logic valve (1) to the left so that the oil passage is closed. 6. The other of pressurized oil in port Y opens pilot check valve (2).

2. Returning oil from the rod side of bucket cylinder (5) flows back to port B1R.

7. Returning oil from the rod side of bucket cylinder (5) flows through pilot check valve (2) and is combined with pressurized oil from the main pump.

3. Pressurized oil in port B1R is divided by orifice (4) and is supplied to port X and pilot check valve (2).

8. As flow rate of pressurized oil which flows to the bottom side of bucket cylinder (5) increases, bucket dump operating speed is increased.

4. During the bucket dump operation, pressurized oil from port X is routed to port Y through bucket regenerative selector valve (6).

2 3 A1- Port A1 (Pressurized Oil from Main Pump)

B1- Port B1 (Pressurized Oil from Main Pump)

X-

Port X (To Bucket Regenerative Selector Valve Port P)

Y-

Port Y (From Bucket Regenerative Selector Valve Port B)

123-

Logic Valve Pilot Check Valve Check Valve

45-

Orifice Bucket Cylinder (2 Used)

A1R- Port A1R (Bucket Cylinder Bottom Side)

67-

Bucket Regenerative Selector Valve Pilot Pressure Oil

T3-14-16

TNDF-03-14-016

B1R- Port B1R (Bucket Cylinder Rod Side)

INDEX 4-Gear Pump Unit..................................................T1-2-16, T3-1-23 A Accelerator Pedal Control....................................................... T2-2-8 Accessory Circuit.....................................................................T2-5-51 Accessory Circuit (Key Switch: ACC).................................T2-5-10 Alarm Control...........................................................................T2-3-15 Alternator Operation..............................................................T2-5-20 Auto Idling Stop Circuit (Not Used)..................................T2-5-26 Auto Idling Stop Control (Not Used)................................T2-2-76 Auto Regeneration Control, Exhaust Filter.....................T2-2-64 Auto-Warm Up Control.........................................................T2-2-10 Axle, Outline..............................................................................T3-11-1 Axle Shaft................................................................................ T3-11-12 B Brake Charge Valve.................................................. T1-2-18, T3-8-2 Brake Charge Valve, Outline.................................................. T3-8-1 Brake Light Circuit...................................................................T2-5-44 Brake Valve, Hydraulic Circuit Diagram...........................T3-12-1 Brake Valve, Operation..........................................................T3-12-4 Brake Valve, Outline................................................................T3-12-1 Bucket Auto Leveler Control...............................................T2-2-82 Bucket Dump Circuit (Parallel Link Front Attachment) .................................................................................................... T2-4-8 Bucket Regenerative Selector Valve.............................. T3-14-13 Bucket Regenerative Valve................................................ T3-14-14 Bucket Tilt Circuit (Parallel Link Front Attachment)...... T2-4-6 Bypass Function.......................................................................T3-1-20 C Cab Light Circuit......................................................................T2-5-60 CAN Circuit.....................................................................T2-1-2, T2-5-8 Charge Circuit...........................................................................T2-4-46 Charge-Cut Spool....................................................................T3-13-6 Charging Circuit.......................................................................T2-4-24 Charging Circuit (Key Switch: ON).....................................T2-5-18 Clearance Light........................................................................T2-5-30 Clutch Connecting Circuit....................................................T2-4-54 Clutch Control..........................................................................T2-2-38 Clutch Disconnecting Circuit..............................................T2-4-56 Clutch Operation.....................................................................T3-10-8 Clutch Pressure Control Solenoid Valve...... T3-10-5, T3-10-10 Clutch Shaft Part......................................................................T3-10-4 Combined Operation Circuit...............................................T2-4-10 Constant Torque Control......................................................T3-1-12 Control Lever Lock Solenoid Valve...................................... T3-9-8 Control System, Outline.......................................................... T2-2-1 Control Valve.............................................................................T1-2-17 Control by Electric and Hydraulic Combined Circuit ..................................................................................................T2-2-81 Controller, Outline..................................................................... T2-1-1 Coupler Cylinder Selector Solenoid Valve (Option).T3-14-10 Cutoff Valve...............................................................................T3-1-16 D Differential.................................................................................T3-11-2 Differential, Operation...........................................................T3-11-5

Differential, Principle..............................................................T3-11-4 Differential, Purpose...............................................................T3-11-3 Displacement Angle Control Cylinder............................... T3-1-6 Drain Plug................................................................................ T3-13-12 E ECM System, Outline................................................................ T2-3-1 EGR Control...............................................................................T2-3-12 Electric Power Circuit (Key Switch: OFF)............................ T2-5-4 Electrical Component, Specifications..............................T1-3-12 Electrical System (Cab)............................................................ T1-2-7 Electrical System (Overview)................................................. T1-2-6 Electrical System, Outline....................................................... T2-5-1 Energy Saving Control...........................................................T2-2-50 Engine..........................................................................................T1-2-13 Engine, Specifications.............................................................. T1-3-1 Engine Accessories, Specifications...................................... T1-3-5 Engine Control............................................................................ T2-2-4 Engine Performance Curve (4HK1XZWT-01)................... T1-3-4 Engine Protection Control....................................................T2-2-42 Engine Protection Control...................................................... T2-2-6 Engine Stop Circuit.................................................................T2-5-24 Exhaust Filter............................................................T1-2-15, T2-3-16 Exhaust Filter Auto Regeneration Control......................T2-2-64 Exhaust Filter Manual Regeneration Control................T2-2-62 Exhaust Filter Operation.......................................................T2-3-17 Exhaust Filter Regeneration Circuit..................................T3-3-24 Exhaust Filter Regeneration Control Circuit..................T2-4-38 Exhaust Filter Regeneration Control Solenoid Valve ..................................................................................................T3-14-8 Exhaust Filter Regenerative Control.................................T2-3-18 External Pilot Pressure Circuit.............................................T3-3-24 F Fan Circuit..................................................................................T2-4-58 Fan Control, Valve Control....................................................T2-2-55 Fan Motor..................................................................................... T3-4-1 Fan Normal Rotation Control Circuit...............T2-4-60, T2-4-62 Fan Reverse Rotation Control.............................................T2-2-58 Fan Reverse Rotation Control Circuit...............................T2-4-62 Fan Reverse Rotation Idle Speed Limiter........................T2-2-18 Fan Reverse Rotation Operation.......................................... T3-4-8 Fan Speed Control...................................................................T2-2-56 Fan Speed Control Operation............................................... T3-4-4 Fan Valve...................................................................... T1-2-19, T3-4-3 Fan Valve (with Fan Reverse Rotation).............. T1-2-19, T3-4-7 Filter.......................................................................................... T3-14-12 Final Drive Planetary........................................................... T3-11-12 Flow Rate Control Valve........................................................T3-3-18 Flushing Valve...........................................................................T3-2-12 Forward Circuit.........................................................................T2-4-48 Forward/Reverse Control Solenoid Valve ......................T3-1-14 Forward/Reverse Idle Speed Limiter................................T2-2-12 Forward/Reverse Lever Priority Control..........................T2-2-34 Forward/Reverse Selection Control..................................T2-2-30 Front Attachment Operation Circuit................................T2-4-32 Front Console.............................................................................. T1-2-8 62Z7/67Z7/67TM7 F&S

INDEX Front Wiper Circuit..................................................................T2-5-54 Fuel Injection Control.............................................................. T2-3-2 Fuel Injection Pressure Control............................................ T2-3-6 Fuel Injection Rate Control.................................................... T2-3-8 Fuel Injection Timing Control............................................... T2-3-8 Fuel Injection Volume Control.............................................. T2-3-4 Fuel Injection Volume Correction Control......................T2-3-10 H Hazard Light Circuit (Key Switch: OFF)............................T2-5-36 Head Light Circuit..................................................T2-5-30, T2-5-32 High Beam Circuit...................................................................T2-5-34 High-Pressure Relief Valve....................................................T3-1-18 Horn Circuit (Key Switch: OFF)............................................T2-5-40 HST Alarm Control..................................................................T2-2-52 HST Charging Pump...............................................................T3-1-22 HST Circuit..................................................................................T2-4-44 HST Cooler Bypass Check Valve..........................................T3-14-2 HST Motor..................................................................................T1-2-17 HST Motor, Outline................................................................... T3-2-1 HST Motor Layout..................................................................... T3-2-2 HST Pump..................................................................T1-2-16, T2-2-21 HST Pump Layout...................................................................... T3-1-2 Hydraulic Circuit, Control Valve............................................ T3-3-6 Hydraulic Component, Specifications............................... T1-3-7 Hydraulic System, Outline...................................................... T2-4-1 I Inching Circuit..........................................................................T2-4-50 Inching Control........................................................................T2-2-28 L Layout of Multiple Control Valve......................................... T3-3-3 License Light.............................................................................T2-5-30 Lift Arm Auto Leveler Height Kickout Control..............T2-2-72 Lift Arm Auto Leveler Lower Kickout Control................T2-2-74 Lift Arm Float Control...........................................T2-2-84, T3-3-22 Lift Arm Kickout Control.......................................................T2-2-86 Light Bulb Check Circuit (Key Switch: ON)....................... T2-5-6 Limited Slip Differential (LSD).............................................T3-11-8 Load-free Engine High Idle Limiter...................................T2-2-14 Low Brake Oil Pressure Indicator Control.......................T2-2-68 Low Steering Oil Pressure Indicator Control (Option).................................................................................T2-2-70 Low-Pressure Relief Valve.....................................................T3-1-18 LSD................................................................................................T3-11-8 M Main Circuit, Control Valve..................................................... T3-3-6 Main Circuit, Electrical............................................................. T2-5-2 Main Circuit, Hydraulic............................................................ T2-4-2 Main Component Layout (Hydraulic System)................. T1-2-3 Main Component Layout (Overview)................................. T1-2-1 Main Component Layout (Travel System)........................ T1-2-5 Main Relief Valve........................................................................ T3-3-8 Make-Up Operation............................................ T3-4-14, T3-13-10 Make-Up Valve........................................................... T3-3-16, T3-5-8 Manifold Valve........................................................... T1-2-18, T3-9-2

Manifold Valve, Outline........................................................... T3-9-1 Manual Regeneration Control, Exhaust Filter...............T2-2-62 Matching Control....................................................................T2-2-24 Monitor Panel...........................................................................T1-2-12 Motor Control...........................................................................T2-2-21 Motor Displacement Angle Control.................. T2-2-26, T3-2-8 Motor Displacement Angle Control Solenoid Valve..... T3-2-7 Multiple Control Valve............................................................. T3-3-1 Multiple Control Valve, Hydraulic Diagram...................... T3-3-2 Multiple Control Valve, Outline............................................ T3-3-1 N Neutral Circuit...........................................................................T2-4-46 Neutral Circuit, Hydraulic....................................................... T2-4-4 Neutral Engine Start Circuit.................................................T2-5-16 Neutral, Steering Valve............................................................ T3-5-5 O Operation of Fuel Injection.................................................... T2-3-8 Overheat Prevention Control..............................................T2-2-46 Overload Relief Valve.............................T3-3-10, T3-5-6, T3-13-8 Overload Relief Valve for Bucket Dump Circuit............T3-3-10 Overload Relief Valve for Lift Arm Raise and Bucket Roll Back Circuits.................................................T3-3-14 Overrun Prevention Control................................................T2-2-44 P Parallel Link, Bucket Dump Circuit...................................... T2-4-8 Parallel Link, Bucket Tilt Circuit............................................. T2-4-6 Parking Brake......................................................................... T3-10-16 Parking Brake: Applied..........................................................T2-5-48 Parking Brake: Released........................................................T2-5-46 Parking Brake Circuit.............................................T2-4-30, T2-5-46 Parking Brake Solenoid Valve................................................ T3-9-6 Pilot Accumulator ...................................................................T3-9-10 Pilot Circuit................................................................................T2-4-22 Pilot Operation Control Circuit...........................................T3-3-20 Pilot Reducing Valve................................................................. T3-9-4 Pilot Valve (Auxiliary) (Option), Operation....T3-7-18, T3-7-24 Pilot Valve (Auxiliary) (Option), Outline..........T3-7-17, T3-7-23 Pilot Valve (Fingertip Control Type Pilot Valve), Electromagnetic Detent..................................................T3-7-16 Operation..............................................................................T3-7-12 Outline...................................................................................T3-7-11 Pilot Valve (Joystick Type Pilot Valve), Electromagnetic Detent..................................................T3-7-10 Operation................................................................................ T3-7-2 Outline..................................................................................... T3-7-1 Power Transmission................................................................T3-10-6 Power Transmission (At Fast Speed).................................T3-10-7 Power Transmission (At Slow Speed)...............................T3-10-6 Preheating Control..................................................................T2-3-14 Priority Valve Circuit...............................................................T2-4-14 Priority Valve, Operation......................................................... T3-6-4 Priority Valve, Outline.............................................................. T3-6-1 Priority Valve, Structure........................................................... T3-6-2 62Z7/67Z7/67TM7 F&S

INDEX Propeller Shaft..........................................................................T3-14-1 Proportional Solenoid Valve............................................. T3-10-14 Pump Circuit Diagram............................................................. T3-1-3 Pump Device, Outline.............................................................. T3-1-1 Pump Displacement Angle Control Solenoid Valve...T3-1-10 Pump Power Control..............................................................T2-2-22 Q Quick Coupler Circuit (Option)..........................T2-4-40, T3-3-26 Quick Coupler Pilot Solenoid Valve (Option).................T3-14-9 R Rear Console.............................................................................T1-2-11 Rear Wiper Circuit....................................................................T2-5-56 Recovery Moment Function.................................................. T3-1-8 Regulator...................................................................................... T3-2-6 Regulator, Transmission..................................................... T3-10-12 Regulator Operation..............................................................T2-5-21 Reverse Buzzer Circuit...........................................................T2-5-42 Reverse Circuit..........................................................................T2-4-48 Reverse-Acceleration Prevention Control at Forward/Reverse Selection............................................T2-2-32 Ride Control (Option).............................................................T2-2-60 Ride Control Accumulator (Option)..................................T3-14-4 Ride Control Circuit (Option)...............................................T2-4-34 Ride Control Hydraulic Circuit Diagram..........................T3-13-2 Ride Control Valve (Option).................................................T1-2-20 Ride Control Valve, Operation.............................................T3-13-4 Ride Control Valve, Outline..................................................T3-13-1 Right Console.............................................................................. T1-2-9 Rotary Group.................................................................T3-1-4, T3-2-4

Steering Stop Circuit..............................................................T2-4-18 Steering Valve, Operation....................................................... T3-5-3 Steering Valve, Outline............................................................ T3-5-1 Steering Valve, Structure........................................................ T3-5-2 Surge Voltage Prevention Circuit.......................................T2-5-22 T Tail Light Circuit.......................................................................T2-5-30 Torque Proportioning Differential (TPD).........................T3-11-6 TPD...............................................................................................T3-11-6 Transmission.............................................................................T1-2-17 Transmission, Layout..............................................................T3-10-3 Transmission, Outline............................................................T3-10-1 Transmission Circuit...............................................................T2-4-52 Transmission Hydraulic Circuit Diagram.........................T3-10-2 Transmission Lubrication Circuit.......................................T2-4-56 Turn Signal Light Circuit:.......................................................T2-5-38 V Variable Turbocharger Control...........................................T2-3-20 W Washer Circuit...........................................................................T2-5-58 Wiper Circuit..............................................................................T2-5-54 Work Light Circuit....................................................................T2-5-52

S Safety Park Control (On Slope)...........................................T2-2-48 Secondary Steering Block (Option)...................................T1-2-21 Secondary Steering Check Block (Option).....................T3-14-5 Secondary Steering Circuit (Option)................................T2-4-20 Secondary Steering Control (Option)..............................T2-2-78 Secondary Steering Pump (Option)................T1-2-21, T3-14-6 Service Brake.......................................................................... T3-11-10 Service Brake Accumulator .................................................T3-14-3 Service Brake Circuit...............................................................T2-4-28 Slow Return Valve....................................................................T3-3-20 Solenoid Valve..........................................................................T3-14-7 Solenoid Valve (In Front Chassis).......................................T1-2-22 Specifications (62Z7/67Z7).................................................... T1-1-1 Specifications (67TM7)............................................................ T1-1-2 Speed Limit Control................................................................T2-2-40 Speed Limit Control with Power Mode OFF..................T2-2-16 Speed Shift Control.................................................................T2-2-36 Starter Relay 1 Operation.....................................................T2-5-14 Starting Circuit (Key Switch: START).................................T2-5-12 Steering (Left)............................................................................. T3-5-4 Steering (Right).......................................................................... T3-5-5 Steering Accumulator............................................................T3-14-3 Steering Circuit........................................................T2-4-12, T2-4-16 Steering Column Monitor Circuit......................................T2-5-29 62Z7/67Z7/67TM7 F&S

INDEX (Blank)

62Z7/67Z7/67TM7 F&S