DOWNLOAD PDF KCM 70Z7B Wheel Loader CUMMINS QSB6.7 Engine SHOP MANUAL PN 93208-00850 by www.heydownloads.com

70Z7B

93208-00850 November 2016

SHOP MANUAL

General Information Function & Structure

WHEEL LOADER

70Z7B General Information Function & Structure

Printed in Japan (K) （アメリカ用）

93208-00850

SECTION AND GROUP SECTION 1 GENERAL Group 1 Specifications CONTENTS Group 2 Component Layout Group 3 Component Specifications

SECTION 2 SYSTEM SHOP MANUAL (Function & Structure)

Group 1 Controller Group 2 Control System Group 3 Engine System Group 4 Hydraulic System Group 5 Electrical System

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Group 2 Control Valve Group 3 Cooling Fan System Group 4 Steering Pilot Valve Group 5 Priority Valve Group 6 Pilot Valve Group 7 Brake Charge Valve/Manifold Valve Group 8 Drive Unit Group 9 Axle Group 10 Brake Valve 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.

Group 11 Ride Control Valve Group 12 Others

(Blank)

SECTION 1

GENERAL CONTENTS Group 1 Specifications Specifications ....................................................................... T1-1-1

Group 2 Component Layout Main Component (Overview) ......................................... T1-2-1 Main Component ................................................................ T1-2-3 Electrical System (Overview) .......................................... T1-2-5 Air Cleaner and Radiator Assembly .............................. T1-2-6 Battery Box ............................................................................ T1-2-8 Hydraulic Tank ...................................................................... T1-2-9 Fuel Tank ..............................................................................T1-2-10 Drive Unit .............................................................................T1-2-11 Front Axle.............................................................................T1-2-12 Cab .........................................................................................T1-2-13 Engine ...................................................................................T1-2-19 Aftertreatment Device ....................................................T1-2-20 Fan Valve (Option).............................................................T1-2-21 Priority Valve .......................................................................T1-2-21 Pump Device ......................................................................T1-2-22 Control Valve.......................................................................T1-2-22 Manifold Valve....................................................................T1-2-23 Parking Brake Solenoid Valve Block ...........................T1-2-23 Brake Charge Valve (Unloader Valve) .........................T1-2-23 Ride Control Valve (Option) ...........................................T1-2-24 Secondary Steering Block (Option) ............................T1-2-25 Secondary Steering Pump (Option) ...........................T1-2-25 Flow Regulator Valve .......................................................T1-2-25 DEF Tank ...............................................................................T1-2-26 DEF Supply Module..........................................................T1-2-26

Group 3 Component Specifications Engine ..................................................................................... T1-3-1 Engine Accessories ............................................................. T1-3-5 Hydraulic Component ....................................................... T1-3-6 Electrical Component ......................................................T1-3-11

70Z7B F&S (US)

(Blank)

70Z7B F&S (US)

SECTION 1 GENERAL Group 1 Specifications Specifications

45 ° E

40 °

F D R1 A R2

MPD8-12-001

Model Bucket Capacity: heaped Operating Weight Tipping Load Engine A: Overall Length B: Overall Width (Bucket) C: Overall Height D: Wheel Base E: Tread (front and rear tires) 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 (at Power mode) Transmission Speeds (F/R) Articulation Angle (Left/Right) deg Tire Size

m3 (Y3) kg (lbs) kg (lbs) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in)

70Z7B 2.8 (3.7) 14560 (32100) 10440 (23020) CUMMINS QSB6.7 8000 (315) 2730 (107) 3280 (129) 3100 (122) 2050 (81) 395 (16) 3920 (155) 2760 (109) 1110 (44) 5580 (220) 6230 (245) 38.5 (23.9)/26.5 (16.5) (38.5 (23.9)/28.3 (17.6)) 5/3 40 20.5-25-12PR (L2)

km/h (mph) (°) -

fNOTE: These specifications are subject to change without notice.

T1-1-1

SECTION 1 GENERAL Group 1 Specifications (Blank)

T1-1-2

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

7 6 5 4 3 2

10 11

TNEK-01-02-007

1234-

Bucket Bucket Link Bell Crank (Lever) Bucket Cylinder

Front Combination Light (Headlight, Turn Signal Light, Clearance Light, Hazard Light) (2 Used)

6789-

T1-2-1

Horn (2 Used) Front Work Light (2 Used) Cab (Refer to T1-2-13.) DEF Tank Box

10- Lift Arm Cylinder (2 Used) 11- Lift Arm

SECTION 1 GENERAL Group 2 Component Layout

TNEK-01-02-008

12- Rear Work Light (2 Used)

13- Rain Cap/Pre-Cleaner (Option)

14- Battery Box (Refer to T1-2-8.)

T1-2-2

15- Rear Combination Light (Turn Signal Light, Hazard Light, Tail Light, Brake Light) (2 Used)

SECTION 1 GENERAL Group 2 Component Layout Main Component

15 14 17

13 12 11 10 9 TPD8-01-02-001

1234-

Air Cleaner and Radiator Assembly (Refer to T1-2-6.) Aftertreatment Device (Refer to T1-2-20.) Hydraulic Tank (Refer to T12-9.) Parking Brake Solenoid Valve (Refer to T1-2-23.)

56789-

Manifold Valve (Refer to T12-23.) Brake Valve Steering Pilot Valve Multiple Control Valve (Refer to T1-2-22.) Ride Control Valve (Refer to T1-2-24.)

10- Ride Control Accumulator (Option) 11- Brake Charge Valve (Unloader Valve) (Refer to T1-2-23.) 12- Pilot Filter 13- Service Brake Accumulator (2 Used)

T1-2-3

14- Flow Regulator Valve (Refer to T1-2-25.) 15- Pilot Valve 16- Engine (Refer to T1-2-19.) 17- Priority Valve

SECTION 1 GENERAL Group 2 Component Layout

23 31 24

30 29

25 TPD8-01-02-002

17- Front Axle (Refer to T1-2-12.) 19- Steering Accumulator (2 Used) 21- Pump Device (Refer to T1-222.)

22232425-

Drive Unit (Refer to T1-2-11.) Fuel Prefilter Fuel Tank (Refer to T1-2-10.) DEF Supply Module

26- DEF Tank 27- Torque Converter Cooler Check Valve 28- Rear Axle

T1-2-4

29- Third (Rear) Propeller Shaft 30- Second (Front) Propeller Shaft 31- Steering Cylinder (2 Used)

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

10 9

8 6

7 TNEK-01-02-003

123-

Engine (Refer to T1-2-19.) Hydraulic Tank (Refer to T12-9.) Cab (Refer to T1-2-13.)

4567-

Bucket Proximity Switch Lift Arm Proximity Switch Battery Box (Refer to T1-2-8.) Fuel Tank (Refer to T1-2-10.)

8- DEF Tank (Refer to T1-2-25.) 9- Backup Alarm 10- DEF Supply Module (Refer to T1-2-25.)

T1-2-5

SECTION 1 GENERAL Group 2 Component Layout Air Cleaner and Radiator Assembly

View A

5 5 6

1 8

7 4

12-

Air Cleaner Radiator Assembly (Refer to T1-2-7.)

34-

TNEK-01-02-011

Fan Valve (Refer to T1-2-21.) Intercooler Outlet Temperature Sensor

TNEK-01-02-012

567-

T1-2-6

Reserve Tank Air Filter Restriction Switch TBAP Sensor

Coolant Level Sensor

SECTION 1 GENERAL Group 2 Component Layout Radiator Assembly

View A

a TNEK-01-02-010

TNEK-01-02-009

Machine Front Side

12-

Reserve Tank Radiator

34-

Oil Cooler Intercooler

56-

T1-2-7

Torque Converter Cooler Fan Motor

SECTION 1 GENERAL Group 2 Component Layout Battery Box 1

Detail A

2 A

6 7

3 9

10 2 11 MNEK-01-015

123-

Battery Box Battery (2 Used) Battery Disconnect Switch

456-

Battery Relay Fusible Link (70 A) Fusible Link (140 A)

789-

T1-2-8

Fusible Link (65 A) Fusible Link (45 A) Fusible Link (65 A)

TNEK-01-02-004

10- Starter Relay 11- Intake Air Heater Relay

SECTION 1 GENERAL Group 2 Component Layout Hydraulic Tank

a 5

4 TNEG-01-02-014

Machine Front Side

12-

Hydraulic Tank Hydraulic Oil Level Sensor

Washer Fluid Tank

T1-2-9

Hydraulic Oil Temperature Sensor

Secondary Steering Pump (Option) (Refer to T1-2-25.)

SECTION 1 GENERAL Group 2 Component Layout Fuel Tank

TNEK-01-02-013

Machine Front Side

12-

Fuel Tank Fuel Level Sensor

34-

Fuel Pump Water Separator Sensor

T1-2-10

Fuel Prefilter

SECTION 1 GENERAL Group 2 Component Layout Drive Unit

7 2

8 A

5 3 4

TNEK-01-02-014

TNEK-01-02-015

View A

TNEK-01-02-016

Machine Front Side

Transmission Intermediate Shaft Sensor Torque Converter Output Speed Sensor Transmission Oil Filter Machine Speed Sensor Transmission Oil Filter Restriction Switch

2345-

6789-

Torque Converter Input Speed Sensor Breather Torque Converter Oil Temperature Sensor Transmission Control Valve

10- Proportional Solenoid Valve Y1 (For Fast-Speed Forward Clutch) 11- Proportional Solenoid Valve Y2 (For Reverse Clutch) 12- Proportional Solenoid Valve Y3 (For 1st Speed Clutch)

T1-2-11

13- Proportional Solenoid Valve Y4 (For 3rd Speed Clutch) 14- Proportional Solenoid Valve Y5 (For Slow-Speed Forward Clutch) 15- Proportional Solenoid Valve Y6 (For 2nd Speed Clutch)

SECTION 1 GENERAL Group 2 Component Layout Front Axle

2 TNEE-01-02-018

Pressure Sensor (Brake Secondary Pressure)

Axle Oil Temperature Sensor

T1-2-12

SECTION 1 GENERAL Group 2 Component Layout Cab

Detail D

a 4

TNEK-01-02-017

D View F

e 7

c TNEG-01-02-002

TNEG-01-02-041

Front Console (Refer to T1-214.)

Right Console (Refer to T1-215.)

1234-

Radio Upper Switch Panel (Option) Speaker (2 Used) Rear Wiper Motor

5678-

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

9- Front Wiper (1) Relay 10- Front Wiper (2) Relay 11- GPS Antenna (Option)

T1-2-13

Rear Console (Refer to T1-216.)

Control Unit (Refer to T1-2-17.)

12- Communication Terminal Antenna

SECTION 1 GENERAL Group 2 Component Layout Front Console 1 2

MNEC-01-036

12 13 14 11 10

15 MNEC-01-037

12345-

Hazard Light Switch Work Light Switch Parking Brake Switch Neutral Lever Lock for Forward/Reverse Lever Steering Wheel

6789-

Monitor Panel (Refer to T12-18.) Horn Accelerator Pedal Brake/ Declutch Pedal (Both at left and right are interlocked.)

MNEC-01-038

10- Front/Rear Wiper Switch 11- Forward/Reverse Lever/Shift Switch 12- Turn Signal Lever/Light Switch/Dimmer Switch 13- Key Switch

T1-2-14

14- Multi-Function Monitor/Air Conditioner Control Panel 15- Cigar Lighter

SECTION 1 GENERAL Group 2 Component Layout Right Console

Fingertip Control Lever Type 4

19 5

3*(1)

6 7 8

9 10

2*(3)

11 12 20

1*(2)

21 18

13 14 15 MNEC-01-042

MNEC-01-041

Multi-Function Joystick Lever Type 21

6 7 8

2210 11

24 23

12 25 26

1*- Auxiliary Control Lever (Option) 2*- Bucket Control Lever 3*- Lift Arm Control Lever 4- Forward/Reverse Switch 5- Control Lever Lock Switch 6- Declutch Position Switch 7- Travel Mode Switch

13 14 15 MNEC-01-044 MNEC-01-043

89-

Power Mode Switch Forward/Reverse Selector Switch 10- Fan Reversing Switch 11- Auxiliary 12- Hydraulic Coupler Switch (Option)

13- Secondary Steering Check Switch (Option) 14- Manual Regeneration Switch 15- Auxiliary 16- First Speed Fixed Switch 17- Ride Control Switch (Option) 18- Hold Switch 19- DSS (Down Shift Switch)

fNOTE: * The layout of each control lever may depend on the machine specification.

T1-2-15

20- Horn Switch 21- Quick Power Switch 22- Forward/Reverse Selector Switch 23- Forward/Reverse Switch 24- Multi-Function Joystick Lever 25- Hold Switch (Under the Lever) 26- Horn Switch (Under the Lever)

SECTION 1 GENERAL Group 2 Component Layout Rear Console

8 7 6 5

14 13 12 11 10

19 18 17 16 15 24 23 22 21 20

29 28 27 26 25 34 33 32 31 30

TNEK-01-02-018

1234567891011-

Fuse Box B Fuse Box A MPDr. Connector ECM Main Relay Starter Cut Relay (C-R1) Fuel Pump Relay (C-R2) DEF Heater Relay 1 (C-R3) DEF Heater Relay 2 (C-R4) DEF Heater Relay 3 (C-R5) Supply Module Relay (C-R6) DEF Sensor Relay (C-R7)

12- Parking Brake Light Relay (C-R8) 13- ECM Timer Relay (C-R9) 14- Not Used 15- Headlight Relay (Left) (A-R1) 16- Headlight Relay (Right) (A-R2) 17- High Beam Relay (A-R3) 18- Bucket Leveler Relay (A-R4) 19- Back Buzzer Relay (A-R5) 20- Work Light (Front) Relay (A-R6) 21- Work Light (Rear) Relay (A-R7)

22- Right Turn Signal Light Relay (A-R8) 23- Horn Relay (A-R9) 24- Secondary Steering Relay (A-R10) 25- Parking Brake Relay 1 (B-R1) 26- Parking Brake Relay 2 (B-R2) 27- Control Lever Lock Relay (B-R3) 28- Brake Light Relay (B-R4) 29- Load Dump Relay (B-R5) 30- Neutral Relay (B-R6)

T1-2-16

31- Left Turn Signal Light Relay (B-R7) 32- Front Washer Relay (B-R8) 33- Rear Wiper Relay (B-R9) 34- Rear Washer Relay (B-R10) 35- Relay Box C 36- Relay Box A 37- Relay Box B 38- Engine Data Link Connector

SECTION 1 GENERAL Group 2 Component Layout Control Unit b

TNEG-01-02-004

TNED-01-02-029

3 6

a 2

TNEK-01-02-020

TNEK-01-02-019

Machine Front Side

Monitor

Monitor Controller

TCU (Transmission Control Unit)

34-

T1-2-17

MC (Main Controller) GSM/GPS (Option)

56-

Flasher Relay Air Conditioner Controller

SECTION 1 GENERAL Group 2 Component Layout Monitor Panel

7 8 9

11 16

12 13

12345-

Left Turn Signal Light Indicator High Beam Indicator Work Light Indicator Right Turn Signal Light Indicator Parking Brake Indicator

6789-

Brake Oil Low Pressure Indicator Hydraulic Oil Level Indicator Low Steering Oil Pressure Indicator (Option) Transmission Warning Indicator

101112131415-

T1-2-18

Control Lever Lock Indicator Fuel Level Indicator Alternator Indicator Fuel Gauge Multi-Function Monitor Communication System Error Indicator

MNEC-01-001

16171819202122-

Coolant Temperature Gauge Overheat Indicator Engine Warning Indicator Engine Oil Pressure Indicator Preheat Indicator Air Filter Restriction Indicator Clearance Light Indicator

SECTION 1 GENERAL Group 2 Component Layout Engine 2

10 11 13

TNEE-01-02-010

12 15

TNEE-01-02-011

12345-

Coolant Temperature Sensor EGR Gas Differential Pressure Sensor EGR Gas Temperature Sensor EGR Valve Crankcase Pressure Sensor

Boost Pressure/Boost Temperature Sensor 7- Common Rail Pressure Sensor 8- Fan Pump 9- Supply Pump 10- Fuel Main Filter

111213141516-

T1-2-19

ECM Crank Revolution Sensor Cam Angle Sensor Engine Oil Pressure Switch EGR Motor Position Sensor Turbocharger Speed Sensor

17181920-

Exhaust Pressure Sensor Alternator Engine Oil Filter Starter Motor

SECTION 1 GENERAL Group 2 Component Layout Aftertreatment Device

2 3 4

5 6

11 10 1 7

8 9

Machine Front Side

12-

Aftertreatment Device SCR Inlet Exhaust Temperature Sensor SCR Catalyst

456-

TNEK-02-03-001

Diesel Oxidation Catalyst (DOC) 2 SCR Outlet Exhaust Temperature Sensor NOx Sensor (SCR Outlet)

789-

T1-2-20

DOC Outlet Exhaust Temperature Sensor Diesel Oxidation Catalyst (DOC) 1 NOx Sensor (SCR Inlet)

10- DOC Inlet Exhaust Temperature Sensor 11- Dosing Module

SECTION 1 GENERAL Group 2 Component Layout Fan Valve (Option)

1 5

3 a TNEE-01-02-031

Priority Valve

6 a

TNDB-01-02-033

Machine Front Side

Fan Speed Control Solenoid Valve

23-

Fan Reverse Rotation Control Solenoid Valve Fan Control Valve

45-

T1-2-21

Fan Reverse Rotation Spool Fan Pump Delivery Pressure Sensor

Main Relief Valve (Steering)

SECTION 1 GENERAL Group 2 Component Layout Pump Device 1

2 a

TNDB-01-02-009

5 a-

Machine Front Side

1245-

Main Pump Regulator Pump Delivery Pressure Sensor Pilot Pump

Control Valve

11 10 7 a

9 T4GB-01-02-027

78-

Overload Relief Valve (Lift Arm: Bottom Side) Overload Relief Valve (Bucket: Bottom Side)

Overload Relief Valve (Bucket: Rod Side) 10- Make-Up Valve (Lift Arm: Rod Side)

11- Main Relief Valve (Front Attachment)

T1-2-22

SECTION 1 GENERAL Group 2 Component Layout Manifold Valve 2

Brake Charge Valve (Unloader Valve) 3

5 6

TNDB-01-02-013

23-

Torque Control Solenoid Valve Control Lever Lock Solenoid Valve

45-

Pressure Sensor (Primary Pilot Pressure) Pilot Accumulator (Front Attachment)

TNED-01-02-021

67-

Parking Brake Solenoid Valve Block

TNEE-01-02-013

89-

Parking Brake Solenoid Valve Pressure Sensor (Parking Brake) 10- Parking Brake Accumulator

T1-2-23

Pressure Sensor (Brake Primary Pressure) Priority Valve

SECTION 1 GENERAL Group 2 Component Layout Ride Control Valve (Option)

TNDB-01-02-040

Front Side of Machine

Front Frame

12-

Overload Relief Valve Ride Control Valve

34-

Ride Control Solenoid Valve Ride Control Accumulator

T1-2-24

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

Flow Regulator Valve

10 4

Secondary Steering Pump Delivery Pressure Sensor (Option)

56-

TNDB-01-02-014

TNDB-01-02-022

Secondary Steering Pilot Valve (Option) Steering Pressure Switch (Option)

10- Pressure Sensor (Life Arm Raise)

Secondary Steering Pump (Option) 9

TNED-01-02-019

Front Side of Machine

789-

Electric Motor Gear Pump Relief Valve

T1-2-25

SECTION 1 GENERAL Group 2 Component Layout DEF Tank 1

10 12 5

TNEK-01-02-021

11 TNEK-01-02-005

1234-

DEF Sensor Unit DEF Tank DEF Quality Sensor DEF Temperature Sensor

567-

DEF Level Sensor DEF Pipe from DEF Supply Module Coolant Pipe to Engine

DEF Pipe to DEF Supply Module Coolant Pipe from Coolant Control Valve

10- Coolant Heater Tube 11- DEF Suction Filter 12- DEF Suction Tube

DEF Supply Module 1

3 TNEK-01-02-006

4 TNEK-01-02-022

12-

DEF Hose (3 Used) DEF Supply Module

35-

Filter Cap Corrugate Tube

67-

T1-2-26

DEF Tube Heating Wire

89-

Thermoplastic Cover Quick Connector (2 Used)

SECTION 1 GENERAL Group 3 Component Specifications Engine Manufacturer

Cummins Inc

Model

QSB6.7

Type

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

Cyl. No.- Bore × Stroke

6-107 mm×124 mm (6-4.21 in×4.88 in)

Piston Displacement

6690 cm3 (408 in3)

Rated Output

129 kW/2200 min-1 (175 PS/2200 rpm)

Dry Weight

580 kg (1280 lb)

Firing Order

1-5-3-6-2-4

Rotation Direction

Clockwise (Viewed from fan side)

T1-3-1

SECTION 1 GENERAL Group 3 Component Specifications COOLING SYSTEM

Cooling Fan

Dia. 850 mm (33.5 in), 6 Blades, Hybrid

Thermostat

Cracking Temperature at Atmospheric Pressure : 88 ºC (190 ºF) Full Open 97 ºC (206 ºF)

LUBRICATION SYSTEM

Lubrication Pump Type

Gear Pump

Oil Filter

Strata Pore (Plastic fiber)/Spin-on Type

Oil Cooler

Water Cooled Type

Motor

Magnetic Pinion Shift Reduction Type

Voltage/Output

24 V/7.8 kW

PREHEAT SYSTEM

Preheating Method

Grid Air Heater (24 V, 100 A)

ENGINE STOP SYSTEM

Stop Method

Fuel Shut-Off (Electronic Control)

ALTERNATOR

Type

AC Type

STARTING SYSTEM

Voltage/Output

24 V/65 A

SUPERCHARGING SYSTEM

Type

Exhaust-Turbocharger Type, Forced Lubrication

FUEL SYSTEM

Type

Common Rail Type HPCR Type

Governor

Electronic All Speed Control

Injection Nozzle

Electrical Multi-Hole Injector

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

220 g/kW/h (162 g/PS·h) (at Full Load : 2200 min-1)

Maximum Output Torque

841 N·m (86 kgf-m, 620 lbf·ft) at 1500 min-1

No Load Speed

Slow : 800±20 min-1 Fast : 2330±30 min-1

T1-3-3

SECTION 1 GENERAL Group 3 Component Specifications Engine Performance Curve (QSB6.7) 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.

900

250

N･m

240 230 800

220 210 200

700

190 180 170

600

160 150 140 P

500

130 T 120 400

110 100 90

300

80 70 60

200

50 40 30

100

20 10 0 800

1000

1200

1400

1600 N

1800

2000

2200

0 2400 min-1

TPD850-01-03-001

P : Output T : Torque

N : Engine Speed

T1-3-4

SECTION 1 GENERAL Group 3 Component Specifications Engine Accessories RADIATOR ASSEMBLY

Type

Radiator, Oil Cooler and Intercooler Parallel Type Assembly, Torque Converter Cooler Tandem Type Assembly

Radiator Air-Tight Test Pressure

Oil Cooler 2

0.1 MPa (1.02 kgf/cm , 14.5 psi)

1.5 MPa (15 kgf/cm2, 218 psi)

Intercooler

Torque Converter Cooler

Air-Tight Test Pressure

0.25 MPa (2.50 kgf/cm , 35.5 psi)

1.5 MPa (15 kgf/cm2, 218 psi)

RESERVE TANK

Total Capacity

8.4 L (2.2 US gal)

Cap Opening Pressure

90 kPa (0.9 kgf/cm2, 13 psi)

Type

160F51

Voltage

12 V

Capacity

108 Ah (5-Hour Rate)

BATTERY

120 Ah (20-Hour Rate) BATTERY (LARGE CAPACITY)

Cold Cranking Capacity

760 A

Type

190 H52

Voltage

12 V

Capacity

120 Ah (5-Hour Rate) 155 Ah (20-Hour Rate)

Cold Cranking Capacity

900 A

T1-3-5

SECTION 1 GENERAL Group 3 Component Specifications Hydraulic Component PUMP DEVICE

Drive Gear Ratio

Main Pump: 1, Pilot Pump: 1

MAIN PUMP

Type

Variable Displacement Swash Plate Axial Plunger Pump

Theoretical Displacement

95 cm3/rev (5.8 in3/rev)

Rated Pressure

27.4 MPa (280 kgf/cm2, 3975 psi)

REGULATOR

Type

Hydraulic Pressure Operated Type

PILOT PUMP

Type

Fixed Displacement Type Gear Pump

Theoretical Displacement

16.8 cm3/rev (1.0 in3/rev)

PRIORITY VALVE

Relief Set-Pressure

25.4 MPa (259 kgf/cm2, 3684 psi) at 240 L/min (63.4 US gpm)

MULTIPLE CONTROL VALVE

Type

Pilot Pressure Operated Type (2-Spools)

Main Relief Set-Pressure

27.4 MPa (280 kgf/cm2, 3975 psi) at 150 L/min (39.6 US gpm)

Overload Relief Set-Pressure

34.3 MPa (350 kgf/cm2, 4975 psi) at 35 L/min (9.2 US gpm) (Lift Arm Raise) 30.4 MPa (310 kgf/cm2, 4410 psi) at 35 L/min (9.2 US gpm) (Bucket)

FRONT ATTACHMENT PILOT VALVE

Auxiliary Pilot Valve (Option) Auxiliary Pilot Valve (Option)

Low-Pressure Relief Valve Set 0.2 MPa (2.0 kgf/cm2, 29 psi) Pressure Type Two Direction Lever Type, 4-Port (With Electromagnetic Detent) Plunger Stroke Ports 1, 2, 3, 4 : 5.7 mm (0.22 in) Type Joystick Lever Type, 4-Port (With Electromagnetic Detent) Plunger Stroke Ports 1, 2, 3, 4 : 10 mm (0.4 in) Type Two Direction Lever Type, 2-Port (Without Detent) Plunger Stroke Ports 1, 2 : 4.8 mm (0.19 in) Type Joystick Lever Type, 4-Port (Without Detent) Plunger Stroke Ports 1, 3 : 6.5 mm (0.26 in) Ports 2, 4 : 8.0 mm (0.32 in)

T1-3-6

SECTION 1 GENERAL Group 3 Component Specifications STEERING PILOT VALVE

Type

Orbitrol ® Type

Over Load Relief SetPressure

29.6 MPa (302 kgf/cm2, 4295 psi) at 3.8 L/min (1 US gpm)

Gerotor Capacity

588 cm3/rev (36 in3/rev)

STEERING ACCUMULATOR

Capacity

0.2 L (12 in3)

Charging Pressure

2.0 MPa (20 kgf/cm2, 290 psi)

BRAKE VALVE

Brake Pressure

5.0 MPa (51 kgf/cm2, 725 psi)

CHARGING VALVE

Charging Pressure

Cut In Pressure : 11.8 MPa (120 kgf/cm2, 1710 psi) Cut Out Pressure : 15.5 MPa (158 kgf/cm2, 2250 psi)

MANIFOLD VALVE

Function

Main Pump Torque Control, Front Control Lever Lock

Pilot Relief Valve SetPressure

3.7 MPa (37.7 kgf/cm2, 537 psi) at 40 L/min (10.6 US gpm)

SERVICE BRAKE ACCUMULATOR

Capacity

1.4 L (85.4 in3)

Charging Pressure

6.8 MPa (69.3 kgf/cm2, 986 psi) at 20 °C (68 °F)

PILOT ACCUMULATOR

Capacity

0.5 L (30.5 in3)

Charging Pressure

1.6 MPa (16 kgf/cm2, 228 psi) at 20 °C (68 °F)

Capacity

0.5 L (30.5 in3)

Charging Pressure

5.9 MPa (60 kgf/cm2, 856 psi) at 20 °C (68 °F)

PARKING BRAKE ACCUMULATOR RIDE CONTROL ACCUMULATOR

Capacity

2.5 L (153 in3)

Charging Pressure

3.0 MPa (30.6 kgf/cm2, 435 psi)

FAN PUMP

Theoretical Displacement

29.9 cm3/rev (1.8 in3/rev)

FAN MOTOR

Theoretical Displacement

28.2 cm3/rev (1.7 in3/rev)

OIL COOLER BYPASS CHECK VALVE

Cracking Perssure

390 kPa at 5 L/min

fNOTE: Orbitrol ® is a trade name of Eaton Corporation.

T1-3-7

SECTION 1 GENERAL Group 3 Component Specifications PARKING BRAKE SOLENOID VALVE (PARKING BRAKE SOLENOID UNIT)

Type

ON/OFF Solenoid Valve

Rated Voltage

DC 24 V

Coil Resistance

30 Ω

TORQUE CONTROL SOLENOID VALVE (MANIFOLD VALVE)

Type

Proportional Solenoid Valve

Rated Voltage

DC 24 V

Coil Resistance

10.3 Ω

CONTROL LEVER LOCK SOLENOID VALVE (MANIFOLD VALVE)

Type

ON/OFF Solenoid Valve

Rated Voltage

DC 24 V

Coil Resistance

48 Ω

FAN SPEED CONTROL SOLENOID VALVE (FAN VALVE)

Type

Proportional Solenoid Valve

Rated Voltage

DC 24 V

Coil Resistance

22 Ω

FAN REVERSE ROTATION CONTROL SOLENOID VALVE (FAN VALVE)

Type

Proportional Solenoid Valve

Rated Voltage

DC 24 V

Coil Resistance

22.3 Ω

T1-3-8

SECTION 1 GENERAL Group 3 Component Specifications Model

5WG 160

Type

Counter Shaft Type Forward 1st : 4.32 Forward 2nd : 2.19 Forward 3rd : 1.41

TRANSMISSION

Gear Ratio

Forward 4th : 0.94 Forward 5th : 0.61 Reverse 1st : 4.09 Reverse 2nd : 2.07 Reverse 3rd : 0.89

AXLE (FRONT/REAR)

PROPELLER SHAFT

Parking Brake Release Pressure

10 MPa (102 kgf/cm2, 1450 psi)

Type

Two Stage Reduction

Brake Type

Wet Multiplate Disk Brake

Brake Pressure

5.0 MPa (51 kgf/cm2, 725 psi)

Final Reduction Gear Ratio

25.767

Type

Cruciform Joint Type

Dimension between Pins

Front : 1696 mm (66.77”) Rear : 214 mm (8.42”)

T1-3-9

SECTION 1 GENERAL Group 3 Component Specifications

CYLINDER

Lift Arm

Bucket

Steering

Rod Diameter

75 mm (2.95”)

85 mm (3.35”)

45 mm (1.78”)

Cylinder Bore

125 mm (4.92”)

150 mm (5.91”)

70 mm (2.76”)

Stroke

765 mm (30.1”)

495 mm (19.5”)

442 mm (17.4”)

Fully Retracted Length 1296 mm (4’3”)

965 mm (38.0”)

804 mm (31.7”)

Plating Thickness

30 μm (1.18 μm)

T1-3-10

SECTION 1 GENERAL Group 3 Component Specifications Electrical Component FUEL LEVEL SENSOR

Resistance Value

Empty : 90+100 Ω, Full : 100-4 Ω

BATTERY RELAY

Voltage/Current

24 V/100 A

STARTER RELAY 2

Voltage

24 V

GLOW RELAY

Voltage

24 V

AIR FILTER RESTRICTION SWITCH

Operating Pressure

6.2±0.6 kPa (0.9±0.09 psi)

Voltage/Current

24 V·1.5±0.7 A

Sound Pressure

113±5 dB (A) at 2 m (6’6.7”)

Work Light

Halogen 24 V, 70 W

Cab Light

24 V, 10 W

Head Light

Halogen 24 V, 75/70 W

Turn Signal Light

24 V, 25 W (Front), 21W (Rear)

Clearance Light

24 V, 4 W (EU)/24V, 5W

License Light

24 V, 10 W×2 pcs

Tail Light

24 V, 5 W (EU)

Brake Light

24 V, 21 W

Refrigerant

134 a

Cooling Ability

4.65 kW or more

Cool Air Volume

550 m3/h (720 yard3/h) or more

Heating Ability

5.81 kW or more

Warm Air Volume

400 m3/h (523 yard3/h) or more

Temperature Adjusting System

Electronic Type

Refrigerant Quantity

900±50 g (2±0.1 lb)

Compressor Oil Quantity

160 cm3 (9.76 in3)

SECONDARY STEERING PUMP UNIT

Type

Electric Motor Operated Type

Maximum Flow

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

ELECTRIC MOTOR

Voltage

24 V, 2.4 kW

HORN

ILLUMINATION

AIR CONDITIONER

T1-3-11

SECTION 1 GENERAL Group 3 Component Specifications (Blank)

T1-3-12

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 (ECM) ........................................................ T2-2-4 Pump Control .....................................................................T2-2-39 Transmission Control (TCU) ...........................................T2-2-44 Fan Control, Valve Control .............................................T2-2-63 Control by Electrical and Hydraulic Combined Circuit...............................................................................T2-2-93

Group 3 Engine System

Air Conditioner Circuit ....................................................T2-5-24 Steering Column Box Circuit .........................................T2-5-27 Headlight Circuit ...............................................................T2-5-28 Hazard Light Circuit (Key Switch: OFF) ......................T2-5-34 Turn Signal Light Circuit .................................................T2-5-36 Horn Circuit (Key Switch: OFF) .....................................T2-5-38 Reverse Buzzer Circuit .....................................................T2-5-40 Brake Light Circuit ............................................................T2-5-42 Parking Brake Circuit........................................................T2-5-44 Accessory Circuit ...............................................................T2-5-49 Work Light Circuit .............................................................T2-5-50 Wiper Circuit .......................................................................T2-5-52 Cab Light Circuit ................................................................T2-5-58

Outline .................................................................................... T2-3-1 ECM System .......................................................................... T2-3-2 Fuel Injection Control ........................................................ T2-3-4 Fuel Injection Amount Correction Control ..............T2-3-12 EGR Control .........................................................................T2-3-14 Preheating Control ...........................................................T2-3-16 Variable Turbocharger Control .....................................T2-3-17 Alarm Control .....................................................................T2-3-18 Urea SCR System ...............................................................T2-3-19 Engine Output Restriction Control (INDUCEMENT) .............................................................T2-3-30 Aftertreatment Device ....................................................T2-3-36 Aftertreatment Device Regeneration Control ........T2-3-38

Group 4 Hydraulic System Outline .................................................................................... T2-4-1 Pilot Circuit ............................................................................ T2-4-2 Main Circuit .........................................................................T2-4-34 Fan Circuit ............................................................................T2-4-48 Secondary Steering Circuit (Option) ..........................T2-4-50

Group 5 Electrical System Outline .................................................................................... T2-5-1 Main Circuit ........................................................................... T2-5-2 Electric Power Circuit (Key Switch: OFF) ..................... T2-5-4 CAN Circuit ............................................................................ T2-5-6 Accessory Circuit (Key Switch: ACC) ............................. T2-5-8 Starting Circuit (Key Switch: START)...........................T2-5-10 Charging Circuit (Key Switch: ON) ..............................T2-5-12 Surge Voltage Prevention Circuit ................................T2-5-16 Pilot Shut-Off Circuit (Key Switch: ON) ......................T2-5-18 Auto Shut-Down Circuit (Option)................................T2-5-20 Engine Stop Circuit ...........................................................T2-5-22 70Z7B F&S (US)

(Blank)

70Z7B F&S (US)

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) TCU (Transmission Control Unit) ECM (Engine Control Module) VGS Controller Monitor Controller Column Display Controller

Controls the engine speed, pumps, and valves. Controls the transmission. Controls the engine. Operates the engine turbocharger. Displays the operating information and alarms on the monitor. Controls the wiper and buzzer, etc. Displays the gauge and alarm lights. Controls the air conditioner. Sends the e-mails and operating information.

Air Conditioner Controller Communication Controller

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

T2-1-1

Comment on Control T2-2 T2-2 T2-3 T2-3 T5-2 T2-5 T2-5, T5-7 T5-3

SECTION 2 SYSTEM Group 1 Controller 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 bus (4).

T2-1-2

SECTION 2 SYSTEM Group 1 Controller

3 5

2 4 TNEK-02-01-001

17 18

17 11

7 15 17

1 12

TNEK-02-01-002

12345-

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

6789-

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

1011121314-

T2-1-3

Communication Controller Monitor Controller MPDr. (Maintenance Pro Dr.) Air Conditioner Controller Column Display Controller

15161718-

Monitor Control Unit Information Control Unit Termination Resistor (120 Ω) CAN 3

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, and switches are sent to MC and processed in the logic circuit. MC uses the Controller Area Network (CAN) to communicate required signals to the Engine Control Module (ECM) which controls engine outputs, such as revolutions and power curve. (Refer to SYSTEM / ECM System.) MC also operates the pilot valve lockout solenoid and hydraulic pump solenoid control valve to control the pump volume and load. Transmission Control Unit (TCU) operates the transmission for machine movement. TCU sends signals on transmission range selection and machine speed to the MC by using CAN communication. TCU also operates the forward/reverse clutch solenoid valves and speed range solenoid valves, and controls the transmission.

T2-2-1

SECTION 2 SYSTEM Group 2 Control System Engine Control, Pump Control, Transmission Control < Input Signal > MC Accelerator Pedal Sensor Driving Mode Switch Power Mode Switch Pump Delivery Pressure Sensor Pressure Sensor (Parking Brake) Pressure Sensor (Brake Secondary Pressure) Hydraulic Oil Temperature Sensor Declutch Position Switch Brake Pedal (Right) Switch Lift Arm Angle Sensor

     

Pressure Sensor (Lift Arm Raise)



Key Switch Axle Oil Temperature Sensor First Speed Fixed Switch

  

Forward/Reverse Lever Forward/Reverse Switch Forward/Reverse Selector Switch Shift Switch Downshift Switch Hold Switch Torque Converter Input Speed Sensor Torque Converter Output Speed Sensor Transmission Intermediate Shaft Speed Sensor (Machine Speed Sensor (Backup)) Machine Speed Sensor Torque Converter Oil Temperature Sensor

        

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

   

ECM

Maintenance Pro Dr. (MPDr.) Monitor

 

Monitor Controller

   

TCU

 

< Output Signal > Engine Control (ECM)  Engine Protection Control  Accelerator Pedal Control  Auto-Warm Up Control  Engine Load Idle Speed Control  Forward/Reverse Idle Speed Limiter  Forward/Reverse Operation Engine Speed Limiter  Load-Free Engine High Idle Limiter  Engine Speed Regulator For Digging  First Range Engine Speed Limiter  Speed Limit Control with Power Mode OFF  Auto Power Up Speed Control  Declutch Operation Engine Speed Limiter  Machine Overheat Engine Speed Limiter  Idle Speed-Up Control While Driving with Load  Idle Speed-Up Control (Fan Reverse Rotation)  Aftertreatment Device Manual Regeneration Control

Pump Control  Base Torque Control  Torque Decrease Control While Dumping Bucket (Hydraulic Load Reduction) Transmission Control  Neutral Control  Forward/Reverse Lever Priority Control  Manual Speed Shift Control  Automatic Speed Shift Control  Downshift Control  Shift Holding Control  Speed Shift Delay Control  Declutch Control

 Controller Area Network (CAN) Column Display Controller

T2-2-2

SECTION 2 SYSTEM Group 2 Control System Fan Control, Valve Control, Other Controls < Input Signal > Accelerator Pedal Sensor Driving Mode Switch Power Mode Switch Quick Power Switch Fan Reversing Switch Pump Delivery Pressure Sensor Parking Brake Pressure Sensor Primary Pilot Pressure Sensor Primary Brake Circuit Pressure Sensor Secondary Brake Circuit Pressure Sensor Fan Pump Delivery Pressure Sensor Secondary Steering Pump Delivery Pressure Sensor (Option) Steering Pressure Switch (Option) Hydraulic Oil Temperature Sensor Declutch Position Switch Lift Arm Angle Sensor Lift Arm Raise Pressure Sensor



   

< Output Signal > Fan Control, Valve Control  Fan Speed Control  Fan Reverse Rotation Control  Lift Arm and Bucket Selection Circuit Control  Ride Control (Option)

  

Other Controls  Transmission Alarm Control  Parking Brake Operation Indicator Control  Low Brake Oil Pressure Indicator Control  Low Steering Oil Pressure Indicator Control (Option)  Overrun Alarm Control  Lift Arm Auto Leveler Height Kickout Control  Lift Arm Auto Leveler Lower Kickout Control  Quick Power Mode Control  Auto Idling Stop Control  Secondary Steering Control (Option)

        

Refrigerant Pressure Sensor Secondary Steering Check Switch (Option) Key Switch



Forward/Reverse Lever Forward/Reverse Switch Forward/Reverse Selector Switch Shift Switch Torque Converter Input Speed Sensor Torque Converter Output Speed Sensor Transmission Intermediate Shaft Speed Sensor (Machine Speed Sensor (Backup)) Torque Converter Oil Temperature Sensor Machine Speed Sensor



Coolant Temperature Sensor Crank Revolution Sensor Cam Angle Sensor Aftertreatment Device Regeneration Switch



Maintenance Pro Dr. (MPDr.) Monitor



 

TCU

Combined Electric and Hydraulic Control Circuit  Bucket Auto Leveler Control  Lift Arm Float Control

       

ECM

  



Monitor Controller 

Column Display Controller

T2-2-3

Controller Area Network (CAN)

SECTION 2 SYSTEM Group 2 Control System Engine Control (ECM) The engine control consists of the followings.  Engine Protection Control  Accelerator Pedal Control  Auto-Warm Up Control  Engine Load Idle Speed Control  Forward/Reverse Idle Speed Limiter  Forward/Reverse Operation Engine Speed Limiter  Load-Free Engine High Idle Limiter  Engine Speed Regulator For Digging  First Range Engine Speed Limiter  Speed Limit Control with Power Mode OFF  Auto Power Up Speed Control  Declutch Operation Engine Speed Limiter  Machine Overheat Engine Speed Limiter  Idle Speed-Up Control While Driving with Load  Idle Speed-Up Control (Fan Reverse Rotation)  Aftertreatment Device Manual Regeneration Control

T2-2-4

SECTION 2 SYSTEM Group 2 Control System Engine Control System Layout 44

45 46

7 22

48 42 41

8 23 24

25 40

26 16

27 24

A1 38 37

28 12 13 14 15

35 a b

OFF

c 34 11

17 30

31 32 33 TNDB-02-02-001 a-

Brake Pedal Position: Lightly applied

OFF

123456789101112131415-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Maintenance Pro (MP) Dr. Monitor Monitor Controller Engine Control Module (ECM) Engine Boost Temperature Sensor Crank Revolution Sensor Cam Angle Sensor Coolant Temperature Sensor

16- Transmission Control Unit (TCU) 17- Transmission 18- Torque Converter Oil Temperature Sensor 19- Torque Converter Input Speed Sensor 20- Torque Converter Output Speed Sensor 21- Machine Speed Sensor 22- Shift Switch 23- Forward/Reverse Lever 24- Forward Position 25- Neutral Position 26- Reverse Position

Brake Pedal Position: Fully applied

27- Forward/Reverse Switch 28- Forward/Reverse Selector Switch 29- Pump Delivery Pressure Sensor 30- Torque Control Solenoid Valve 31- Parking Brake Solenoid Valve 32- Pressure Sensor (Parking Brake) 33- Parking Brake Switch 34- Declutch Position Switch 35- Power Mode Switch 36- Travel Mode Selector Switch 37- AUTO 2 Mode 38- Manual Mode 39- AUTO 1 Mode

T2-2-5

40- Key Switch 41- Hydraulic Oil Temperature Sensor 42- Pressure Sensor (Lift Arm Raise) 43- 44- Brake Pedal (Left) 45- Pressure Sensor (Brake Secondary Pressure) 46- Brake Pedal (Right) 47- Brake Pedal (Right) Switch 48- Axle Oil Temperature Sensor

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) (3) receives the signals from coolant temperature sensor (15), hydraulic temperature sensor (41) and T/C oil temperature sensor (18), and responds by sending a signal corresponding to the target RPM's to Engine Control Module (ECM) (10) via Controller Area Network (CAN) communication (5) based on these temperature sensor signals.

F B C

D TNED-02-02-065

2. ECM (10) keeps the engine at low idle speed 800 min-1 (RPM) (F) for 3~40 seconds. 3. MC (3) automatically deactivates the engine protection control in a fixed period of time after the engine start.

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

4. At this point, ECM (10) slowly returns the engine speed (RPM or min-1) controlled by accelerator pedal (1) 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 (1) or any other operation.

T2-2-6

EF-

High Idle Speed (2350 min-1 (RPM)) Low Idle Speed (800 min-1 (RPM))

SECTION 2 SYSTEM Group 2 Control System

45 46

7 22

42 41

23 24

25 40

26 16

27 24

A1 38 37

28 12 13 14 15

35 a b

OFF

c 34 11

17 30

31 32 33 TNDB-02-02-064 a-

Brake Pedal Position: Lightly applied

OFF

123456789101112131415-

Brake Pedal Position: Fully applied

T2-2-7

SECTION 2 SYSTEM Group 2 Control System Accelerator Pedal Control Purpose: The accelerator pedal control controls the engine speed according to the accelerator pedal angle (1).

A E

Operation: 1. Main Controller (MC) (3) receives the signals from the accelerator pedal and responds by sending a signal to Engine Control Module (ECM) (10) via Controller Area Network (CAN) communication (5) based on the accelerator pedal angle.

F G B C

2. ECM (10) controls the engine speed by responding to CAN signal (5) from MC (3).

D TNED-02-02-002

3. When the signal from accelerator pedal sensor (2) is out of acceptable range, MC (3) sends a backup signals to ECM (10).

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

4. ECM (10) limits the engine speed to specified value 1000 min-1 (RPM) (F). 5. When accelerator pedal sensor (2) 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 (40) OFF. 2) Be sure the key switch (40) is OFF for at least 10 seconds. 3) Turn the key switch (40) ON. The RPM's should now be controlled by the accelerator pedal sensor. 6. After the above procedure 5 has been done, ECM (10) will recognize the signal coming from the MC (3) as provided from accelerator pedal sensor (2), according to the angle of the pedal, and the engine RPM's will be controlled by accelerator pedal (1).

T2-2-8

High Idle Speed (2350 min-1 (RPM)) F - Limited RPM's (1000 min-1 (RPM)) G - Low Idle Speed (800 min-1 (RPM)) E-

SECTION 2 SYSTEM Group 2 Control System

45 46

7 22

42 41

23 24

25 40

26 16

27 24

A1 38 37

28 12 13 14 15

35 a b

OFF

c 34 11

17 30

31 32 33 TNDB-02-02-003 a-

Brake Pedal Position: Lightly applied

OFF

123456789101112131415-

Brake Pedal Position: Fully applied

T2-2-9

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. MC (3) receives the hydraulic oil temperature signal from hydraulic oil temperature sensor (41) and coolant temperature sensor (15).

D E

2. When any one of the following conditions exists, MC (3) sends the signal equivalent to the target engine speed to ECM (10) by using CAN communication (5).  When key switch (40) is in the ON position and hydraulic oil temperature is 0 °C (32 °F) or lower  When key switch (40) is in the START position and hydraulic oil temperature is 0 °C (32 °F) or lower

B TNED-02-02-004

3. ECM (10) 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.

A - Engine Speed B - Target Engine Speed C - High Idle Speed (2350 min-1 (RPM))

4. When any one of the items under the topic below of "Deactivation Conditions" exist, MC (3) deactivates the auto-warm up control. Deactivation Conditions:  After key switch (40) has been in the START position for 10 minutes or more, the auto warm-up feature is deactivated.  Hydraulic Oil Temperature: 30 °C (85 °F) or more  Coolant Temperature: 40 °C (105 °F) or more  Parking Brake: Released 5. At this point, ECM (10) returns the engine speed (min-1 or RPM) control back to the accelerator pedal (1) position.

fNOTE: The engine low idle speed can be adjusted by

Maintenance Pro (MP) Dr. (7) or machine monitor panel (8). The auto-warm up speed can be adjusted by MPDr. (7).

IMPORTANT: When adjusting the auto-idle speed, deactivate the auto-warm up control by using monitor panel (8). 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

45 46

7 22

42 41

23 24

25 40

26 16

27 24

A1 38 37

28 12 13 14 15

35 a b

OFF

c 34 11

17 30

31 32 33 TNDB-02-02-005 a-

Brake Pedal Position: Lightly applied

OFF

123456789101112131415-

Brake Pedal Position: Fully applied

T2-2-11

SECTION 2 SYSTEM Group 2 Control System Engine Load Idle Speed Control Purpose: When the machine is climbing up an incline and the engine speed is slow, the engine load idle control engages and raises the engine RPM's from 800 RPM's (G) to 1100 RPM's (F) to prevent engine stall due to overload from application of hydraulics.

A E

Operation: 1. ECM (10) communicates the engine torque data to MC (3) via CAN communication (5).

F G

2. When all of the items under the topic below of "Conditions" exist, MC (3) sends the target engine RPM's to ECM (10) via CAN communication (5).

B C

D TNED-02-02-006

Conditions:  Forward/Reverse Lever (23): In operation  Machine Speed: 20 km/h (12.5 mph) or less  Accelerator Pedal (1) Position: Lightly applied (Engine Speed: 1000 min-1 (RPM) or less)  Engine Torque: Beyond specified value (Reference: 20 % or more)

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

3. ECM (10) increases responds by adjusting the engine RPM's up to 1100 min-1 (RPM's) (F) if the engine revolutions are less than that RPM level. This helps to prevent a load related stall.

fNOTE: Engine torque idle speed-up control is activated by the signal of forward/reverse switch (27) when it is in use on the machine.

T2-2-12

High Idle Speed (2350 min-1 (RPM)) F - Engine Load Idle Speed Speed Increase (1100 min-1 (RPM)) G - Low Idle Speed (800 min-1 (RPM)) E-

SECTION 2 SYSTEM Group 2 Control System

45 46

7 22

42 41

23 24

25 40

26 16

27 24

A1 38 37

28 12 13 14 15

35 a b

OFF

c 34 11

17 30

31 32 33 TNDB-02-02-007 a-

Brake Pedal Position: Lightly applied

OFF

123456789101112131415-

Brake Pedal Position: Fully applied

T2-2-13

SECTION 2 SYSTEM Group 2 Control System Forward/Reverse Idle Speed Limiter Purpose: The forward/reverse and steering application engine idle control increases the engine speed from 800 RPM (min-1) (G) to increased idle of 950 RPM (min-1) (F) 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 and steering application engine idle control reduces the engine speed when forward/reverse and steering are not engaged at idle in order to reduce fuel consumption and noise level.

A E

F G B

Operation: 1. Transmission Control Unit (TCU) (16) receives a signal from forward/reverse lever (23) and sends an output signal to MC (3) via Controller Area Network (CAN) communication (5). 2. When all of the items under the topic below of "Conditions" exist, MC (3) sends a target RPM (min-1) signal to ECM (10) via CAN communication (5). Conditions:  Forward/Reverse Lever (23): Forward Position (24) or Reverse Position (26)  Accelerator Pedal (1) Position: Not applied

D TNED-02-02-004

A - Engine Speed B - Accelerator Pedal Position C - Accelerator Pedal Position: Not applied D - Accelerator Pedal Position: Fully applied E - High Idle Speed (2350 min-1 (RPM))

3. ECM (10) increases the idle speed to 950 min-1 (RPM) (F) from low idle speed (G) when the engine speed is below 950 min-1 (RPM). 4. MC (3) deactivates the forward/reverse and steering application engine idle control when forward/ reverse lever (23) and steering system are in neutral position (25). 5. At this point, ECM (10) returns the engine speed (Min-1 or RPM) control back to the accelerator pedal (1) position.

fNOTE: Forward/reverse lever idle speed-up control is activated by the signal of forward/reverse switch (27) when it is in use on the machine.

T2-2-14

F-

Forward/Reverse and Steering Application Engine Idle Control (950 min-1 (RPM)) G - Low Idle Speed (800 min-1 (RPM))

SECTION 2 SYSTEM Group 2 Control System

45 46

7 22

42 41

23 24

25 40

26 16

27 24

A1 38 37

28 12 13 14 15

35 a b

OFF

c 34 11

17 30

31 32 33 TNDB-02-02-008 a-

Brake Pedal Position: Lightly applied

OFF

123456789101112131415-

Brake Pedal Position: Fully applied

T2-2-15

SECTION 2 SYSTEM Group 2 Control System Forward/Reverse Operation Engine Speed Limiter Purpose: The forward/reverse operation engine speed limiter limits the engine RPM's (min-1) while moving the machine at a fast speed. The normal engine deceleration and resulting speed reduction of the engine has an effect of slowing the machine down through the transmission and drive train. This helps to lower shock loads and material loss from the bucket.

A E

Operation: 1. Transmission Control Unit (TCU) (16) receives a signal from machine speed sensor (21), shift switch (22) and forward/reverse lever (23). TCU (16) sends an output signal to MC (3) via Controller Area Network (CAN) communication (5). 2. When all of the items under the topic below of "Conditions" exist, MC (3) sends a target RPM (min-1) signal to Engine Control Module (ECM) (10) via CAN communication (5) when forward/reverse lever (23) has been applied.

G B D

TNED-02-02-009

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

Conditions:  Machine Speed: 13 km/h (8 mph) or more  Speed Shift: Third, Fourth, or Fifth 3. ECM (10) reduces and limits the engine RPM's as shown by "Specified Value (1100 min-1) (RPM)" (F). 4. When any of the item listed under "Deactivation Conditions" exist, ECM (10) returns the engine speed (min-1 or RPM) control back to the accelerator pedal (1) position. Deactivation Conditions:  Machine Speed: 12 km/h (7.5 mph) or less  Forward/Reverse Lever (23): Neutral Position (25)

fNOTE: Forward/reverse selection speed limit control

while traveling is deactivated by the signal of forward/ reverse switch (27) when it is in use on the machine.

T2-2-16

High Idle Speed (2350 min-1 (RPM)) F - Specified Value (1100 min-1 (RPM)) G - Low Idle Speed (800 min-1 (RPM)) E-

SECTION 2 SYSTEM Group 2 Control System

45 46

7 22

42 41

23 24

25 40

26 16

27 24

A1 38 37

28 12 13 14 15

35 a b

OFF

c 34 11

17 30

31 32 33 TNDB-02-02-010 a-

Brake Pedal Position: Lightly applied

OFF

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Brake Pedal Position: Fully applied

T2-2-17

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. Main Controller (MC) (3) receives a signal from hydraulic oil pressure pump delivery pressure sensor (29).

2. When all of the items under the topic below of "Conditions" exist, MC (3) sends a target RPM (min-1) signal to ECM (10) via CAN communication (5). Conditions:  Pump Delivery Pressure: Below specified value (Reference: 14 MPa (143 kgf/cm2, 2030 psi) or less)  Forward/Reverse Lever (23) or Forward/Reverse Switch (27): Neutral Position (25)  (Machine Speed: 3 km/h (1.8 mph) or less) 3. ECM (10) reduces and limits the engine RPM's as shown below under "Specified Value" - either (F) or (G) via CAN communication (5).

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 (2350 min-1 (RPM))

Specified Value (2200 min-1 (RPM)) G - Specified Value (1750 min-1 (RPM)) H - Low Idle Speed (800 min-1 (RPM)) F-

fNOTE: When raising the lift arms with the bucket

empty, the pressure will typically be in mid-range pressures between 3 MPa (31 kgf/cm2, 435 psi) and 14 MPa (143 kgf/cm2, 2030 psi).

 Specified Value (2200 min-1) (F): Pump delivery pressure is 3 MPa (31 kgf/cm2, 435 psi) to 14 MPa (143 kgf/cm2, 2030 psi) .  Specified Value (1750 min-1) (G): Pump delivery pressure is 3 MPa (31 kgf/cm2, 435 psi) or less. 4. When any of the item listed under "Deactivation Conditions" exist, ECM (10) returns the engine speed (min-1 or RPM) control back to the accelerator pedal (1) position. Deactivation Conditions:  Pump Delivery Pressure: High Pressure (Reference: 14 MPa (143 kgf/cm2, 2030 psi) or more)  Forward/Reverse Lever (23): Forward Position (24) or Reverse Position (26)  (Machine Speed: 3 km/h (2 mph) or more)

fNOTE: Load-free engine high idle limiter is activated/

deactivated by the signal of forward/reverse switch (27) when it is in use on the machine.

T2-2-18

SECTION 2 SYSTEM Group 2 Control System

45 46

7 22

42 41

23 24

25 40

26 16

27 24

A1 38 37

28 12 13 14 15

35 a b

OFF

c 34 11

17 30

31 32 33 TNDB-02-02-012 a-

Brake Pedal Position: Lightly applied

OFF

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Brake Pedal Position: Fully applied

T2-2-19

SECTION 2 SYSTEM Group 2 Control System Engine Speed Regulator For Digging Purpose: The engine speed regulator for digging limits high idle speed and improves balance between tractive force and digging force.

A G

Operation: 1. Transmission Control Unit (TCU) (16) sends a signal indicating transmission (17) range shift (ex. 3rd  2nd range) to MC (3) via Controller Area Network (CAN) communication (5).

H I

2. Engine Control Module (ECM) (10) sends the actual engine speed signals from engine (11) to MC (3) via CAN communication (5). 3. MC (3) receives the signal from pump delivery pressure sensor (29) and the signal from power mode switch (35).

B C

Conditions:  Forward/Reverse Lever (23): Forward (F) Position (24)  Pump Delivery Pressure: High Pressure (Reference: 14 MPa (143 kgf/cm2, 2030 psi) or more)  Torque Converter Rotation Speed Ratio: Below specified value (Reference: 15 % or less) 5. ECM (10) reduces and limits the engine RPM's (min-1) to the values (H), (I) relative to the curved graph. The speed will adjust only if the RPM's are above the values shown. CAN communication (5) transfers this data as required.

Engine Speed Operating Hours (second) Roll Back Start While Rolling Back While Rolling Bucket Back Roll Back Finish

G - High Idle Speed (2350 min-1 (RPM)) H - Specified RPM While Digging I - Specified While Rolling Back Fully

Engine Speed according to Power Mode

(Reference) (Unit: min-1)

Power Mode Fast Idle Speed (G) Specified Value While Digging (H) Specified Value While Fully Digging (I)

OFF 2180 1870

ON 2350 2350

1770

2350

different according to the power mode application (ON or OFF).

calculated from the following equation.

A=B/C C-

fNOTE: Specified RPM's (H, I) of the engine speed are

fNOTE: Torque converter rotation speed ratio is A - Torque Converter Rotation Speed Ratio B - Torque Converter Output Speed

TNED-02-02-013

ABCDEF-

4. When all of the items under the topic below of "Conditions" exist, MC (3) sends a target engine speed RPM (min-1) signal to ECM (10) via CAN communication (5).

Actual Engine Speed

fNOTE: Engine Speed Regulator For Digging is activated by the signal of forward/reverse switch (27) when it is in use on the machine.

T2-2-20

SECTION 2 SYSTEM Group 2 Control System 44

45 46

7 22

42 41

23 24

25 40

26 16

27 24

A1 38 37

28 12 13 14 15

35 a b

OFF

c 34 11

17 30

31 32 33 TNDB-02-02-014 a-

Brake Pedal Position: Lightly applied

OFF

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Brake Pedal Position: Fully applied

T2-2-21

SECTION 2 SYSTEM Group 2 Control System First Range Engine Speed Limiter Purpose: The first range engine speed limiter limits the engine RPM's while in first range with the power mode ON. This lessens the load on the machine, loading system, chassis and driveline parts, and promotes economic fuel consumption.

A E F

Operation: 1. Transmission Control Unit (TCU) (16) sends the transmission (17) shift data to MC (3) via Controller Area Network (CAN) communication (5).

2. When the transmission shift lever is set to first range, MC (3) sends a target RPM (min-1) signal to ECM (10) via CAN communication (5).

B TNED-02-02-015

3. ECM (10) limits the engine RPM's (min-1) to 2190 min-1 (RPM) (F) if the RPM's are higher, or if the accelerator pedal is positioned to run the engine at high idle (E).

fNOTE: Higher priority is given to the E mode speed

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

limiter with the power mode set to OFF.

T2-2-22

High Idle Speed (2350 min-1 (RPM)) F - Specified Value (2200 min-1 (RPM)) G - Low Idle Speed (800 min-1 (RPM)) E-

SECTION 2 SYSTEM Group 2 Control System

45 46

7 22

42 41

23 24

25 40

26 16

27 24

A1 38 37

28 12 13 14 15

35 a b

OFF

c 34 11

17 30

31 32 33 TNDB-02-02-016 a-

Brake Pedal Position: Lightly applied

OFF

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Brake Pedal Position: Fully applied

T2-2-23

SECTION 2 SYSTEM Group 2 Control System Speed Limit Control with Power Mode OFF Purpose: The E mode speed limiter limits the high idle speed according to propulsion load when the power mode is deactivated (OFF, or so-called E mode). Therefore, fuel consumption is reduced.

Speed Shift: less than Second

Operation: 1. Transmission Control Unit (TCU) (16) receives a signal about machine speed from transmission (17) and sends a signal to Main Controller (MC) (3) via Controller Area Network (CAN) communication (5).

2. Engine Control Module (ECM) (10) sends the actual engine speed data from engine (11) to MC (3) via CAN communication (5). 3. When power mode switch (35) is OFF, MC (3) sends a target RPM (min-1) a signal to ECM (10) via CAN communication (5). B

fNOTE: When fourth or fifth range is selected, the E

TNED-02-02-058KC

mode speed limiter is deactivated.

fNOTE: E mode speed limiter is activated by the signal

A - Engine Speed

from forward/reverse switch (27) when it is in use on the machine.

B-

Propulsion Load

fNOTE: When key switch (40) is set to the OFF position, the power mode is turned OFF.

4. ECM (10) reduces and limits the engine speed to the specified value from the high idle speed according to CAN communication (5) when the engine speed is above the limited engine speed engaged by the E mode speed limiter.  When the selected range is second or first, the engine speed is limited to a given value as indicated in the chart. The engine speed value is relative to the propulsion load.  When third range is selected, the engine speed is limited from higher revolutions to 2150 min-1 (RPM's).

MC (3) detects driving load by using the torque converter speed ratio. The torque converter speed ratio is calculated from the following equation. J=K/L J-

T2-2-24

Torque Converter Speed Ratio

KL-

Torque Converter Output Speed Actual Engine Speed

SECTION 2 SYSTEM Group 2 Control System 44

45 46

7 22

42 41

23 24

25 40

26 16

27 24

A1 38 37

28 12 13 14 15

35 a b

OFF

c 34 11

17 30

31 32 33 TNDB-02-02-019 a-

Brake Pedal Position: Lightly applied

OFF

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Brake Pedal Position: Fully applied

T2-2-25

SECTION 2 SYSTEM Group 2 Control System Auto Power Up Speed Control Purpose: When the speed limit control with power mode OFF is activated with the power mode set at OFF and when driving load climbing on a slope is kept for the specified time, the engine speed increases to two stages and machine speed climbing on a slope is improved.

Operation: 1. When the speed limit control with power mode OFF is activated, MC (3) sends the signal equivalent to the target engine speed to ECM (10) by using CAN communication (5).

2. ECM (10) increases the engine speed to two stages (C, D) according to CAN communication (5).  Engine Speed (C): The torque converter speed ratio is kept at the specified range (reference: between 0.4 and 0.65) for one seond.  Engine Speed (D): The torque converter speed ratio is kept at the specified range (reference: between 0.4 and 0.65) for two seonds. Deactivation: 1. When any one of the following conditions exists, MC (3) deactivates the auto power up speed control.  The torque converter speed ratio is kept at the specified value (reference: 0.9) for three seonds.  Forward/Reverse Lever: Operated

TNEK-02-02-001 A - Engine Speed B - Driving Load

CD-

Specified Value Specified Value

fNOTE: When key switch (40) is set to the OFF position, the power mode is turned OFF.

fNOTE: MC (3) detects driving load by using the torque

converter speed ratio. The torque converter speed ratio is calculated from the following equation.

J=K/L J-

Torque Converter Speed Ratio

KL-

T2-2-26

Torque Converter Output Shaft Speed Actual Engine Speed

SECTION 2 SYSTEM Group 2 Control System

45 46

7 22

42 41

23 24

25 40

26 16

27 24

A1 38 M 37

28 12 13 14 15

35 a b

OFF

c 34 11

17 30

31 32 33 TPD8-02-02-019 a-

Brake Pedal Position: Lightly applied

OFF

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Brake Pedal Position: Fully applied

T2-2-27

SECTION 2 SYSTEM Group 2 Control System Declutch Operation Engine Speed Limiter Purpose: The declutch operation engine speed limiter limits the high idle speed and the increase of engine speed when declutch is active. This controls energy loss. (Transmission Control/ Declutch Control.)

A E F

Operation: 1. Main Controller (MC) (3) receives a signal from declutch position switch (34). G

2. When all of the items under the topic below of "Conditions" exist, MC (3) sends a target RPM (min-1) to Engine Control Module (ECM) (10) via Controller Area Network (CAN) communication (5). Conditions:  Declutch Position Switch (34): (c) Position  Power Mode Switch (35): ON (Power Mode is activated) 3. ECM (10) reduces and limits the engine speed to 2200 min-1 (RPM) (F) from high idle speed (E) when the engine speed is above 2,200 min-1 (RPM) or when the accelerator pedal is set to run the engine at a higher speed.

B TNED-02-02-015

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

4. Therefore, engine speed is limited during declutch operation.

fNOTE: Since the engine speed is limited with use of

declutch position switch (34) set at (a) position, the declutch operation engine speed limiter is deactivated.

T2-2-28

High Idle Speed (2350 min-1 (RPM)) F - Specified Value (2200 min-1 (RPM)) G - Low Idle Speed (800 min-1 (RPM)) E-

SECTION 2 SYSTEM Group 2 Control System

45 46

7 22

42 41

23 24

25 40

26 16

27 24

A1 38 M 37

28 12 13 14 15

35 a b

OFF

c 34 11

17 30

31 32 33 TNDB-02-02-020 a-

Brake Pedal Position: Lightly applied

OFF

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Brake Pedal Position: Fully applied

T2-2-29

SECTION 2 SYSTEM Group 2 Control System Machine Overheat Engine Speed Limiter Purpose: The machine overheat engine speed limiter limits the high idle speed and resists overheating when the engine coolant and torque converter oil temperatures reach their upper limit. Operation: 1. Engine Control Module (ECM) (10) receives signals from coolant temperature sensor (15). ECM (10) sends a signals to Main Controller (MC) (3) via Controller Area Network (CAN) communication (5).

A F H G

2. Transmission Control Unit (TCU) (16) receives a signal from torque converter oil temperature sensor (18). TCU (16) sends a signal to MC (3) via CAN communication (5). 3. MC (3) receives the signal from the axle oil temperature sensor (48).

4. When any one of the items under the topic below of "Conditions" exist, MC (3) sends a target RPM (min-1) signal to ECM (10) via CAN communication (5). Conditions:  Coolant Temperature: 97 °C (205 °F) or more  Torque Converter Oil Temperature: 103 °C (217 °F) or more  Axle Oil Temperature: over 92 °C (198 °F) 5. ECM (10) reduces and limits the engine speed to 2130 min-1 (RPM) (H) or 2030 min-1 (RPM) (G) from high idle speed (F) relative to the temperature of each component when the RPM's (min-1) are above the limited speed of the machine overheat engine speed limiter.

C D E TNEE-02-02-022

A - Engine Speed B - Temperature C - Axle Oil Temperature (92 °C, 198 °F) D - Coolant Temperature (97 °C, 205 °F) E - Torque Converter Oil Temperature (103 °C, 217 °F)

6. Therefore, the engine overheating is prevented.

T2-2-30

High Idle Speed (2350 min-1 (RPM)) G - Specified Value (2030 min-1 (RPM)) H - Specified Value (2130 min-1 (RPM)) F-

SECTION 2 SYSTEM Group 2 Control System

45 46

7 22 48 8

42 41

23 24

25 40

26 16

27 24

A1 38 M 37

28 12 13 14 15

35 a b

OFF

c 34 11

17 30

31 32 33 TNDB-02-02-023 a-

Brake Pedal Position: Lightly applied

OFF

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Brake Pedal Position: Fully applied

T2-2-31

SECTION 2 SYSTEM Group 2 Control System Idle Speed-Up Control While Driving with Load Purpose: The idle speed-up control while driving with load increases the engine speed from the forward/reverse lever idle speed-up speed and prevents the engine stall. (Refer to Forward/Reverse Lever Idle Speed-Up Control.)

A E

Operation: 1. When all following conditions exist, MC (3) sends the signal equivalent to the target engine speed to ECM (10) by using CAN communication (5).  Speed Shift: Third to Fifth Speed Forward or Third Speed Reverse  Machine Speed: over 12 km/h (7.5 mph)  Accelerator Pedal (1) Depressing Amount: Lightly (Engine Speed: less than 1100 min-1 or 1200 min-1)  Torque Converter Speed Ratio: over specified value (Reference: over 120 %) 2. ECM (10) increases the engine speed to the idle speed-up speed while driving with load (H) from the forward/reverse lever idle speed-up speed (F). Deactivation: 1. When any one of the following condition exists, ECM (10) returns the engine speed according to the accelerator pedal control.

H F G B C

D TNED-02-02-062

A - Engine Speed B - Accelerator Pedal Depressing Amount C - Accelerator Pedal Depressing Amount: Not depressed D - Accelerator Pedal Depressing Amount: Fully Depressed

Fast Idle Speed (2350 min-1) Forward/Reverse Lever Idle Speed-Up Speed (950 min-1) G - Slow Idle Speed (800 min-1) H - Idle Speed-Up Speed While Driving with Load

EF-

fNOTE: The idle speed-up speed while driving with load

 Forward: Machine Speed: less than 7 km/h (4.3 mph) and Torque Converter Speed Ratio: less than specified value (Reference: less than 80 %)  Reverse: Machine Speed: less than 9 km/h (5.6 mph) and Torque Converter Speed Ratio: less than specified value (Reference: less than 80 %)  After 7 seconds when the idle speed-up control while driving with load is activated

T2-2-32

(H) is different depending on driving direction. Forward: 1100 min-1

Reverse: 1200 min-1

SECTION 2 SYSTEM Group 2 Control System

45 46

7 22

42 41

23 24

25 40

26 16

27 24

A1 38 37

28 12 13 14 15

35 a b

OFF

c 34 11

17 30

31 32 33 TNDB-02-02-002 a-

Brake Pedal Position: Lightly applied

OFF

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Brake Pedal Position: Fully applied

T2-2-33

SECTION 2 SYSTEM Group 2 Control System Idle Speed-Up Control (Fan Reverse Rotation) Purpose: The idle speed-up control (fan reverse rotation) increases the engine speed from slow idle speed and prevents the fan reverse rotation from stopping when suddenly releasing the accelerator pedal during fan reverse rotation control. (Refer to Fan Reverse Rotation Control.)

Operation: 1. MC (3) receives the signal from fan reverse rotation switch (49).

2. When all following conditions exist, MC (3) sends the signal equivalent to the target engine speed to ECM (10) by using CAN communication (5).  Forward/Reverse Lever (23): Neutral Position (25)  When shifting the fan reverse rotation or when turning the fan in reverse 3. ECM (10) increases the engine speed to idle speedup speed (F) (fan reverse rotation). 4. When any one of the following conditions exists, MC (3) deactivates the idle speed-up control (fan reverse rotation).

B C

D TNED-02-02-004

A - Engine Speed B - Accelerator Pedal Depressing Amount C - Accelerator Pedal Depressing Amount: Not depressed D - Accelerator Pedal Depressing Amount: Fully depressed E - Fast Idle Speed (2350 min-1)

 Forward/Reverse Lever (23): Forward Position (24) or Reverse Position (26)  When turning the fan in normal 5. Therefore, ECM (10) returns the engine speed according to the accelerator pedal control.

fNOTE: When the fan auto-reverse rotation (Option)

mode is selected, the idle speed-up control (fan reverse rotation) is disabled.

fNOTE: The idle speed-up control (fan reverse rotation) is activated according to forward/reverse switch (27) in case of the machine equipped with forward/reverse switch (27).

T2-2-34

F-

Idle Speed-Up Speed (Fan Reverse Rotation) (1050 min1 ) G - Slow Idle Speed (800 min-1)

SECTION 2 SYSTEM Group 2 Control System 44

45 46

7 22

42 41

23 24

25 40

26 16

27 24

A1 38 M 37

28 12 13 14 15

35 a b

OFF

c 34 11

49 30

31 32 33 TNDB-02-02-006 a-

Brake Pedal Position: Lightly applied

OFF

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Brake Pedal Position: Fully applied

T2-2-35

SECTION 2 SYSTEM Group 2 Control System Aftertreatment Device Manual Regeneration Control Purpose: The aftertreatment device regeneration control increases the engine speed and applies load to the engine. Therefore, this control assists to increase the exhaust temperature up to the temperature that a catalyst in the aftertreatment device is activated. Operation: 1. When manual regeneration of the aftertreatment device is required, Engine Control Module (ECM) (8) sends the aftertreatment device regeneration request signal to Main Controller (MC) (1) by using Controller Area Network (CAN) communication (5). (Refer to SYSTEM/Engine System/Aftertreatment Device Regeneration Control) 2. When all of the items under the topic below of "Conditions" exist, MC (1) sends the aftertreatment device regeneration request signal to ECM (8) via CAN communication (5). Conditions:  Manual Regeneration Switch (9): ON  Accelerator Pedal (2) Position: Not depressed  Parking Brake: Applied  Forward/Reverse Lever (17): Neutral Position (19)  Control Lever Lock: Operated [Pressure Sensor (Primary Pilot Pressure) (28): less than specified value] 3. ECM (8) increases the engine speed and increases the exhaust temperature up to the temperature that a catalyst in the aftertreatment device is activated.

fNOTE: Aftertreatment device regeneration control is activated by the signal of forward/reverse switch (21) when it is in use on the machine.

T2-2-36

SECTION 2 SYSTEM Group 2 Control System

28 6

19 20

18 5 19 1 20

11 12 13 14

16 24

26 27

TNEE-02-02-052

12345678-

Main Controller (MC) Accelerator Pedal Accelerator Pedal Sensor Column Display Controller Controller Area Network (CAN) Monitor Monitor Controller Engine Control Module (ECM)

9101112131415-

Manual Regeneration Switch Engine Exhaust Temperature Sensor Crank Revolution Sensor Cam Angle Sensor Coolant Temperature Sensor Transmission Control Unit (TCU)

16171819202122-

T2-2-37

Transmission Forward/Reverse Lever Forward Position Neutral Position Reverse Position Forward/Reverse Switch Forward/Reverse Selector Switch

23242526-

Pump Delivery Pressure Sensor Torque Control Solenoid Valve Parking Brake Solenoid Valve Pressure Sensor (Parking Brake) 27- Parking Brake Switch 28- Pressure Sensor (Primary Pilot Pressure)

SECTION 2 SYSTEM Group 2 Control System (Blank)

T2-2-38

SECTION 2 SYSTEM Group 2 Control System Pump Control The pump control consists of the followings.  Base Torque Control  Bucket Dump Hydraulic Load Reduction

T2-2-39

SECTION 2 SYSTEM Group 2 Control System Base Torque Control Purpose: The base torque control controls the hydraulic pump delivery flow rate in response to the engine speed changes due to variations in load so that the engine output power can be used more efficiently.

Operation: 1. The target engine speed can be set by the depressing amount of accelerator pedal (1). (Refer to Accelerator Pedal Control.) 2. Engine Control Module (ECM) (10) receives the signals from cam angle sensor (14) and crank speed sensor (13). 3. ECM (10) sends the calculated engine speed signal to MC (3) by using CAN communication (5). 4. MC (3) sends a signal to hydraulic pump load torque control solenoid valve (30) relative to the actual engine speed as communicated by CAN communication (5) from ECM (10).

P TNED-02-02-024

5. Torque control solenoid valve (30) delivers pilot pressure oil to the regulator depending on the signal received to control the pump delivery flow rate.

P-

Therefore, the engine load is reduced and the engine stall is prevented.

fNOTE: Refer to Bucket Dump Hydraulic Load Reduction while dumping the bucket.

T2-2-40

Pressure

Q - Flow Rate

SECTION 2 SYSTEM Group 2 Control System 44

45 46

7 22

42 41

23 24

25 40

26 16

27 24

A1 38 37

28 12 13 14 15

35 a b

OFF

c 34 11

17 30

31 32 33 TNDB-02-02-025 a-

Brake Pedal Position: Lightly applied

OFF

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Brake Pedal Position: Fully applied

T2-2-41

SECTION 2 SYSTEM Group 2 Control System Bucket Dump Hydraulic Load Reduction Purpose: The bucket dump hydraulic load reduction feature reduces pump oil flow and load so that the power from the engine can be applied to forward movement of the machine. Operation: 1. When all of the items under the topic below of "Conditions" exist, Main Controller (MC) (3) sends a signal to torque control solenoid valve (30). 2. Torque control solenoid valve (30) adjusts the hydraulic oil flow delivery rate at the regulator relative to the electrical signal it receives from the MC (3). Conditions:  Torque Converter Rotation Speed Ratio: Below specified value (Reference: 15 % or less)  Forward/Reverse Lever (23): Forward Position (24)  Pump Delivery Pressure (29): High Pressure (Reference: 14 MPa (143 kgf/cm2, 2030 psi) or more)

fNOTE: The torque converter speed ratio is calculated from the following equation.

J=K/L JK-

Torque Converter Speed Ratio Torque Converter Output Speed

L-

Actual Engine Speed

fNOTE: Bucket Dump Hydraulic Load Reduction is

activated by the signal from forward/reverse switch (27) when it is in use on the machine.

T2-2-42

SECTION 2 SYSTEM Group 2 Control System 44

45 46

7 22

42 41

23 24

25 40

26 16

27 24

A1 38 M 37

28 12 13 14 15

35 a b

OFF

c 34 11

17 30

31 32 33 TNDB-02-02-026 a-

Brake Pedal Position: Lightly applied

OFF

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Brake Pedal Position: Fully applied

T2-2-43

SECTION 2 SYSTEM Group 2 Control System Transmission Control (TCU) The transmission control consists of the following.  Neutral Control  Forward/Reverse Lever Priority Control  Manual Speed Range Control  Automatic Speed Shift Control  Downshift Control  Speed Shift Delay Control  Declutch Control  Shift Holding Control

T2-2-44

SECTION 2 SYSTEM Group 2 Control System

41 42

2 11

12 23

47 6

45 44

24 25

27 38 37 36 35

A1 M A2

34 a b

28 25

OFF

16 17 18

33 13 9 21 19 20 30 22 32

31 TPD8-02-02-027

Brake Pedal Position: Lightly applied

12345678910-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) Column Display Controller Controller Area Network (CAN Monitor Monitor Controller Engine Control Module (ECM) Engine Transmission Control Unit (TCU) Downshift Switch (DSS) Hold Switch Transmission Torque Converter Oil Temperature Sensor

15- Torque Converter Input Speed Sensor 16- Torque Converter Output Speed Sensor 17- Transmission Intermediate Shaft Speed Sensor 18- Machine Speed Sensor 19- Slow-Speed Forward Clutch Solenoid Valve (Y5) 20- Fast-Speed Forward Clutch Solenoid Valve (Y1) 21- Reverse Clutch Solenoid Valve (Y2) 22- Speed Shift Solenoid Valve (1 (Y3), 2 (Y6), 3 (Y4)) 23- Shift Switch

11121314-

OFF

Brake Pedal Position: Fully applied

242526272829-

Forward/Reverse Lever Forward Position Neutral Position Reverse Position Forward/Reverse Switch Forward/Reverse Selector Switch Parking Brake Solenoid Valve Pressure Sensor (Parking Brake) Parking Brake Switch Declutch Position Switch Power Mode Switch Travel Mode Selector Switch AUTO 2 Mode Manual Mode

3031323334353637-

T2-2-45

38394041424344454647-

AUTO 1 Mode Key Switch Brake Pedal (Left) Pressure Sensor (Brake Secondary Pressure) Brake Pedal (Right) Brake Pedal (Right) Switch Lift Arm Angle Sensor Pressure Sensor (Lift Arm Raise) First Speed Fixing Switch

SECTION 2 SYSTEM Group 2 Control System Neutral Control Purpose: The neutral control deactivates the forward/reverse lever (24) operation and does not connect the transmission forward/reverse clutches when the parking brake is applied. Therefore, the parking brake is prevented from dragging. 1. Main Controller (MC) (3) receives a signal from parking brake pressure sensor (31). 2. The ON/OFF signal of parking brake is sent from MC (3) to Transmission Control Unit (TCU) (10) via column display controller (4). 3. TCU (10) receives the signal from forward/reverse lever (24). (Refer to Forward/Reverse Lever Priority Control.) 4. TCU (10) reads the parking brake pressure sensor (31) input signal from MC (3) via Control Area Network (CAN) communication (5) when operating forward/reverse lever (24). 5. Parking brake solenoid valve (30) opens the circuit between the parking brake actuator and the hydraulic oil tank and engages the parking brake. This is done via use of parking brake switch (32). The parking brake is applied with spring force, and releases with oil pressure. 6. When the parking brake is applied, TCU (10) does not respond to the signal from forward/reverse lever (24). Thus forward/reverse clutch solenoid valves (19, 20 and 21) of transmission (13) will not be energized when the parking brake is applied and the parking brake does not receive pressure to be released (pressure sensor at parking brake (31) is below the specified pressure). 7. Therefore, the forward/reverse clutch of transmission (13) is not engaged when the parking brake is applied. Transmission (13) is set to the neutral.

fNOTE: The parking brake solenoid valve (30) returns pilot pressure oil to the hydraulic oil tank from the parking brake according to the ON signal of parking brake switch (32). The parking brake is applied by the spring force.

fNOTE: The neutral control is also activated when the

signal of forward/reverse switch (28) is effective in case of the machine equipped with forward/reverse switch (28).

T2-2-46

SECTION 2 SYSTEM Group 2 Control System

41 42

2 11

12 23

47 6

45 44

24 25

27 38 37 36 35

A1 M A2

34 a b

28 25

OFF

16 17 18

33 13 9 21 19 20 30 22 32

31 TPD8-02-02-028

Brake Pedal Position: Lightly applied

12345678910-

11121314-

OFF

Brake Pedal Position: Fully applied

242526272829-

3031323334353637-

T2-2-47

38394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Forward/Reverse Lever Priority Control Purpose: The forward/reverse lever is given priority over the forward/reverse switch (28) when the machine forward/ reverse movement is controlled by forward/reverse switch (28). Operation: 1. Forward/reverse lever (24), forward/reverse switch (28), and forward/reverse selector switch (29) all send a signal to the Transmission Control Unit (TCU) (10). When TCU (10) receives these signals, it then responds with an output signal to the forward/ reverse clutch solenoid valves (19 , 20, and 21) of transmission (13). 2. When forward/reverse selector switch (29) is OFF, TCU (10) responds to forward/reverse lever (24) only. 3. When forward/reverse selector switch (29) has been turned ON with both forward/reverse lever (24) and forward/reverse switch (28) are put in the neutral position (26), TCU (10) will act on the next input from forward/reverse switch (28). 4. When forward/reverse lever (24) is used, it is given priority by TCU (10) over forward/reverse switch (28). 5. To use forward/reverse switch (28) again, go back to step 3.

fNOTE: In case forward/reverse lever (24) fails, TCU

(10) sets transmission (13) in neutral via the backup control feature. In case forward/reverse switch (28) fails, directional input control is given to forward/reverse lever (24).

T2-2-48

SECTION 2 SYSTEM Group 2 Control System

41 42

2 11

12 23

47 6

45 44

24 25

27 38

28 25

37 36

M A2

34 a b

OFF

c 33

16 17 18

13 9 21 19 20 30 22 32

31 TPD8-02-02-029

Brake Pedal Position: Lightly applied

12345678910-

11121314-

OFF

Brake Pedal Position: Fully applied

242526272829-

3031323334353637-

T2-2-49

38394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Manual Speed Shift Control Purpose: The manual speed shift control changes the selected transmission range manually. Operation: 1. Main Controller (MC) (3) receives a signal to manually control the transmission from operating mode switch (35) and first speed fixing switch (47). MC (3) sends a signal to Transmission Control Unit (TCU) (10) via Controller Area Network (CAN) communication (5). (Refer to Automatic Speed Shift Control.)

 Limit of Speed Shift 1. TCU (10) also limits the range selection when this would be damaging to the transmission. For example, if the selected ranges were quickly changed from fourth to second at an excessive speed, first range would not be selected since this would damage the transmission. 2. TCU (10) changes the downshifting ranges a step at a time so as not to damage transmission (13); i.e. from fifth to fourth, from fourth to third, etc. These step by step shifts are done according to the machine speed. This protects the transmission by reducing downshift shock loads.

2. TCU (10) receives a signal from machine speed sensor (18) and shift switch (23). Shift switch (23) is divided into two sections.

 Fixing at 1st Speed 1. TCU (10) holds the transmission (13) shift in first range when second range is selected by shift switch (23) and first speed fixing switch (47) is turned ON.

Notice the two sides, "SW1" and "SW2" in the table below. When second range is selected, "Side SW1" would be "ON" and "Side SW2" would be "OFF". When third range is selected, both "Side SW1" and "Side SW2" would remain in the "OFF" position, as the table shows. This signal is sent to TCU (10) and it provides an appropriate output to control transmission (13). Speed Shift Inside Switch (SW 1) Inside Switch (SW 2)

2nd ON

3rd

4th ON

2. As this is occurring, TCU (10) sends a signal to monitor controller (7) via CAN communication (5) to indicate on the monitor panel which transmission range is currently applied. 3. Monitor controller (7) displays the applied range on monitor panel (6).

5th ON ON

fNOTE: Ranges available for selection are five forward and three reverse.

3. The speed range signal from shift switch (23) is sent to TCU (10) which responds with an output signal to speed range solenoid valve (22) of transmission (13) when operation mode switch (35) is on manual mode (37). This changes the selected range of transmission (13) manually.

T2-2-50

SECTION 2 SYSTEM Group 2 Control System

41 42

2 11

12 23

47 6

45 44

24 25

27 38

28 25

37 36

M A2

34 a b

OFF

c 33

16 17 18

13 9 21 19 20 30 22 32

31 TPD8-02-02-030

Brake Pedal Position: Lightly applied

12345678910-

11121314-

OFF

Brake Pedal Position: Fully applied

242526272829-

3031323334353637-

T2-2-51

38394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Automatic Speed Shift Control Purpose: The automatic speed shift control changes the speed shift of transmission automatically. The shift change mode can be selected according to the work mode or work condition requirements. In addition, the timing of automatic speed shift is changed according to the power mode application to help with reducing fuel consumption and maintain the performance.

fNOTE: The speed range selection is five forward and three reverse. Additionally, the automatic mode on forward/reverse lever (23) provides the highest speed range.

fNOTE: When forward/reverse lever (23) is set to second

range and first speed fixing switch (47) is turned ON, transmission (13) remains in AUTO 1 (38) or AUTO 2 (36).

fNOTE: When travel mode switch (35) becomes

Operation: 1. Main Controller (MC) (3) receives an input signal from travel mode selector switch (35) and power mode switch (34). MC (3) sends signals to Transmission Control Unit (TCU) (10) via Controller Area Network (CAN) communication (5).

malfunctions, MC (3) sets the driving shift change mode to manual mode.

fNOTE: When machine speed sensor (18) becomes

malfunctions, TCU (10) sets the speed range of transmission (13) to second via TCU (10) backup control.

2. TCU (10) receives speed shift signal from transmission (13), signals from machine speed sensor (18) and shift switch (23). 3. TCU (10) sends the speed shift signal to speed shift solenoid valve (22) of transmission (13) in response to the input signal. Transmission (13) will automatically shift as required by the operating conditions. Travel (Shift Change) Mode  AUTO 1 Mode (38): The machine starts out in second range. When operating load is high, it will automatically downshift from second to first range.  AUTO 2 Mode (36): The machine starts out in second range. When operating load is high, it will not automatically downshift to first speed range.  Manual (37): The speed range is selected manually. (Refer to Manual Speed Shift Control.) Power Mode:  OFF (E Mode): The transmission shifts up to the next range more quickly than usual. This improves the rate of fuel consumption while operating the machine in low load conditions.  ON (P Mode): The transmission shifts up to the next range less quickly than usual. This improves the operation of the machine while under high load conditions.

T2-2-52

SECTION 2 SYSTEM Group 2 Control System

41 42

2 11

12 23

47 6

45 44

24 25

27 38

28 25

37 36

M A2

34 a b

OFF

c 33

16 17 18

13 9 21 19 20 30 22 32

31 TPD8-02-02-031

Brake Pedal Position: Lightly applied

12345678910-

11121314-

OFF

Brake Pedal Position: Fully applied

242526272829-

3031323334353637-

T2-2-53

38394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Downshift Control Purpose: The downshift control permits transmission (13) to downshift to the next lower range when it is applied.

7. When any of the following conditions exists under the topic "Deactivation Conditions", the downshift control is deactivated.

Operation: 1. Transmission Control Unit (TCU) (10) receives the signals from machine speed sensor (18), shift switch (23), and downshift switch (DSS) (11) and the currently applied range within transmission (13). 2. When downshift switch (11) is applied, TCU (10) downshifts by one range when the machine speed reaches the target speed for downshift (as from 4 to 3, from 3 to 2, etc.). TCU (10) sends the shift signal to solenoid valve (22) of transmission (13) to downshift the speed range to the nex one.

Deactivation Conditions:  Forward/Reverse Lever (24): In use  Driving Mode Switch (35): In use  Shift Switch (23): Operated  At 3 seconds after the downshift control is activated

fNOTE: Downshift switch (11) is located on a front attachment control lever.

fNOTE: When machine speed sensor (18) malfunctions, TCU (10) sets the speed range of transmission (13) to second via TCU back up control.

fNOTE: Downshift control is deactivated by the signal

3. With AUTO1 (38) or AUTO2 (36) shift change mode selected, when driving machine while holding downshift switch (11) depressed, TCU (10) downshifts the speed range from fourth to third, then from third to second by one range automatically when the machine speed reaches the target speed, and holds the speed range in second until releasing the downshift switch (11). 4. By applying downshift switch (DSS) (11) within 3 seconds after releasing it, TCU (10) changes downshifts the speed range from second to first when the machine speed reaches the target speed for downshift. 5. The downshift control is deactivated and is returned to automatic speed shift control in 3 seconds after the speed shift is lowered. (Refer to Automatic Speed Shift Control.) 6. With the Manual (37) shift change mode selected, TCU (10) downshifts the speed range by applying downshift switch (DSS) (11) by one range when the machine speed reaches the target speed for downshift. The selected shift range is held after lowering to the next one down. Apply downshift switch (11) again to downshift to the next one down. (Refer to Manual Speed Shift Control.)

T2-2-54

of forward/reverse switch (28) when it is in use on the machine.

SECTION 2 SYSTEM Group 2 Control System

41 42

2 11

12 23

47 6

45 44

24 25

27 38

28 25

37 36

M A2

34 a b

OFF

c 33

16 17 18

13 9 21 19 20 30 22 32

31 TPD8-02-02-032

Brake Pedal Position: Lightly applied

12345678910-

11121314-

OFF

Brake Pedal Position: Fully applied

242526272829-

3031323334353637-

T2-2-55

38394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Speed Shift Delay Control Purpose: The transmission shift delay control holds back the upshift timing at automatic speed shift control. Therefore, this control maintains machine performance during bucket and lift arm movement while loading.

fNOTE: The speed shift delay control can be set or deactivated with monitor controller (7).

Operation: 1. When the following items listed below under "Requirements" and "Any Satisfied Conditions" exist, the timing of shift up (from 2nd to 3rd speed) is delayed at automatic speed shift control. Requirements:  Forward/Reverse Lever (24) or Forward/Reverse Switch (28): Forward Position (25) or Reverse Position (27)  Shift Change Mode Switch (35): AUTO 1 mode (38), AUTO 2 mode (36)  Machine Speed: Beyond specified value (Reference: Power Mode OFF: 9.4 km/h (5.8 mph) or more, Power Mode ON: 10.3 km/h (6.4 mph) or more)  Speed Shift: Second  Parking Brake: Unlock

A C B

TNED-02-02-059

AB-

Any Satisfied Conditions:  Lift Arm Lower Operation (Lift Arm Angle Sensor (44): ON (Dumping, Loading Positions))  Pressure Sensor (Lift Arm Raise) (45): Signal (This signal is not seen as valid until a minimum of 3 seconds of application have past.) 2. Transmission Control Unit (TCU) (10) delays the current speed shift signal for 4 seconds while in forward and 5 seconds while in reverse with the machine in motion. 3. The speed shift of transmission (13) is changed from 2nd speed to 3rd speed when the specified time has passed. 3. Therefore, the upshift timing of speed-shift up (second to third speed) is delayed.

fNOTE: Speed shift delay control is activated by the

signal of forward/reverse switch (28) when it is in use on the machine.

T2-2-56

Loading Position Setup Range of Lift Arm Rollback Position Setup Range of Lift Arm

C-

Horizontal Position of Lift Arm

SECTION 2 SYSTEM Group 2 Control System

41 42

2 11

12 23

47 6

45 44

24 25

27 38

28 25

37 36

M A2

34 a b

OFF

c 33

16 17 18

13 9 21 19 20 30 22 32

31 TPD8-02-02-033

Brake Pedal Position: Lightly applied

12345678910-

11121314-

OFF

Brake Pedal Position: Fully applied

242526272829-

3031323334353637-

T2-2-57

38394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Declutch Control 6. When any one of the items listed under "Deactivation Conditions" exists, MC (3) sends the clutch cutoff signal to TCU (10) by using CAN communication (5).

Purpose: The declutch control disengages the forward or reverse clutches (whichever engaged at the time) by applying the brake pedal. With the drivetrain not drawing torque from the engine, the power can be concentrated on the loading circuit functions. Operation: 1. Main Controller (MC) (3) receives a signal from declutch position switch (33). 2. When all the items listed under "Conditions" exist, TCU(10) stops energizing slow-speed forward clutch solenoid valve (Y5) (19), fast-speed forward clutch solenoid valve (Y1) (20), or reverse clutch solenoid valve (Y2) (21) of transmission (13). In this state, neither forward/reverse clutches are engaged. Conditions:  Declutch Position Switch (33): (a) or (c) Position (Brake Pedal (Left) (40): Lightly or Fully Applied)  Speed Range: Second or less  Machine speed: 20 km/h (12.5 mph) or less  Pressure Sensor (Brake Second Pressure) (41): Above specified pressure

Deactivation Conditions:  Declutch Position Switch (33): OFF Position  Speed Range: Third speed or more  Machine Speed: 20 km/h (12.5 mph) or more  Brake: Applied (Brake Pedal (Right) (42): Depressed)  Pressure Sensor (Brake Second Pressure) (41): Below specified pressure 2. TCU(10) activates forward/reverse clutch solenoid valves (19, 20, and 21) of transmission (13). 3. Transmission (13) connects the forward/reverse clutches.

fNOTE: The fast idle speed of the engine is decreased

and the engine speed increase is limited by cutting the driving power at the clutch cutoff control. (Refer to Engine Control/Speed Limit Control During Clutch Cut Operation.)

fNOTE: If the clutch cut position switch (34) and pressure

3. Consequently, the engine output power can be concentrated on the loading circuit functions.

sensor (brake second pressure) (41) become abnormal, the clutch cutoff control is deactivated.

4. The forward/reverse clutches of transmission (13) are disconnected. 5. Monitor (6) displays the forward/reverse position even when the forward/reverse clutches are in the neutral at the clutch cutoff control. Declutch Position (Left Brake Pedal (40) Position) Accelerator Pedal (1) Position

Lightly applied position (a)

Fully applied position (c)

Not applied

Fully applied

Not applied

Fully applied

Speed Range: First

1.25 MPa (181 psi)

1.5 MPa (218 psi)

2.5 MPa (363psi)

3.0 MPa (435 psi)

Speed Range: Second

0.6 MPa (87 psi)

0.8 MPa (115 psi)

1.5 MPa (218 psi)

2.5 MPa (363psi)

T2-2-58

SECTION 2 SYSTEM Group 2 Control System

41 42

2 11

12 23

47 6

45 44

24 25

27 38

28 25

37 36

M A2

34 a b

OFF

c 33

16 17 18

13 9 21 19 20 30 22 32

31 TPD8-02-02-034

Brake Pedal Position: Lightly applied

12345678910-

11121314-

OFF

Brake Pedal Position: Fully applied

242526272829-

3031323334353637-

T2-2-59

38394041424344454647-

SECTION 2 SYSTEM Group 2 Control System Shift Holding Control Purpose: The shift holding control holds the current speed shift of transmission by operating the hold switch if necessary at automatic speed shift control. Operation: 1. Transmission Control Unit (TCU) (10) receives a signal from shift hold switch (12). 2. TCU(10) keeps transmission (13) engaged in the current speed range after shift hold switch (12) has been applied once. 3. With the shift hold control applied, the engaged transmission (13) speed range is held in that range, despite accelerator pedal (1) and brake pedal (40, 42) position changes.

fNOTE: The shift holding control is activated with

AUTO 1 mode (38) or AUTO 2 mode (36) selected by shift change mode switch (35).

4. When any of the items in the following under "Deactivation Conditions" exists, TCU(10) deactivates the shift hold control feature. Deactivation Conditions:  Key Switch (39): OFF  Shift Hold Switch (12): Operated once more  Downshift Switch (11): Operated  Forward/Reverse Lever (24) or Forward/Reverse Switch (28): Operated  Shift Switch (23): Operated  Shift Change Mode Switch (35): Operated  Pressure Sensor (Parking Brake) (31): Above specified pressure

fNOTE: Shift holding control is deactivated by the signal of forward/reverse switch (28) when it is in use on the machine.

T2-2-60

SECTION 2 SYSTEM Group 2 Control System

41 42

2 11

12 23

47 6

45 44

24 25

27 38

28 25

37 36

M A2

34 a b

OFF

c 33

16 17 18

13 9 21 19 20 30 22 32

31 TPD8-02-02-035

Brake Pedal Position: Lightly applied

12345678910-

11121314-

OFF

Brake Pedal Position: Fully applied

242526272829-

3031323334353637-

T2-2-61

38394041424344454647-

SECTION 2 SYSTEM Group 2 Control System (Blank)

T2-2-62

SECTION 2 SYSTEM Group 2 Control System Fan Control, Valve Control The fan control system and valve control consist of the following.  Fan Speed Control  Fan Reverse Rotation Control  Ride Control (Option)

T2-2-63

SECTION 2 SYSTEM Group 2 Control System Fan Speed Control Purpose: The fan speed control optimizes the fan speed depending on engine speed, engine coolant temperature, engine boost pressure, work mode selection, HVAC settings, torque converter oil temperature and hydraulic oil temperature. Operation: 1. The following items provide inputs to Main Controller (MC) (1) via Controller Area Network (CAN) communication (3).  Engine speed signal (crank revolution sensor (12), cam angle sensor (13)), from ECM (9)  Coolant temperature sensor (14) signal, from ECM (9)  Boost temperature sensor (11) signal, from ECM (9)  Outside temperature sensor (5), from HVAC controller (4)  Torque converter temperature sensor (17) signal, from TCU (15)  Power mode switch (35) signal  Hydraulic oil temperature sensor (37) signal  HVAC refrigerant pressure sensor (38) 2. MC (1) optimizes the signal sent to fan speed control solenoid valve (31) as adjusted by the input signals shown in the above listed items.

T2-2-64

SECTION 2 SYSTEM Group 2 Control System

37 36

7 2

19 3

20 4

21 9

11 12 13 14

23 17

33 28 31

32 26

TNEE-02-02-049 12345678910111213-

Main Controller (MC) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Outside Temperature Sensor Maintenance Pro (MP) Dr. Monitor Monitor Controller Engine Control Module (ECM) Engine Boost Temperature Sensor Crank Revolution Sensor Cam Angle Sensor

14- Coolant Temperature Sensor 15- Transmission Control Unit (TCU) 16- Transmission 17- Torque Converter Oil Temperature Sensor 18- Forward/Reverse Lever 19- Forward Position 20- Neutral Position 21- Reverse Position 22- Forward/Reverse Switch 23- Forward/Reverse Selector Switch

24- Parking Brake Solenoid Valve 25- Parking Brake Switch 26- Pressure Sensor (Parking Brake) 27- Fan Pump 28- Fan Motor 29- Fan Reverse Rotation Spool 30- Fan Reverse Rotation Control Solenoid Valve 31- Fan Speed Control Solenoid Valve 32- Fan Pump Delivery Pressure Sensor

T2-2-65

333435363738394041-

Fan Valve Fan Reversing Switch Power Mode Switch Key Switch Hydraulic Oil Temperature Sensor Pressure Sensor (Refrigerant Pressure) Accelerator Pedal Accelerator Pedal Sensor Intake-Air Temperature Sensor

SECTION 2 SYSTEM Group 2 Control System Fan Reverse Rotation Control Operation (MANUAL): 1. Main Controller (MC) (1) receives a signal from fan reversing switch (34).

Purpose: The fan reverse rotation control reverses the rotation of the cooling fan from the normal rotation direction by operating the fan reversing switch (34).

2. MC (1) activates fan reverse rotation control solenoid valve (30) and shifts fan reversing spool (29) when fan reversing switch (34) is set to manualreverse rotation position.

fNOTE: As the cooling fan direction is reversed, dust that has lodged in the radiator and oil cooler is discharged, helping to clear the cooling elements of blockage.

3. MC (1) receives the signals from key switch (36) and pressure sensor (parking brake) (26).

Operation (AUTO): 1. Main Controller (MC) (1) receives a signal from fan reversing switch (34).

4. MC (1) holds the fan in reverse rotation until key switch (36) is turned OFF when fan manual reversing switch (34) is set to OFF with the parking brake applied.

2. MC (1) activates fan reverse rotation control solenoid valve (30) and shifts fan reversing spool (29) when fan reversing switch (34) is set to autoreverse rotation position.

5. MC (1) rotates fan motor (28) in the normal direction after the fan has rotated in reverse rotation for one minute with the parking brake released.

3. Therefore, fan motor (28) rotates in reverse (suction direction).

fNOTE: The fan automatic reverse rotation can be set

4. MC (1) activates fan speed control solenoid valve (31) at the same time and fixes the fan rotation speed at 1300 min-1 (specified value).

with MPDr. (6) (option).

fNOTE: When the cooling fan rotation is changed, it

5. MC (1) performs the following operation when setting fan reversing switch (34) 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 time is 90 seconds when ambient temperature is low. 6. The fan speed control now optimizes the fan rotation speed depending on engine speed, engine coolant temperature, etc. (Refer to Fan Speed Control.) 7. When the fan reverse rotation control is deactivated by setting fan reversing switch (34) to OFF position, etc. the fan rotates only in normal direction until the fan reverse rotation control is activated again.

T2-2-66

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.

SECTION 2 SYSTEM Group 2 Control System

37 36

19 3

20 4

21 9

11 12 13 14

23 17

33 28 31

32 26

TNED-02-02-050 12345678910111213-

T2-2-67

3334353637-

Fan Valve Fan Reversing Switch Power Mode Switch Key Switch Hydraulic Oil Temperature Sensor 38- Pressure Sensor (Refrigerant Pressure) 39- Accelerator Pedal 40- Accelerator Pedal Sensor

SECTION 2 SYSTEM Group 2 Control System Ride Control (Option) 7. MC (1) alerts monitor controller (5) of the ride control operation status via CAN communication (3) as the changes are happening.

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.

8. Monitor controller (5) displays the ride control state on monitor (4).

fNOTE: The speed at which ride control engages and

Operation: 1. Transmission Control Unit (TCU) (10) receives a machine speed signal from machine speed sensor (12). TCU (10) sends a signals to Main Controller (MC) (1) via CAN communication (3).

disengages can be adjusted with monitor (4) and MPDr. (22). The setting range can be adjusted between 3 (1.9 mph) and 18 km/h (11 mph).

fNOTE: OFF or AUTO mode can be selected as with ride control switch (15).

2. MC (1) receives a signal from ride control switch (15).

fNOTE: When the following parts become defective, the ride control is deactivated.  Machine Speed Sensor (12)  Pump Delivery Pressure Sensor (13)  Lift Arm Angle Sensor (16)  Lift Arm Raise Pressure Sensor (17)

3. MC (1) energizes 2-spool solenoid valve unit (14) (SZ) and shifts ride control spool (19) in control valve (18) by pilot pressure when the machine reaches the speed to turn on ride control. 4. The base end of lift arm cylinder (21) opens to work against accumulator (20) to absorbs the fore and aft pitching shock cycles. The rod end of lift arm cylinder (21) will open to the tank circuit so that there is minimal latent vacuum at the rod side of the circuit. 5. Thus, hydraulic oil of lift arm cylinder (6) bottom side will flow to and from ride control accumulator (5). This will help smooth the machine ride by counteracting the machine bounce with a small am mount of lift arm motion. 6. MC (1) deactivates the ride control when machine speed falls below the point of ride control engagement. When any of the items shown below under the topic of "Temporary Deactivation Conditions" exists, MC (1) deactivates the ride control system to temporarily cease to operate. Temporary Deactivation Conditions:  Lift Arm Raise Operation (Pressure Sensor (Lift Arm Raise) (17)): Beyond specified pressure (Reference: 0.8 MPa, 8.2 kgf/cm2, 116 psi or more)  Pump Delivery Pressure Sensor (13): Beyond specified pressure (Reference: 18 MPa, 184 kgf/cm2, 2610 psi or more)

T2-2-68

SECTION 2 SYSTEM Group 2 Control System

22 17 16 4 5

2 15

10 1 3 6 8 9

20 14 21

TPD8-02-02-041

1234567-

Main Controller (MC) Column Display Controller Controller Area Network (CAN) Monitor Monitor Controller Engine Control Module (ECM) Engine

8- Crank Revolution Sensor 9- Cam Angle Sensor 10- Transmission Control Unit (TCU) 11- Transmission 12- Machine Speed Sensor 13- Pump Delivery Pressure Sensor

14151617-

Ride Control Solenoid Valve Ride Control Switch Lift Arm Angle Sensor Pressure Sensor (Lift Arm Raise) 18- Multiple Control Valve 19- Ride Control Spool

T2-2-69

20- Accumulator 21- Lift Arm Cylinder 22- Maintenance Pro (MP) Dr.

SECTION 2 SYSTEM Group 2 Control System (Blank)

T2-2-70

SECTION 2 SYSTEM Group 2 Control System Other Controls The other controls consist of the followings.  Transmission Alarm Control  Parking Brake Operation Indicator Control  Low Brake Oil Pressure Indicator Control  Low Steering Oil Pressure Indicator Control (Option)  Overrun Alarm Control  Lift Arm Auto Leveler Height Kickout Control  Lift Arm Auto Leveler Lower Kickout Control  Quick Power Mode Control  Auto Idling Stop Control  Secondary Steering Control (Option)

T2-2-71

SECTION 2 SYSTEM Group 2 Control System Transmission Alarm Control Purpose: The transmission alarm control illuminates the transmission warning indicator on the monitor control panel when there is a transmission fault. Operation: 1. TCU (8) receives the signals from each sensor of transmission (9). 2. When there is a transmission fault, Transmission Control Unit (TCU) (8) sends a signal to column display controller (2). 3. Transmission warning indicator (26) in the monitor control panel illuminates in response to the signal from column display controller (2).

T2-2-72

SECTION 2 SYSTEM Group 2 Control System

24 26 27 28 29

30 1

3 6

11 12 13

17 18 TNED-02-02-036 123456789-

Main Controller (MC) Column Display Controller Air Conditioner Controller Monitor Monitor Controller Engine Control Module (ECM) Engine Transmission Control Unit (TCU) Transmission

10- Torque Converter Input Speed Sensor 11- Torque Converter Output Speed Sensor 12- Transmission Intermediate Shaft Speed Sensor 13- Machine Speed Sensor 14- Forward/Reverse Lever 15- Forward/Reverse Switch 16- Parking Brake Solenoid Valve

17- Pressure Sensor (Parking Brake) 18- Parking Brake Switch 19- Pressure Sensor (Brake Primary Pressure) 20- Steering Pressure Switch 21- Brake Pedal (Left) 22- Pressure Sensor (Brake Secondary Pressure) 23- Brake Pedal (Right) 24- Brake Pedal (Right) Switch

T2-2-73

25- Alarm 26- Transmission Warning Indicator 27- Parking Brake Indicator 28- Low Brake Oil Pressure Indicator 29- Low Steering Oil Pressure Indicator 30- Controller Area Network (CAN)

SECTION 2 SYSTEM Group 2 Control System Parking Brake Operation Indicator Control Purpose: The parking brake operation indicator control illuminates the parking brake indicator on the monitor control panel when the parking brake is applied. Operation: 1. When the parking brake is applied while parking the machine, Main Controller (MC) (1) receives a signal from pressure sensor (parking brake) (17). 2. Parking brake switch (18) ON signal energizes parking brake solenoid valve (16) that permits the pressurized oil in parking brake (31) to the hydraulic tank. Parking brake (31) is applied with spring force, securing the machine in position. 3. When the pressure inside parking brake actuator (31) circuit is below the specified level (8.0 MPa, 82 kgf/cm2, 1160 psi or less) that would release parking brake actuator (31), pressure sensor (17) indicates this pressure via a signal that is sent to MC (1). MC (1) confirms that the park brake is applied via a signal sent to column display controller (2). 4. Column display controller (2) lights illuminates parking brake indicator (27).

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SECTION 2 SYSTEM Group 2 Control System

24 26 27 28 29

30 1

3 6

11 12 13

16 31 17 18 TNED-02-02-037 123456789-

Main Controller (MC) Column Display Controller Air Conditioner Controller Monitor Monitor Controller Engine Control Module (ECM) Engine Transmission Control Unit (TCU) Transmission

17- Pressure Sensor (Parking Brake) 18- Parking Brake Switch 19- Pressure Sensor (Brake Primary Pressure) 20- Steering Pressure Switch (Option) 21- Brake Pedal (Left) 22- Pressure Sensor (Brake Secondary Pressure) 23- Brake Pedal (Right)

T2-2-75

24- Brake Pedal (Right) Switch 25- Alarm 26- Transmission Warning Indicator 27- Parking Brake Indicator 28- Brake Oil Low Pressure Indicator 29- Low Steering Oil Pressure Indicator (Option) 30- Controller Area Network (CAN) 31- Parking Brake

SECTION 2 SYSTEM Group 2 Control System Brake Oil Low Pressure Indicator Control Purpose: Main Controller (MC) (1) sends a signal to column display controller (2) to illuminate the low oil brake pressure indicator on the monitor control panel when the service brake pressure circuit falls below a safe level. Operation: 1. MC (1) receives the signal from pressure sensor (brake primary pressure) (19). 2. When the service brake pressure circuit is below 8.1 MPa (83 kgf/cm2, 1175 psi or less), at primary brake pressure sensor (19), MC (1) sends OFF signal to column display controller (2) in 0.8 seconds. 3. Column display controller (2) illuminates low brake oil pressure indicator (28). 4. When the service brake pressure circuit is well above 10.0 MPa (102 kgf/cm2, 1450 psi or more) at primary brake pressure sensor (19), MC (1) sends ON signal to column display controller (2). 5. Column display controller (2) turns OFF low brake oil pressure indicator (28).

fNOTE: When pressure sensor (brake primary pressure) (19) malfunctions, low brake oil pressure indicator (28) illuminates and remains ON.

T2-2-76

SECTION 2 SYSTEM Group 2 Control System

24 26 27 28 29

30 1

3 6

11 12 13

17 18 TNED-02-02-038 12345678-

Main Controller (MC) Column Display Controller Air Conditioner Controller Monitor Monitor Controller Engine Control Module (ECM) Engine Transmission Control Unit (TCU) 9- Transmission 10- Torque Converter Input Speed Sensor

11- Torque Converter Output Speed Sensor 12- Transmission Intermediate Shaft Speed Sensor 13- Machine Speed Sensor 14- Forward/Reverse Lever 15- Forward/Reverse Switch 16- Parking Brake Solenoid Valve 17- Pressure Sensor (Parking Brake) 18- Parking Brake Switch 19- Pressure Sensor (Brake Primary Pressure)

20- Steering Pressure Switch (Option) 21- Brake Pedal (Left) 22- Pressure Sensor (Brake Secondary Pressure) 23- Brake Pedal (Right) 24- Brake Pedal (Right) Switch 25- Alarm 26- Transmission Warning Indicator 27- Parking Brake Indicator 28- Low Brake Oil Pressure Indicator

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29- Low Steering Oil Pressure Indicator (Option) 30- Controller Area Network (CAN) (Option)

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 (20): 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 (29). 3. MC (1) also engages the secondary steering system (option), if equipped, as determined by operating conditions. (Refer to Secondary Steering Control.)

fNOTE: Steering pressure switch (20) is not equipped without the secondary steering system option. This control does not exist and low steering oil pressure indicator (29) keeps OFF.

T2-2-78

SECTION 2 SYSTEM Group 2 Control System

24 26 27 28 29

30 1

3 6

11 12 13

17 18 TNED-02-02-039 123456789-

Main Controller (MC) Column Display Controller Air Conditioner Controller Monitor Monitor Controller Engine Control Module (ECM) Engine Transmission Control Unit (TCU) Transmission

T2-2-79

25- Alarm 26- Transmission Warning Indicator 27- Parking Brake Indicator 28- Low Brake Oil Pressure Indicator 29- Low Steering Oil Pressure Indicator 30- Controller Area Network (CAN)

SECTION 2 SYSTEM Group 2 Control System Overrun Alarm Control Purpose: The overrun alarm control sounds the alarm and give warning to the operator of excessive machine speed, to warn the operator to slow down so as not to damage the transmission. Operation: 1. Transmission Control Unit (TCU) (8) receives the machine ground speed signal from machine speed sensor (13). TCU (8) sends signals to Main Controller (MC) (1) via Controller Area Network (CAN) communication (30). 2. MC (1) sends a signal to column display controller (2) via CAN communication (30) when the machine speed exceeds the specified safe level. 3. When this occurs, column display controller (2) sounds alarm (25) inside the cab. 4. Alarm (25) inside the cab stops sounding when the machine speed returns to a safe speed.

fNOTE: The machine speed of the overrun alarm control with 20.5 inch tires is 44 k/h (27 mph) or more.

T2-2-80

SECTION 2 SYSTEM Group 2 Control System

24 26 27 28 29

30 1

3 6

11 12 13

17 18 TNED-02-02-040 123456789-

Main Controller (MC) Column Display Controller Air Conditioner Controller Monitor Monitor Controller Engine Control Module (ECM) Engine Transmission Control Unit (TCU) Transmission

T2-2-81

25- Alarm 26- Transmission Warning Indicator 27- Parking Brake Indicator 28- Low Brake Oil Pressure Indicator 29- Low Steering Oil Pressure Indicator 30- Controller Area Network (CAN)

SECTION 2 SYSTEM Group 2 Control System Lift Arm Auto Leveler Height Kickout Control 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. (Refer to SECTION 4 OPERATIONAL PERFORMANCE TEST.) Operation: 1. The lift arm height kickout control position is able to be viewed on the setting screen of dual lift arm auto leveler - height kickout, which is memorized in MC (1).

6. MC (1) determines the stopping position of the lift arm (pre-selected by the operator), and judges the stop position according to the signal from the lift arm angle sensor (12) when the lift arm is located in the stop position. 7. MC (1) deenergizes lift arm lowering 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.

fNOTE: When lift arm angle sensor (12) malfunctions, the lift arm auto leveler height kickout control will no longer function.

2. Adjust the lift arm height kickout control to the required level and select the height kickout ON to make this feature effective.

3. MC (1) receives a signal from lift arm angle sensor (12).

4. MC (1) energizes lift arm raising coil (6) of pilot valve (5) as the lift arm is raised/and the detent function is applied at the control lever. 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.

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-

T2-2-82

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

13 12 10

2 8

4 11

5 6

TNED-02-02-044

1234-

Main Controller (MC) Monitor Monitor Controller Controller Area Network (CAN)

5678-

Pilot Valve Lift Arm Raising Coil Lift Arm Lowering Coil Control Valve

9101112-

T2-2-83

Lift Arm Spool Lift Arm Cylinder Bucket Cylinder Lift Arm Angle Sensor

13- Column Display Controller

SECTION 2 SYSTEM Group 2 Control System Lift Arm Auto Leveler Lower Kickout Control 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.

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. (Refer to SECTION 4 OPERATIONAL PERFORMANCE TEST.) Operation: 1. The lift arm lower kickout control position is able to be viewed on the setting screen of dual lift arm auto leveler - lower kickout, which is memorized in MC (1).

7. After 1.5 seconds, MC (1) stops exciting the lift arm lower side coil (7) of 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 lower position. Then, the lift arm stops.

fNOTE: When lift arm angle sensor (12) malfunctions, the lift arm auto leveler lower kickout control will no longer function.

2. Adjust the lift arm lower kickout control to the required level and select the lower kickout ON to make this feature effective. 3. MC (1) receives a signal from lift arm angle sensor (12). 4. MC (1) energizes lift arm lowering coil (7) of pilot valve (5) as the lift arm is lowered/and the detent function is applied at the control lever. 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.

B C

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.

TNED-02-02-043

AB-

T2-2-84

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

13 12

2 8 3

C-4

C-3 5 6

9 TPD8-02-02-045

1234-

Main Controller (MC) Monitor Monitor Controller Controller Area Network (CAN)

5678-

Pilot Valve Lift Arm Raising Coil Lift Arm Lowering Coil Control Valve

9101112-

T2-2-85

Lift Arm Spool Lift Arm Cylinder Bucket Cylinder Lift Arm Angle Sensor

13- Column Display Controller

SECTION 2 SYSTEM Group 2 Control System Quick Power Mode Control Purpose: Applying the quick P (power) mode switch temporarily changes the work mode to the power mode for greater power with the power mode switch OFF (E mode). This provides better digging power and greater breakout force.

5. MC (1) sends the power mode status signal to monitor controller (5) via CAN communication (3) as the changes are happening. 6. Monitor controller (5) displays the power mode status on monitor (4).

Operation: 1. Main Controller (MC) (1) receives signals from power mode switch (28) and quick power switch (27). 2. When MC (1) receives input signal from quick power switch (27), the power mode is activated. 3. The power mode remains activated until the quick P mode switch (27) is released. (Quick P mode applies the normal Power mode function.) 4. When any of the following items listed under the topic below of "Deactivation Conditions" exists, MC (1) deactivates the quick P mode control. Deactivation Conditions:  Quick Power Switch (27): Pushed once more  Speed-shift up during automatic speed shift  Selected speed shift and torque converter rotation speed ratio: Specified value (Reference: 0.8) or more  Forward/Reverse Lever (16): Operated or Neutral Position (18)  Power Mode Switch (28): Changed

fNOTE: Quick P mode control is deactivated by the

signal of forward/reverse switch (20) when it is in use on the machine.

T2-2-86

SECTION 2 SYSTEM Group 2 Control System

4 2

16 17

18 19 10

20 17

31 M

21 28 8 9

11 23

24 25 26 TNED-02-02-048 12345678910-

Main Controller (MC) Column Display Controller Controller Area Network (CAN) Monitor Monitor Controller Engine Control Module (ECM) Engine Crank Revolution Sensor Cam Angle Sensor Transmission Control Unit (TCU)

11- Transmission 12- Torque Converter Input Speed Sensor 13- Torque Converter Output Speed Sensor 14- Machine Speed Sensor 15- Shift Switch 16- Forward/Reverse Lever 17- Forward Position 18- Neutral Position 19- Reverse Position

20- Forward/Reverse Switch 21- Forward/Reverse Selector Switch 22- Pump Delivery Pressure Sensor 23- Torque Control Solenoid Valve 24- Parking Brake Solenoid Valve 25- Pressure Sensor (Parking Brake) 26- Parking Brake Switch 27- Quick Power Switch 28- Power Mode Selector Switch

T2-2-87

293031323334-

Travel Mode Selector Switch AUTO 2 Mode Manual Mode AUTO 1 Mode Accelerator Pedal Accelerator Pedal Sensor

SECTION 2 SYSTEM Group 2 Control System Auto Idling Stop Control 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. Operation: 1. When all of the following items under the topic of "Conditions" exist, MC (3) sends the auto idling stop signal to monitor controller (9) via Controller Area Network (CAN) communication (5).

fNOTE: The auto idling stop control can be adjusted or turned ON/OFF with monitor (8) and MPDr. (7).

fNOTE: After it shuts down, return key switch (40) to the

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

fNOTE: Auto idling stop control is activated by the signal

 Auto Idling Stop setting: ON  Accelerator Pedal (1): Not depressed  Parking Brake: Engaged  Brake Pedals (44, 46): Not depressed (Reference: Pressure Sensor (Brake Secondary Pressure) (45): 0.16 MPa (1.6 kgf/cm2, 23 psi) or less)  Forward/Reverse Lever (23) or Forward/Reverse Switch (27): Neutral Position (25)  Front Attachment, Steering: Not operated (Reference: Pump Delivery Pressure Sensor (29): 5.0 MPa (51 kgf/ cm2, 725 psi) or less  Coolant Temperature Sensor (15): 100 °C (212 °F) or less  Hydraulic Oil Temperature Sensor (41): 100 °C (212 °F) or less  Torque Converter Oil Temperature Sensor (18): 110 °C (230 °F) or less  Aftertreatment Device Manual Regeneration Control: Not performed  Abnormal communication of ECM (10) or Column Display Controller (4): None  Except for transmission learning  Engine Speed: 600 RPM (min-1) or more 2. Monitor controller (9) displays the auto idling stop notice on monitor (8) and column display controller (4) sounds buzzer (48) via CAN communication (5) once 30 seconds before the auto idling stop engages.

fNOTE: The time for auto idling stop is adjustable by settings within monitor (8).

fNOTE: Column display controller (4) sounds buzzer (48)

with an intermittent sound at 15 seconds and another sound at 5 seconds to alert the operator of engine shut down. 3. MC (3) turns ON auto idling stop relay (43) when the auto idling stop time is up. 4. Then, the battery relay is turned OFF and the engine stops. (Refer to SYSTEM / Electrical System.)

T2-2-88

of forward/reverse switch (27) when it is in use on the machine.

SECTION 2 SYSTEM Group 2 Control System

45 46

7 22 48 8

42 41

23 24

25 40

26 16

27 24

38 M

5 6

28 12 13 14 15

35 34

17 30

43 31 32 33 TNED-02-02-046 123456789101112131415-

27- Forward/Reverse Switch 28- Forward/Reverse Selector Switch 29- Pump Delivery Pressure Sensor 30- Torque Control Solenoid Valve 31- Parking Brake Solenoid Valve 32- Pressure Sensor (Parking Brake) 33- Parking Brake Switch 34- Exhaust Filter Switch 35- Power Mode Selector Switch 36- Travel Mode Selector Switch 37- AUTO 2 Mode 38- Manual Mode 39- AUTO 1 Mode

T2-2-89

40- Key Switch 41- Hydraulic Oil Temperature Sensor 42- Pressure Sensor (Primary Pilot Pressure) 43- Auto Idling Stop Relay 44- Brake Pedal (Left) 45- Pressure Sensor (Brake Secondary Pressure) 46- Brake Pedal (Right) 47- Brake Pedal (Right) Switch 48- Buzzer

SECTION 2 SYSTEM Group 2 Control System Secondary Steering Control (Option)

fNOTE: When secondary steering pump delivery

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.

pressure sensor (16) malfunctions, monitor controller (4) flashes the emergency indicator at monitor panel (3).

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 (16).

Normal operation: 1. MC (1) receives a signal from steering pressure switch (15). (Refer to Low Steering Oil Pressure Indicator Control.) 2. Transmission Control Unit (TCU) (10) receives a signal from machine speed sensor (12). TCU (10) sends a signal to MC (1) via CAN communication (5).

2. 3 seconds after the engine starts, MC (1) automatically turns secondary steering pump relay (19) ON for a maximum of 5 seconds.

3. If the steering cannot be operated, MC (1) activates secondary steering motor (20) to turn and operates secondary steering pump (21) 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 (15) turns OFF).

3. Secondary steering motor (20), and then secondary steering pump (21) operate for a maximum of 2 seconds. 4. MC (1) turns secondary steering pump relay (19) 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 (21) operating.

4. Pressurized oil from secondary steering pump (21) 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 monitor controller (4) via CAN communication (5).

5. When secondary steering pump relay (19) is ON, monitor controller (4) indicates that it is operating on monitor (3). 6. Monitor controller (4) secondary steering indicator flashes to indicate that the secondary steering pump delivery pressure is below 4.7 MPa (48 kgf/ cm2, 681) psi or less (abnormal pressure) while secondary steering pump (21) is in operation.

6. Monitor controller (4) indicates that the secondary steering is operating via the indicator in monitor (3).

fNOTE: The secondary steering control can be adjusted

IMPORTANT: Large amount of electricity is required to operate secondary steering pump (21). Check the pump manually using the secondary steering operation check switch (option). Refer to Operation and Maintenance Manual for this check switch.

T2-2-90

or turned ON/OFF with monitor (3).

SECTION 2 SYSTEM Group 2 Control System

3 15

14 10 1 5

8 9

a 16

TNED-02-02-047 a-

To Steering Valve

1234567-

Main Controller (MC) Column Display Controller Monitor Monitor Controller Controller Area Network (CAN) Engine Control Module (ECM) Engine

8- Cam Angle Sensor 9- Crank Revolution Sensor 10- Transmission Control Unit (TCU) 11- Transmission 12- Machine Speed Sensor 13- Pump Delivery Pressure Sensor

14- Secondary Steering Check Switch 15- Steering Pressure Switch 16- Secondary Steering Pump Delivery Pressure Sensor 17- Accelerator Pedal 18- Accelerator Pedal Sensor

T2-2-91

19- Secondary Steering Pump Relay 20- Secondary Steering Motor 21- Secondary Steering Pump

SECTION 2 SYSTEM Group 2 Control System (Blank)

T2-2-92

SECTION 2 SYSTEM Group 2 Control System Control by Electrical and Hydraulic Combined Circuit The combined electric and hydraulic control circuits have the following controls.  Bucket Auto Leveler Control  Lift Arm Float Control

T2-2-93

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. 2. 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). 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. Therefore, 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 multiple control valve (7). 4. Pressurized oil from main pump (10) flows to bucket cylinder (1) through bucket spool (9) in multiple 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 and the bucket control lever returns to the neutral position. 6. Therefore, when bucket spool (9) in multiple control valve (7) returns to the neutral position, bucket cylinder (1) stops. 7. This automatically permits the bucket to be leveled.

T2-2-94

SECTION 2 SYSTEM Group 2 Control System

4 9 7 5

TNDB-02-02-060

8 a-

From Fuse Box B (Fuse #16)

123-

Bucket Cylinder Bucket Proximity Switch Bar

45-

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

6789-

T2-2-95

Pilot Pump Multiple Control Valve Lift Arm Spool Bucket Spool

10- Main Pump 11- Hydraulic 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 float position (farther position than the lift arm lowering position), Main Controller (MC) (12) turns ON, and electromagnet (2) on the lift arm lowering side is turned ON by current (a) from fuse #16 in fuse box B. 2. Therefore, the lift arm control lever is held by electromagnet (2) on the lift arm lowering side. 3. Pressurized oil from pilot valve (3) moves lift arm spool (8) in control valve (7) to the float position (farthest down position). 4. Pressurized oil from main pump (10) is blocked by lift arm spool (8). Pressurized oil from lift arm cylinder (1) is routed to hydraulic oil tank (11) through lift arm spool (8). 5. 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. 6. The lift arm control lever returns to the neutral position when it is pulled more strongly than the magnetic force of electromagnet (2) on the lift arm lowering side. 7. Therefore, lift arm spool (8) in control valve (7) returns to the neutral position and the lift arm float control is deactivated.

T2-2-96

SECTION 2 SYSTEM Group 2 Control System

a 2 9

3 7 12

TNDB-02-02-061

From Fuse Box B (Fuse #16)

12-

Lift Arm Cylinder Electromagnet on Lift Arm Lowering Side

36-

Pilot Valve (Lift Arm Control Lever) Pilot Pump

789-

T2-2-97

Multiple Control Valve Lift Arm Spool Bucket Spool

10- Main Pump 11- Hydraulic Oil Tank 12- MC

SECTION 2 SYSTEM Group 2 Control System (Blank)

T2-2-98

SECTION 2 SYSTEM Group 3 Engine System Outline The engine system is broadly divided into the Engine Control Module (ECM) system and urea Selective Catalytic Reduction (SCR) system.  ECM System The ECM receives the signals from the sensors and MC. The ECM processes and activates the two-way valve, suction control valve, and EGR motor in order to control the supply pump, injector, and EGR valve. The supply pump is activated by the engine and produces high-pressure fuel. The common rail distributes high-pressure fuel produced by the supply pump to the injector in each engine cylinder. The injector injects high-pressure fuel from the common rail.  Urea SCR System The ECM receives the signals from the sensors. The ECM processes and activates the DEF supply module and dosing module, injects the DEF into the engine exhaust gas, converts NOx into nitrogen and water, and reduces NOx. When any of the following condition exist, the engine output restriction control is performed.  Insufficient DEF Level  Malfunction of Urea SCR System

T2-3-1

SECTION 2 SYSTEM Group 3 Engine System ECM System The ECM system consists of the followings.  Fuel Injection Control  Fuel Injection Amount Correction Control  EGR Control  Preheating Control  Variable Turbocharger Control  Alarm Control

T2-3-2

SECTION 2 SYSTEM Group 3 Engine System (Blank)

T2-3-3

SECTION 2 SYSTEM Group 3 Engine System Fuel Injection Control ECM (15) detects the engine running condition according to the signals from each sensor and MC (24). ECM (15) controls the fuel injection amount, injection pressure, injection timing, and injection rate according to the engine running condition. The fuel injection control consists of the followings.  Fuel Injection Volume Control  Fuel Injection Timing Control  Fuel Injection Rate Control  Fuel Injection Pressure Control

T2-3-4

SECTION 2 SYSTEM Group 3 Engine System

4 8 14

9 10

26 11 12 25 23 15

27 18

28 29 35

32 20 34

21 33 TNEK-02-03-008

12-

3456789-

EGR Gas Differential Pressure Sensor Temperature Barometric Atmospheric Pressure (TBAP) Sensor Boost Pressure/Boost Temperature Sensor Exhaust Pressure Sensor Crank Revolution Sensor Cam Angle Sensor Coolant Temperature Sensor Crankcase Pressure Sensor Engine Oil Pressure Switch

1011121314151617181920-

Coolant Level Sensor EGR Motor Position Sensor EGR Motor EGR Gas Temperature Sensor Turbocharger Speed Sensor Engine Control Module (ECM) Two-Way Valve Injector Common Rail Pressure Sensor Common Rail Supply Pump

21- Fuel Tank 22- Suction Control Valve 23- Controller Area Network (CAN) 24- Main Controller (MC) 25- Variable Geometry Turbo (VGT) Controller 26- VGT Actuator 27- Diesel Oxidation Catalyst (DOC) 28- Dosing Module 29- Selective Catalytic Reduction (SCR) 30- DEF Sensor Unit

T2-3-5

31- DEF Tank 32- DEF Pressure Sensor 33- DEF Supply Module Temperature Sensor 34- DEF Supply Module 35- Coolant Control Valve

SECTION 2 SYSTEM Group 3 Engine System Fuel Injection Volume Control Purpose: The fuel injection volume control provides the best fuel injection rate. Operation: 1. Engine Control Module (ECM) (15) reads the engine speed signals from crank revolution sensor (5) and cam angle sensor (6). 2. Main Controller (MC) (24) receives signals from the accelerator pedal sensor, various sensors and switches, and the Transmission Control Unit (TCU), and calculates and sends signals to ECM (15) to adjust the target speed as needed for the present operation. (Refer to SYSTEM / Control System.) 3. ECM (15) controls the fuel injection volume by turning two-way valve (16) in injector (17) ON or OFF according to the engine speed and the signals from MC (24).

T2-3-6

SECTION 2 SYSTEM Group 3 Engine System

4 8 14

9 10

26 11 12 25 23 15

27 18

28 29 35

32 20 34

21 33 TNEK-02-03-020

12-

3456789-

1011121314151617181920-

2122232425262728293031-

T2-3-7

Fuel Tank Suction Control Valve CAN MC Variable Geometry Turbo (VGT) Controller VGT Actuator Diesel Oxidation Catalyst (DOC) Dosing Module Selective Catalytic Reduction (SCR) DEF Sensor Unit DEF Tank

32- DEF Pressure Sensor 33- DEF Supply Module Temperature Sensor 34- DEF Supply Module 35- Coolant Control Valve

SECTION 2 SYSTEM Group 3 Engine System Fuel Injection Timing Control

Operation of Fuel Injection

Purpose: The fuel injection timing control calculates the best fuel injection timing.

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

Operation: 1. The Engine Control Module (ECM) calculates the fuel injection timing according to the engine speed and fuel injection volume. 2. The ECM turns two-way valve (2) in the injector ON/ OFF according to fuel injection timing.

Fuel Injection Rate Control

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.

Purpose: The fuel injection rate control controls the fuel injection timing and fuel injection amount, and improves combustion in the engine cylinder. 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. The 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 Engine System 1. Two-way valve: ON

2. Injection Start 1

1 9

8 7

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 Engine System Fuel Injection Pressure Control Purpose: The fuel injection pressure control provides the best fuel injection pressure. Operation: 1. Engine Control Module (ECM) (15) calculates the required fuel injection volume according to the engine speed signal and signals from MC (24). (Refer to Fuel Injection Volume Control.) 2. Common rail pressure sensor (18) sends the signals according to the pressure in common rail (19) to ECM (15). 3. ECM (15) calculates the best fuel pressure for common rail (19) from the engine speed, fuel injection volume, and common rail pressure sensor (18) signal. 4. ECM (15) sends a signal to suction control valve (22) in supply pump (20) and supplies fuel at the rate of optimum pressure and volume within common rail (19). 5. Pressurized fuel in common rail (19) is supplied to injector (17), and this controls the fuel injection pressure.

T2-3-10

SECTION 2 SYSTEM Group 3 Engine System

4 8 14

9 10

26 11 12 25 23 15

27 18

28 29 35

32 20 34

21 33 TNEK-02-03-021

12-

3456789-

1011121314151617181920-

T2-3-11

31- DEF Tank 32- DEF Pressure Sensor 33- DEF Supply Module Temperature Sensor 34- DEF Supply Module 35- Coolant Control Valve

SECTION 2 SYSTEM Group 3 Engine 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) (15) corrects the fuel injection amount volume. (Start up correction) 2. ECM (15) also compensates the fuel injection volume according to signals from Temperature Barometric Atmospheric Pressure (TBAP) sensor (2). (High altitude correction) 3. ECM (15) sends a signal to the injection solenoid coil at two-way valve (16) in injector (17) and optimizes the best fuel injection volume.

T2-3-12

SECTION 2 SYSTEM Group 3 Engine System

4 8 14

9 10

26 11 12 25 23 15

27 18

28 29 35

32 20 34

21 33 TNEK-02-03-022

12-

3456789-

10111213141516171819202122-

23- Controller Area Network (CAN) 24- Main Controller (MC) 25- Variable Geometry Turbo (VGT) Controller 26- VGT Actuator 27- Diesel Oxidation Catalyst (DOC) 28- Dosing Module 29- Selective Catalytic Reduction (SCR) 30- DEF Sensor Unit 31- DEF Tank 32- DEF Pressure Sensor

T2-3-13

33- DEF Supply Module Temperature Sensor 34- DEF Supply Module 35- Coolant Control Valve

SECTION 2 SYSTEM Group 3 Engine 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: TBAP (Temperature Barometric Atmospheric

Operation:  EGR Gas Volume Control 1. ECM (13) determines the EGR gas volume according to engine RPM's (min-1), fuel flow rate, boost temperature, coolant temperature, atmospheric pressure, EGR gas differential pressure, and intakeair 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 actuator motor position sensor (9). It maintains the opening gap at the required position, depending on the operational requirements.  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.

T2-3-14

Pressure) sensor (15) detects the temperature and pressure of intake-air.

SECTION 2 SYSTEM Group 3 Engine System

5 6 4 7

8 12 9 11

14 15

21 20

19 18 17

TNEE-02-03-007

1234567-

From Air Cleaner To Intercooler Exhaust (To Aftertreatment Device) Engine Outlet of Coolant Cooling System Inlet of Coolant

891011-

EGR Valve EGR Motor Position Sensor EGR Motor Intake-Air (From Suction Intercooler) 12- Intake Manifold 13- Engine Control Module (ECM)

14- EGR Gas Differential Pressure Sensor 15- Temperature Barometric Atmospheric Pressure (TBAP) Sensor 16- Boost Pressure/Boost Temperature Sensor

T2-3-15

17- Common Rail Pressure Sensor 18- Coolant Temperature Sensor 19- Cam Angle Sensor 20- Crank Revolution Sensor 21- EGR Gas Temperature Sensor

SECTION 2 SYSTEM Group 3 Engine System Preheating Control Purpose: The cylinder preheat system adjusts length of currentcarrying time in intake air heater (4) according to the temperature in the intake manifold to stabilize engine idle after start up.

Operation: 1. The boost pressure/ boost temperature sensor (1) sends the signal according to the temperature in the intake manifold to Engine Control Module (ECM) (2).

2. ECM (2) controls intake air heater relay (3) energizing time period according to signal.

3. Thus the length of time that intake air heater relay (3) heats intake air heater (4) is controlled.

TNEK-02-03-023

12-

T2-3-16

Boost Pressure/Boost Temperature Sensor ECM

345-

Intake Air Heater Relay Intake Air Heater From Battery Relay

SECTION 2 SYSTEM Group 3 Engine System Variable Turbocharger Control Purpose: The variable turbocharger control 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 turbo charger compressor is changed and the intake air pressure is regulated as required for the engine. This results in intake air efficiently for a wide variety of engine speeds.

T2-3-17

SECTION 2 SYSTEM Group 3 Engine System Alarm Control Operation: 1. Engine Control Module (ECM) (5) receives the signals from the engine oil pressure switch (3), boost temperature sensor (2), and coolant temperature sensor (4). 2. ECM (5) sends the signals to monitor controller (7) according to the signals from each sensor via Controller Area Network (CAN) (6). 3. Monitor controller (7) sends the digital signal to column display controller (8). 4. Column display controller (8) turns ON each indicator. At the same time, each alarm is displayed on monitor (1).  Engine Warning Alarm  Overheat Alarm  Engine Oil Pressure Alarm

2 3 4 6 5

TDC2-02-03-015 123-

Monitor Boost Temperature Sensor Engine Oil Pressure Switch

45-

Coolant Temperature Sensor Engine Control Module (ECM)

67-

T2-3-18

Controller Area Network (CAN) Monitor Controller

Column Display Controller

SECTION 2 SYSTEM Group 3 Engine System Urea SCR System The urea SCR system injects the DEF into the exhaust of engine (1) to convert NOx into nitrogen and water. Therefore, the urea SCR system reduces NOx from exhaust gas. ECM (24) controls the urea SCR system. ECM (24) drives DEF supply module (20) and dosing module (22) according to the signals from the sensors, and controls the following functions.

DEF supply module (20) pumps the DEF from DEF tank (14) to dosing module (22). Dosing module (22) injects the DEF according to the signal from ECM (24).

 DEF Injection Control  Start-Up Control  DEF Defrosting Control  DEF Thermal Control  After-Run Control

2 35

6 4

8 9

1 22

10 12

18 21 25

26 27

123456-

Engine DOC (Diesel Oxidation Catalyst) DOC Inlet Exhaust Temperature Sensor DOC Outlet Exhaust Temperature Sensor NOx Sensor (DOC Inlet) SCR Catalyst

78910111213-

20 30

17 16 15

TNEK-02-03-002

SCR Inlet Exhaust Temperature Sensor SCR Outlet Exhaust Temperature Sensor NOx Sensor (SCR Outlet) CAN3 DEF Piping Sensor Board DEF Sensor Unit

141516171819-

DEF Tank DEF Tank Level Sensor DEF Tank Temperature Sensor DEF Quality Sensor DEF Pressure Sensor DEF Supply Module Temperature Sensor 20- DEF Supply Module 21- Coolant Control Valve

T2-3-19

2224252627282930-

Dosing Module ECM Monitor Controller MC CAN1 Coolant Piping TBAP Sensor Reverting Valve

SECTION 2 SYSTEM Group 3 Engine System DEF Injection Control Purpose: The DEF injection control controls the optimum injection amount of DEF. Operation: 1. NOx sensors (5, 9) detect the concentration of NOx in exhaust emission. 2. Sensor board (12) sends the signals from NOx sensors (5, 9) to ECM (24) by using CAN3 (10). 3. TBAP sensor (29) detects the intake-air flow rate from the air cleaner. 4. ECM (24) receives the signal from TBAP sensor (29). 5. ECM (24) controls the dosing module (22) and optimizes the DEF injection amount according to each signal.

T2-3-20

SECTION 2 SYSTEM Group 3 Engine System

6 9

3 5

1 22

18 13

30 17 16 15

26 27

29 TNEK-02-03-003

123456-

Engine DOC (Diesel Oxidation Catalyst) DOC Inlet Exhaust Temperature Sensor DOC Outlet Exhaust Temperature Sensor NOx Sensor (DOC Inlet) SCR Catalyst

78910111213-

SCR Inlet Exhaust Temperature Sensor SCR Outlet Exhaust Temperature Sensor NOx Sensor (SCR Outlet) CAN3 DEF Piping Sensor Board DEF Sensor Unit

141516171819-

DEF Tank DEF Tank Level Sensor DEF Tank Temperature Sensor DEF Quality Sensor DEF Pressure Sensor DEF Supply Module Temperature Sensor 20- DEF Supply Module 21- Coolant Control Valve

T2-3-21

2224252627282930-

Dosing Module ECM Monitor Controller MC CAN1 Coolant Piping TBAP Sensor Reverting Valve

SECTION 2 SYSTEM Group 3 Engine System Start-Up Control Purpose: The start-up control increases the pressure of DEF for injection. Operation: 1. The SCR inlet exhaust temperature sensor (7) detects the inlet temperature of SCR catalyst (6). 2. ECM (24) activates DEF supply module (20) when the inlet temperature of SCR catalyst (6) becomes the specified value or higher. 3. DEF supply module (20) supplies the pressurized DEF to dosing module (22).

T2-3-22

SECTION 2 SYSTEM Group 3 Engine System

6 9

3 5

1 22

18 13

30 17 16 15

26 27

29 TNEK-02-03-004

123456-

Engine DOC (Diesel Oxidation Catalyst) DOC Inlet Exhaust Temperature Sensor DOC Outlet Exhaust Temperature Sensor NOx Sensor (DOC Inlet) SCR Catalyst

78910111213-

SCR Inlet Exhaust Temperature Sensor SCR Outlet Exhaust Temperature Sensor NOx Sensor (SCR Outlet) CAN3 DEF Piping Sensor Board DEF Sensor Unit

141516171819-

DEF Tank DEF Tank Level Sensor DEF Tank Temperature Sensor DEF Quality Sensor DEF Pressure Sensor DEF Supply Module Temperature Sensor 20- DEF Supply Module 21- Coolant Control Valve

T2-3-23

2224252627282930-

Dosing Module ECM Monitor Controller MC CAN1 Coolant Piping TBAP Sensor Reverting Valve

SECTION 2 SYSTEM Group 3 Engine System DEF Defrosting Control Purpose: The DEF defrosing control circulates the coolant and defrosts the DEF when the DEF may freeze. Operation: 1. When the DEF or intake-air temperature is low, ECM (24) opens coolant control valve (21). 2. Heated coolant from engine (1) flows to DEF tank (14) through coolant control valve (21) and DEF supply module (20). 3. Coolant is circulated and the DEF is defrosted. 4. ECM (24) closes coolant control valve (21) when the specified time has passed.

T2-3-24

SECTION 2 SYSTEM Group 3 Engine System

6 9

3 5

1 22

18 13

30 17 16 15

26 27

29 TNEK-02-03-005

123456-

Engine DOC (Diesel Oxidation Catalyst) DOC Inlet Exhaust Temperature Sensor DOC Outlet Exhaust Temperature Sensor NOx Sensor (DOC Inlet) SCR Catalyst

78910111213-

SCR Inlet Exhaust Temperature Sensor SCR Outlet Exhaust Temperature Sensor NOx Sensor (SCR Outlet) CAN3 DEF Piping Sensor Board DEF Sensor Unit

141516171819-

DEF Tank DEF Tank Level Sensor DEF Tank Temperature Sensor DEF Quality Sensor DEF Pressure Sensor DEF Supply Module Temperature Sensor 20- DEF Supply Module 21- Coolant Control Valve

T2-3-25

2224252627282930-

Dosing Module ECM Monitor Controller MC CAN1 Coolant Piping TBAP Sensor Reverting Valve

SECTION 2 SYSTEM Group 3 Engine System DEF Thermal Control Purpose: The DEF thermal control circulates coolant and defrosts the DEF when the DEF or intake-air temperature is below the specified value. Operation: 1. When DEF or intake-air temperature is below the specified value, ECM (24) opens coolant control valve (21). 2. Heated coolant from engine (1) flows to DEF tank (14) through coolant control valve (21) and DEF supply module (20). 3. By this means, coolant is circulated and DEF is kept warm. 4. When DEF and intake-air temperature become the specified value or higher, ECM (24) closes coolant control valve (21).

T2-3-26

SECTION 2 SYSTEM Group 3 Engine System

6 9

3 5

1 22

18 13

30 17 16 15

26 27

29 TNEK-02-03-006

123456-

Engine DOC (Diesel Oxidation Catalyst) DOC Inlet Exhaust Temperature Sensor DOC Outlet Exhaust Temperature Sensor NOx Sensor (DOC Inlet) SCR Catalyst

78910111213-

SCR Inlet Exhaust Temperature Sensor SCR Outlet Exhaust Temperature Sensor NOx Sensor (SCR Outlet) CAN3 DEF Piping Sensor Board DEF Sensor Unit

141516171819-

DEF Tank DEF Tank Level Sensor DEF Tank Temperature Sensor DEF Quality Sensor DEF Pressure Sensor DEF Supply Module Temperature Sensor 20- DEF Supply Module 21- Coolant Control Valve

T2-3-27

2224252627282930-

Dosing Module ECM Monitor Controller MC CAN1 Coolant Piping TBAP Sensor Reverting Valve

SECTION 2 SYSTEM Group 3 Engine System After-Run Control Purpose: The after-run control returns the DEF from DEF piping (11) to DEF tank (14) when the key switch is set to the OFF position. This prevents DEF from freezing and crystallization in the piping. Operation: 1. When the key switch is set to the OFF position, ECM (24) turns ON reverting valve (30) and the flow direction of the DEF is changed. 2. DEF supply module (20) returns DEF from DEF piping (11) to DEF tank (14). 3. ECM (24) turns OFF DEF supply module (20) when the specified time has passed. 4. Then, ECM (24) is turned OFF.

T2-3-28

SECTION 2 SYSTEM Group 3 Engine System

6 9

3 5

1 22

18 13

30 17 16 15

26 27

29 TNEK-02-03-007

123456-

Engine DOC (Diesel Oxidation Catalyst) DOC Inlet Exhaust Temperature Sensor DOC Outlet Exhaust Temperature Sensor NOx Sensor (DOC Inlet) SCR Catalyst

78910111213-

SCR Inlet Exhaust Temperature Sensor SCR Outlet Exhaust Temperature Sensor NOx Sensor (SCR Outlet) CAN3 DEF Piping Sensor Board DEF Sensor Unit

141516171819-

DEF Tank DEF Tank Level Sensor DEF Tank Temperature Sensor DEF Quality Sensor DEF Pressure Sensor DEF Supply Module Temperature Sensor 20- DEF Supply Module 21- Coolant Control Valve

T2-3-29

2224252627282930-

Dosing Module ECM Monitor Controller MC CAN1 Coolant Piping TBAP Sensor Reverting Valve

SECTION 2 SYSTEM Group 3 Engine System Engine Output Restriction Control (INDUCEMENT) Purpose: When DEF level becomes low, or malfunction occurs on the urea SCR system, the engine output restriction control displays the alarm on the monitor and sounds the buzzer. When the machine is continuously operated under this state, the engine output restriction control gradually decreases the engine torque and speed. Operation: 1. Signals from the urea SCR system are sent to ECM (15) by using CAN communication (23). 2. When any of the following condition is met, ECM (15) decreases the engine torque. Conditions:  DEF Level: 5 % or lower  Urea SCR System: Abnormal, and a certain period of time has passed  Parts influenced with NOx emission: Abnormal, and the specified time has passed (Basically, the limit is the same as the urea SCR system) 3. In addition, ECM (15) decreases the engine torque and sets the engine speed to the slow idle position according to the level of DEF and the elapsed time from the system error occurrence. 4. When the machine recovers to the normal condition, ECM (15) controls the engine torque and speed according to the other engine controls.

T2-3-30

SECTION 2 SYSTEM Group 3 Engine System

4 8 14

9 10

26 11 12 25 23 15

27 18

28 29 35

19 32 20 34

21 33 TNEK-02-03-009

12345678-

EGR Gas Differential Pressure Sensor TBAP Sensor Boost Pressure/Boost Temperature Sensor Exhaust Pressure Sensor Crank Revolution Sensor Cam Angle Sensor Coolant Temperature Sensor Crankcase Pressure Sensor

9101112131415161718-

Engine Oil Pressure Switch Coolant Level Sensor EGR Motor Position Sensor EGR Motor EGR Gas Temperature Sensor Turbocharger Speed Sensor ECM Two-Way Valve Injector Common Rail Pressure Sensor

192021222324252627-

T2-3-31

Common Rail Supply Pump Fuel Tank Suction Control Valve CAN MC VGS Controller VGS Actuator DOC (Diesel Oxidation Catalyst)

282930313233-

Dosing Module SCR Catalyst DEF Sensor Unit DEF Tank DEF Pressure Sensor DEF Supply Module Temperature Sensor 34- DEF Supply Module 35- Coolant Control Valve

SECTION 2 SYSTEM Group 3 Engine System Insufficient DEF Level 1. When the DEF level becomes 10 % or lower, the engine output restriction control level is set to the step 1. 2. An alarm is displayed on the monitor and the buzzer sounds once. 3. Then, the engine output restriction control level is set to the step 2 to step 5 depending on the remaining level of the DEF.

T2-3-32

SECTION 2 SYSTEM Group 3 Engine System Engine Output Restriction Control Level

DEF Level

Engine Torque

Engine Speed

Urea Alarm

Buzzer

Step 1 Warning 1

10 % or lower

No restriction

Indicator is ON.

Sounds once

Monitor Screen

TNEK-02-03-010

Step 2 Warning 2

5 % or lower Restriction

Sounds every 2.4 seconds. Indicator (Sounds for blinks 1.2 seconds slowly. and stops for 1.2 seconds. Repeats them.)

No restriction

TNEK-02-03-011

Step 3 Initial

2.5 % or lower

Restriction

Sounds every 0.6 seconds. Indicator (Sounds for blinks 0.3 seconds slowly. and stops for 0.3 seconds. Repeats them.) TNEK-02-03-012

Step 4 Secondary

Restriction

Indicator blinks fast.

Sounds every 0.6 seconds.

TNEK-02-03-013

Step 5 Final

30 minutes after starting 0%

No restriction

Slow Idle

Indicator blinks fast.

Sounds every 0.6 seconds.

TNEK-02-03-014

T2-3-33

SECTION 2 SYSTEM Group 3 Engine System Malfunction of Urea SCR System 1. When malfunction occurs (first time) on the urea SCR system, the engine output restriction control level is set to the step 1. 2. An alarm is displayed on the monitor and the buzzer sounds once. 3. Then, the engine output restriction control level is set to the step 2 or step 5 according to the elapsed time. 4. When malfunction of the urea SCR system occurs, the ECM monitors the system condition for 40 hours after the recovery. 5. When malfunction occurs (second time) during this 40 hours after the recovery, transitional period is shortened from malfunction (first time) for the engine output restriction control level.

T2-3-34

SECTION 2 SYSTEM Group 3 Engine System Engine Output Restriction Control Level

Malfunction of the urea SCR system

Engine Torque

Engine Speed

Urea Alarm

Step 1 Warning 1

(Restriction starts.)

No restriction

Indicator Sounds once is ON.

Buzzer

Monitor Screen

TNEK-02-03-015

Step 2 Warning 2

2 hours after starting the step 1

Restriction

No restriction

Sounds every 2.4 seconds. (Sounds for Indicator 1.2 seconds blinks and stops for slowly. 1.2 seconds. Repeats them.) TNEK-02-03-016

Step 3 Initial

30 minutes after starting the step 2

Restriction

Sounds every 0.6 seconds. (Sounds for Indicator 0.3 seconds blinks and stops for slowly. 0.3 seconds. Repeats them.) TNEK-02-03-017

Step 4 Secondary

75 minutes after starting the step 3

Restriction

Indicator Sounds every blinks 0.6 seconds. fast.

TNEK-02-03-017

Step 5 Final

15 minutes after starting the step 4

No restriction

Slow Idle

Indicator Sounds every blinks 0.6 seconds. fast.

TNEK-02-03-018

T2-3-35

SECTION 2 SYSTEM Group 3 Engine System Aftertreatment Device NOx sensor (DOC inlet) (9) detects the concentration of NOx at upstream of diesel oxidation catalyst (DOC) 1 (8). NOx sensor (SCR outlet) (6) detects the concentration of NOx at downstream of diesel oxidation catalyst (DOC) 2 (4). Dosing module (11) injects DEF into aftertreatment device (1). The SCR inlet exhaust temperature sensor (2) detects the exhaust temperature at upstream of SCR catalyst (3). The SCR outlet exhaust temperature sensor (4) detects the exhaust temperature at downstream of diesel oxidation catalyst (DOC) 2 (4).

Aftertreatment device (1) consists of the diesel oxidation catalyst (DOC) block and SCR catalyst block. Aftertreatment device (1) converts NOx in exhaust gas into nitrogen and water by a chemical reaction of NOx and DEF. Thus NOx is reduced from exhaust gas. The DOC inlet exhaust temperature sensor (10) detects the exhaust temperature at upstream of diesel oxidation catalyst (DOC) 1 (8). The DOC outlet exhaust temperature sensor (7) detects the exhaust temperature at downstream of diesel oxidation catalyst (DOC) 1 (8).

2 3 4

5 6

11 10 1 7

8 9

Front Side of Machine

12-

Aftertreatment Device SCR Inlet Exhaust Temperature Sensor SCR Catalyst

456-

TNEK-02-03-001

Diesel Oxidation Catalyst (DOC) 2 SCR Outlet Exhaust Temperature Sensor NOx Sensor (SCR Outlet)

789-

T2-3-36

DOC Outlet Exhaust Temperature Sensor Diesel Oxidation Catalyst (DOC) 1 NOx Sensor (DOC Inlet)

10- DOC Inlet Exhaust Temperature Sensor 11- Dosing Module

SECTION 2 SYSTEM Group 3 Engine System Operation 1. Exhaust gas which burns in the engine cylinder flows into aftertreatment device (1).

6. SCR catalyst 1 (3) initiates a chemical reaction of ammonia (NH3) and NOx in exhaust gas, so that, NOx is broken down into nitrogen and water.

2. Diesel oxidation catalyst (DOC) 1 (8) reduces harmful substances contained in exhaust gas such as carbon monoxide by initiating a chemical reaction.

7. Diesel oxidation catalyst (DOC) 2 (4) breaks down ammonia (NH3) into nitrogen (N2) and water (H2O). 8. As a result, NOx is reduced from exhaust gas and any remaining ammonia (NH3) is removed.

3. ECM (11) controls dosing module (11) according to the signals from NOx sensor (DOC inlet) (9). 4. Dosing module (11) injects the DEF into aftertreatment device (1). 5. At this time, DEF breaks down into ammonia (NH3) and carbon dioxide (CO2).

9 10 12

7 12 11 TNEK-02-03-019

123-

Aftertreatment Device SCR Inlet Exhaust Temperature Sensor SCR Catalyst

456-

Diesel Oxidation Catalyst (DOC) 2 SCR Outlet Exhaust Temperature Sensor NOx Sensor (SCR Outlet)

789-

T2-3-37

DOC Outlet Exhaust Temperature Sensor Diesel Oxidation Catalyst (DOC) 1 NOx Sensor (DOC Inlet)

10- DOC Inlet Exhaust Temperature Sensor 11- ECM 12- CAN3

SECTION 2 SYSTEM Group 3 Engine System Aftertreatment Device Regeneration Control Purpose: The after treatment device regeneration control mixes unburnt fuel with exhaust gas, and initiates oxidation of unburnt fuel by using the diesel oxidation catalysts (DOC). This process increases exhaust gas temperature and performs regeneration.  NH3 Reset: NH3 reset resets error between actual value and calculated value of NH3 adsorbed to the SCR catalyst.  Elimination of HC Poisoning: When activity of the diesel oxidation catalysts (DOC) is low in a cold weather, NH3 adsorption to the SCR catalyst may be blocked due to unburnt fuel (HC). Elimination of HC poisoning is performed by increasing the exhaust temperature.  Removal of white deposition: When the machine is operated with low exhaust temperature for long period of time, part of injected DEF may creates white deposition. White deposition is removed by increasing the exhaust temperature.  Elimination of Sulfur Poisoning: When sulfur compound contained in fuel adhere to the diesel oxidation catalysts (DOC), the catalyst performance deteriorates. Elimination of Sulfur poisoning is performed by increasing the exhaust temperature.

Operation: 1. ECM (13) injects fuel (post injection (14)) to exhaust gas which burns in engine cylinder (18), and exhaust gas mixed with unburnt fuel is supplied to diesel oxidation catalyst (DOC) 1 (8). 2. Diesel oxidation catalyst (DOC) 1 (8) oxidizes unburnt fuel and raises exhaust temperature. 3. Therefore, the exhaust temperature of the outlet of diesel oxidation catalyst (DOC) 1 (8) raises up to about 560 to 580 °C and regeneration is carried out. Auto Regeneration:  The regeneration is automatically carried out when the specified time has passed after the previous regeneration. Manual Regeneration:  When Manual Regeneration Request is displayed on the monitor, the regeneration is manually carried out by not operating the accelerator pedal (setting the engine speed at slow idle speed), applying the parking brake, setting the forward/reverse lever to the neutral position, setting the control lever lock switch to the lock position, and turning ON the regeneration switch.

T2-3-38

SECTION 2 SYSTEM Group 3 Engine System

9 10

7 12 13 TNEK-02-03-019

TDC2-02-03-018

15 a-

Fuel Injection Amount

12-

Aftertreatment Device SCR Inlet Exhaust Temperature Sensor SCR Catalyst Diesel Oxidation Catalyst (DOC) 2

34-

5678-

SCR Outlet Exhaust Temperature Sensor NOx Sensor (SCR Outlet) DOC Outlet Exhaust Temperature Sensor Diesel Oxidation Catalyst (DOC) 1

9- NOx Sensor (DOC Inlet) 10- DOC Inlet Exhaust Temperature Sensor 11- Dosing Module 12- CAN3 13- ECM 14- Post Injection

T2-3-39

15161718-

Multi Injection Pilot Injection Main Injection Cylinder

SECTION 2 SYSTEM Group 3 Engine System (Blank)

T2-3-40

SECTION 2 SYSTEM Group 4 Hydraulic System Outline Hydraulic system is broadly divided into the pilot circuit, main circuit, fan circuit, and secondary steering circuit (option). Pilot Circuit: Power Source Pilot Pump

Oil Control Method Brake Charge Valve (Unloader Valve) Manifold Valve Pump Regulator Ride Control Valve

Supplied to Charging Circuit Service Brake Circuit Parking Brake Circuit Lift Arm/Bucket Operation Control Circuit Pump Control Circuit Ride Control Circuit

Oil Control Method Steering Pilot Valve Control Valve

Supplied to Steering Cylinder Lift Arm/Bucket Cylinder

Oil Control Method Fan Valve

Supplied to Fan Motor

Main Circuit: Power Source Main Pump Priority Valve Fan Circuit: Power Source Fan Pump

Secondary Steering Circuit (Option): Power Source Secondary Steering Pump

Oil Control Method Steering Pilot Valve

Supplied to Steering Cylinder

T2-4-1

SECTION 2 SYSTEM Group 4 Hydraulic System Pilot Circuit Outline: Pressurized oil from pilot pump (16) is used in order to operate the following circuits.  Charging Circuit (21)  Service Brake Circuit (32)  Parking Brake Circuit (28)  Lift Arm/Bucket Operation Control Circuit (5)  Pump Control Circuit (25)  Ride Control Circuit (13)

T2-4-2

SECTION 2 SYSTEM Group 4 Hydraulic System 5

4 11

6 7 8 9 10

21 22 24

14 26

28 15

30 29 18

32 16

17 TNDB-02-04-004

12345678-

Bucket Pilot Valve Lift Arm Pilot Valve Auxiliary 1 Pilot Valve (Option) Auxiliary 2 Pilot Valve (Option) Lift Arm/Bucket Operation Control Circuit Auxiliary 3 Spool (Option) Auxiliary 2 Spool (Option) Auxiliary 1 Spool (Option)

91011121314151617-

Bucket Spool Lift Arm Spool Control Valve Ride Control Valve Ride Control Circuit Hydraulic Tank Suction Filter Pilot Pump Pilot Filter

18- Priority Valve (Brake) 19- Brake Charge Valve (Unloader Valve) 20- Manifold Valve 21- Charging Circuit 22- Control Lever Lock Solenoid Valve 23- Torque Control Solenoid Valve 24- Regulator

T2-4-3

2526272829303132-

Pump Control Circuit Parking Brake Solenoid Valve Parking Brake Parking Brake Circuit Brake Valve Front Brake Rear Brake Service Brake Circuit

SECTION 2 SYSTEM Group 4 Hydraulic System Charging Circuit (Brake Priority Circuit) 7. Brake charge valve (unloader valve) (2) shifts brake priority valve (1) according to the pressure amount charged in service brake accumulators (5, 6).

Purpose: The charging circuit supplies pressurized oil from pilot pump (10) to service brake circuits (A, B) through brake charge valve (unloader valve) (2) preferentially and maintains the brake performance.

8. Excess oil from service brake accumulators (5, 6) is supplied to manifold valve (12) via brake priority valve (1).

fNOTE: Charging circuit (18) consists of brake charge

valve (unloader valve) (2) and manifold valve (12). (Refer to COMPONENT OPERATION / Charging Block.)

9. Manifold valve (12) supplies the pilot pressure oil in order to operate the following circuits.  Lift Arm / Bucket Operation Control Circuit  Pump Control Circuit  Ride Control Circuit (Option)

 Outline 1. Pressurized oil from pilot pump (10) is supplied to brake charge valve (unloader valve) (2).

10. Torque control solenoid valve (14) supplies pilot pressure oil to the pump control circuit (X1). (Refer to Pump Control Circuit.)

2. Priority valve (brake) (1) supplies pressurized oil from pilot pump (10) to service brake circuits (A, B) with priority to the brake circuits.

11. Loading pilot accumulator (16) is charged with pressurized pilot oil to keep a constant supply of pilot pressure oil available for loading circuit application.

3. Shuttle valve (4) controls the oil flow so that the pressure of service brake accumulators (5, 6) (front and rear) are equal by sensing their pressure difference. 4. Charge relief valve (7) controls the oil flow so that service brake accumulators (5, 6) (front and rear) are charged with pressurized oil for brake circuits. 5. At the same time, pressurized oil is supplied to parking brake circuit (c) in order to release the parking brake. (Refer to Parking Brake Circuit.) 6. Charge relief valve (7) prevents pressure inside brake charge valve (unloader valve) (2) from increasing over the set pressure. Pilot relief valve (13) prevents pressure inside manifold valve (12) from increasing over the set pressure.

T2-4-4

12. Front loader control lever lock solenoid valve (17) is energized by the front loader control lever lock switch and supplies pilot pressure oil to operate the loading control circuits. (Refer to Lift Arm / Bucket Operation Control Circuit.)

SECTION 2 SYSTEM Group 4 Hydraulic System

4 3

9 1

10 11 PS2

14 15

PP1 16

TNDB-02-04-005

ABc-

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

PS2- To Ride Control Circuit PP1- To Lift Arm/Bucket Operation Control Circuit

X1- To Pump Control Circuit

12-

Priority Valve (Brake) Brake Charge Valve (Unloader Valve) Orifice Shuttle Valve

91011121314-

34-

678-

Service Brake Accumulator (Front) Service Brake Accumulator (Rear) Charge Relief Valve Check Valve

T2-4-5

Orifice Pilot Pump Hydraulic Tank Manifold Valve Pilot Relief Valve Torque Control Solenoid Valve

15- Check Valve 16- Pilot Accumulator (Front Attachment) 17- Control Lever Lock Solenoid Valve 18- Charging Circuit

SECTION 2 SYSTEM Group 4 Hydraulic System  When the service brake is not applied 1. Brake priority valve (1) in brake charge valve (unloader valve) (2) has moved right due to the spring force.

10. Therefore, the pressure at the left side (spring side) of brake priority valve (1) decreases.

2. Pressurized oil from pilot pump (10) is supplied to shuttle valve (4) through brake priority valve (1) and check valve (8).

11. When the pressure at the left side (spring side) of brake priority valve (1) and the spring force become lower than the pressure at the right side of brake priority valve (1), brake priority valve (1) moves left.

3. Shuttle valve (4) shifts according to the pressure of service brake accumulators (5, 6) (front and rear).

12. Consequently, more pilot pressure oil is supplied to manifold valve (12) through brake priority valve (1).

4. Service brake accumulators (5, 6) (front and rear) are charged with accumulator pressurized oil from shuttle valve (4) so that the pressure is the same in each accumulator. 5. Pilot pressure oil is supplied to service brake circuits (A, B) in order to apply the brake. 6. In addition, pilot pressure oil is supplied to brake priority valve (1) and charge relief valve (7) through orifice (3) to operate brake priority valve (1). 7. When service brake is not operated, the oil pressure in service brake accumulators (5, 6) (front and rear) increases. 8. When the circuit pressure in brake charge valve (unloader valve) (2) increases over the specified value (reaches the cutout pressure), charge relief valve (7) shifts downward and lowers the pressure in the circuit to the left of brake priority valve (1). 9. This permits the excess pressure to be sent to hydraulic tank (11) through charge relief valve (7).

T2-4-6

SECTION 2 SYSTEM Group 4 Hydraulic System

4 3

9 1

10 11 PS2 14

PP1 16

TNDB-02-04-030

ABc-

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

PS2- To Ride Control Circuit PP1- To Lift Arm/Bucket Operation Control Circuit

X1- To Pump Control Circuit

12-

Priority Valve (Brake) Brake Charge Valve (Unloader Valve) Orifice Shuttle Valve

91011121314-

34-

678-

Service Brake Accumulator (Front) Service Brake Accumulator (Rear) Charge Relief Valve Check Valve

T2-4-7

Orifice Pilot Pump Hydraulic Tank Manifold Valve Pilot Relief Valve Torque Control Solenoid Valve

15- Check Valve 16- Pilot Accumulator (Front Attachment) 17- Control Lever Lock Solenoid Valve 18- Charging Circuit

SECTION 2 SYSTEM Group 4 Hydraulic System  When the service brake is applied 1. When the brake is applied repeatedly the accumulator oil pressure (5, 6) (front and rear) decreases. When it decreases below the specified level, the circuit pressure in brake charge valve (unloader valve) (2) decreases. 2. When the circuit pressure in brake charge valve (unloader valve) (2) decreases (reaches the cut-in pressure), charge relief valve (7) moves upward. 3. Pressurized oil to operate brake priority valve (1) is blocked by charge relief valve (7). 4. Therefore, the pressure at the left side (spring side) of brake priority valve (1) increases. 5. When the pressure at the left side (spring side) of brake priority valve (1) and increases, along with the combined spring force inside this valve, brake priority valve spool (1) moves to the right. 6. Consequently, brake circuit supply pressurized oil is sent to service brake accumulators (5, 6) (front and rear) through brake priority valve (1). 7. Brake charge valve (unloader valve) (2) supplies pressurized oil from pilot pump (10) to service brake circuits (A, B) by priority according to the pressure amount charged in service brake accumulators (5, 6) to keep a ready supply of accumulated brake oil pressure for brake application.

fNOTE: Brake priority valve (1) supplies the excess

amount of pressurized oil in the brake circuit to manifold valve (12) by the spring force.

Its operation assures that the brake system receives oil first, so the brake system will always be operable when any other function of the machine is also operable.

T2-4-8

SECTION 2 SYSTEM Group 4 Hydraulic System

4 3

9 1

10 11 PS2 14

PP1 16

TNDB-02-04-031

ABc-

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

PS2- To Ride Control Circuit PP1- To Lift Arm/Bucket Operation Control Circuit

X1- To Pump Control Circuit

12-

Priority Valve (Brake) Brake Charge Valve (Unloader Valve) Orifice Shuttle Valve

91011121314-

34-

678-

Service Brake Accumulator (Front) Service Brake Accumulator (Rear) Charge Relief Valve Check Valve

T2-4-9

Orifice Pilot Pump Hydraulic Tank Manifold Valve Pilot Relief Valve Torque Control Solenoid Valve

15- Check Valve 16- Pilot Accumulator (Front Attachment) 17- Control Lever Lock Solenoid Valve 18- Charging Circuit

SECTION 2 SYSTEM Group 4 Hydraulic System Service Brake Circuit Purpose: The service brake circuit controls the front and rear brakes according to the stroke of the brake pedal.  When the service brake is applied 1. Pressurized oil from the pilot pump is supplied to brake valve (22) through the brake charge valve (unloader valve) to apply the brake. (Refer to Brake Priority Circuit.)

 When the service brake is released 1. The brake circuit oil (A, B) from the brake charge valve (unloader valve) is blocked by brake spools (25, 26) on top and bottom of brake valve (22).

2. Brake spools (25, 26) on top and bottom of brake valve (22) are connected by spring (24) and move according to brake pedal (c) application angle.

2. When brake pedal (c) is not applied, brake operating pressurized oil (A, B) returns to hydraulic tank (11) through front / rear brakes (21, 20) and brake spools (25, 26) on top and bottom of brake valve (22). 3. Therefore, front / rear brakes (21, 20) are released.

3. Brake circuit oil (A, B) is supplied to front / rear brakes (21, 20) according to brake pedal (c) application angle. 4. Therefore, front / rear brakes (21, 20) are applied. 5. Brake oil circuit pressures (A, B) flow through both of orifices (23) in brake valve (22) and push back spool (25, 26). 6. This blocks the circuit between the brake charge valve (unloader valve) and brake valve (22). The pressure in the brake output circuit is maintained, and the oil pressure in proportion to the brake pedal application angle is output. 7. Brake oil circuit pressure (A, B) is applied to both front and rear brake circuits (21, 20) at the same time and both front and rear brake circuits operate simultaneously.

fNOTE: Front / rear brake units (21, 20) are housed in the front / rear axles. (Refer to COMPONENT OPERATION / Axle.)

T2-4-10

SECTION 2 SYSTEM Group 4 Hydraulic System  When brake is applied 20

c 21

22 25 A 24 23 26

 When brake is released

23 TNED-02-04-020

c 21

22 25 A

24 23 26

11 A-

From Brake Charge Valve (Unloader Valve) (Front Brake Operating Pressurized Oil)

20- Rear Brake 21- Front Brake

B-

From Brake Charge Valve (Unloader Valve) (Rear Brake Operating Pressurized Oil)

22- Brake Valve 23- Orifice

TNED-02-04-018

Brake Pedal

24- Spool 25- Brake Spool (Top)

T2-4-11

26- Brake Spool (Bottom)

SECTION 2 SYSTEM Group 4 Hydraulic System Parking Brake Circuit Purpose: The parking brake circuit controls the parking brake.  Outline: 1. Pressurized oil from pilot pump (10) is supplied to the parking brake circuit through the charge valve to release the parking brake. 2. Parking brake release oil flows through check valve (4) and pressure is stored in parking brake accumulator (3). Parking brake oil flows to parking brake solenoid valve (5). 3. Parking brake solenoid valve (5) is energized or deenergized by operating parking brake switch (c) and applies or releases parking brake (1). 4. Check valve (4) prevents reverse flow of parking brake oil.  When parking brake is applied: 1. When parking brake switch (c) is turned ON (this deenergizes the circuit), parking brake solenoid valve (5) is moved to the left by the spring. 2. Parking brake oil returns to hydraulic tank (11) through parking brake solenoid valve (5). 3. Therefore, parking brake (1) is applied by the spring force.  When parking brake is released: 1. Parking brake solenoid valve (5) is moved to the right when parking brake switch (c) is turned OFF (this energizes the circuit). 2. Parking brake oil flows through parking brake solenoid valve (5) to parking brake (1). 3. Therefore, parking brake (1) is released as spring (2) is compressed.

fNOTE: The parking brake is a spring apply, hydraulic release (SAHR) type brake unit, and releases when pressure is applied to it.

T2-4-12

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

 When parking brake is released

1 a

TNED-02-04-008

Parking brake is released

Parking brake is applied

12-

Parking Brake Spring

34-

Parking Brake Accumulator Check Valve

5- Parking Brake Solenoid Valve 10- Pilot Pump

T2-4-13

Parking Brake Switch Signal 11- Hydraulic Tank

SECTION 2 SYSTEM Group 4 Hydraulic System Lift Arm/Bucket Operation Control Circuit Purpose: The lift arm/bucket operation control circuit controls the lift arm and bucket. NOTE: Refer to COMPONENT OPERATION / Pilot Valve and Control Valve.

 Outline: 1. Front control lever lock solenoid valve (17) moves to the right when front control lever lock switch (a) is set to the OFF position. 2. Pressurized oil (P2) from the pilot pump is supplied to pilot valve (1) through loading control lever lock solenoid valve (17). 3. Pilot valve (1) supplies the pilot pressure oil according to the operation of lift arm control lever (2) and bucket control lever (3) as oil is provided to control valve (7). 4. Lift arm spool (18) and bucket spool (20) in control valve (7) are shifted by pressurized oil to operate the lift arm / bucket. 5. Pressurized oil from main pump (14) moves the right and left lift arm cylinders (8, 9), and bucket cylinder (19) by shifting lift arm spool (18) and bucket spool (20). 6. The lift arm and bucket are operated by the right and left lift arm cylinders (8, 9), and bucket cylinder (19). (Refer to Main Circuit.)

T2-4-14

7. Flow regulator valve (4) is provided between pilot valve (1) and control valve (7). Flow regulator valve (4) is consist of dampening valve (5) and restriction valve (6). 8. When stopping the lift arm raise / lower operation, dampening valve (5) reduces the volume of the returning pilot oil from control valve (7). Consequently lift arm spool (18) quick movement is dampened so as not to suddenly come to a stop and shock the machine with inertia energy caused from a sudden stop. (Refer to Shock Damping Function When Stopping Lift Arm Raise / Lower Operation.) 9. When stopping bucket dump operation, restriction valve (6) reduce the returning pilot oil from control valve (7). Consequently, bucket spool (20) quick movement is dampened so as not to suddenly come to a stop and shock the machine with inertia energy caused from a sudden stop.

SECTION 2 SYSTEM Group 4 Hydraulic System

2 8

11 5

6 7 21

12 13

18 P2

20 15 a

16 TPD8-02-04-001

P2- From Brake Charge Valve (Unloader Valve) (Pilot 123456-

Pilot Valve Lift Arm Control Lever Bucket Control Lever Flow Regulator Valve Shockless Valve Restriction Valve

789111213-

Pressure Oil)

Control Valve Lift Arm Cylinder (Left) Lift Arm Cylinder (Right) Hydraulic Tank Manifold Valve Pilot Relief Valve

14- Main Pump 15- Check Valve 16- Pilot Accumulator (Front Attachment) 17- Front Control Lever Lock Solenoid Valve

T2-4-15

From Front Control Lever Lock Switch (OFF Signal) 18192021-

Lift Arm Spool Bucket Cylinder Bucket Spool Orifice

SECTION 2 SYSTEM Group 4 Hydraulic System  Shock Dampening Function When Stopping Lift Arm Raise / Lower Operation

fNOTE: When lowering the lift arm, the items mentioned below take place. 1. The lift arm spool returns to the neutral position when releasing the lift arm raise lever.

2. Returning oil (Pia2) from lift arm spool flows through the lift arm raise circuit and orifice (21) of flow regulator valve (4). 3. Therefore, the pressure difference is generated at front and back of orifice (21) and dampening valve (5) moves to the left. 4. Returning oil (Pia2) from lift arm spool flows through dampening valve (5) and decreases the pressure. 5. Consequently, the quick movement of lift arm spool is dampened and the inertia shock that would have occurred due to the sudden stop of the lift arm is reduced.

fNOTE: Shock dampening valve (5) buffers the return oil through port Pib2, and modulates to lift arm stop when lowering.

T2-4-16

SECTION 2 SYSTEM Group 4 Hydraulic System

11 5 5 4

6 21

PP1

Pia1

Pib1 TPD8-02-04-002

PP1- From Manifold Valve (Pilot Pressure Oil)

Pia1- From Lift Arm Raise Circuit (Pilot Pressure Oil)

Pib1- From Lift Arm Lower Circuit (Pilot Pressure Oil)

12-

34-

56-

Pilot Valve Lift Arm Control Lever

Bucket Control Lever Flow Regulator Valve

T2-4-17

Dampering Valve Restriction Valve

11- Hydraulic Tank 21- Orifice

SECTION 2 SYSTEM Group 4 Hydraulic System Pump Control Circuit  Control by Pump Control Pressure from Pump Control Valve (Refer to COMPONENT OPERATION/Pump Device.)  When the control lever is in the neutral position: 1. When the control lever is in neutral, pressurized oil from main pump (8) flows back to hydraulic tank (5) through neutral circuit (11) in control valve (3) and orifice (10).

 Control by Pilot Pressure from Torque Control Solenoid Valve (Refer to Control System/Pump Control.) 1. Pilot pressure oil P2 from the brake charge valve (unloader valve) acts on the torque control solenoid valve (14).

2. Pressure difference between upstream pressure Pc1 and downstream pressure Pc2 of orifice (10) acts on pump regulator (7) as the pump control pressure. 3. When the flow rate of pressurized oil which flows back to hydraulic tank (5) through neutral circuit (11) increases, the pressure difference is increased by orifice (10), and the pump control pressure is increased. 4. Therefore, regulator (7) decreases the pump delivery flow rate. 5. When the pressure difference is increased by orifice (10) and reaches the specified level pressure, the surge pressure relief valve (4) is opened. Pressurized oil flows back to hydraulic tank (5) through orifice (10) and the surge pressure relief valve (4). Therefore, the occurrence of surge pressure in neutral circuit (11) is prevented.  When the control lever is operated 1. As pressurized oil from main pump (8) flows to spools (15, 16), the flow rate flowing through neutral circuit (11) is decreased. 2. Therefore, as the pressure difference is decreaced by orifice (10) decreases, the pump control pressure is decreased. 3. Therefore, regulator (7) increases the pump delivery flow rate.

T2-4-18

2. Pilot pressure X1 (torque control pressure ST) according to the signal from MC acts on regulator (7) in main pump (8) through the torque control solenoid valve (14). 3. As pilot pressure X1 acts on regulator (7), the pump delivery flow rate is decreased according to the pressure.

SECTION 2 SYSTEM Group 4 Hydraulic System

P2 Pc1 Pc2

5 7

5 TPD8-02-04-008

P2- Pilot Pressure Oil from Brake Charge Valve (Unloader Valve)

X1- Torque Control Pressure Pc1- Pump Control Pressure

Pc2- Pump Control Pressure

3456-

781011-

12141516-

Control Valve Surge Pressure Relief Valve Hydraulic Tank Pump Device

Regulator Main Pump Orifice Neutral Circuit

fNOTE: The illustration shows the oil flow when the control lever is in the neutral position.

T2-4-19

Manifold Valve Torque Control Solenoid Valve Lift Arm Spool Bucket Spool

17- Low-Pressure Relief Valve

SECTION 2 SYSTEM Group 4 Hydraulic System Ride Control Circuit (Option) Purpose: When driving the machine, the ride control circuit supplies the pressurized oil of the lift arm cylinder bottom side to the accumulator, and reduces pitching and bouncing of the machine.  Pressurized oil is accumulated in ride control accumulator (2) 1. Pressurized oil from the main pump operates lift arm cylinder (4) by shifting the lift arm spool. (Refer to Main Circuit/Lift Arm, Bucket Operation Circuit.) 2. Pressurized oil from the lift arm raise circuit (A1) flows to the bottom side of lift arm cylinder (4) and ride control valve (1). 3. When the ride control solenoid valve (3) is deactivated, pressurized oil (A1) at the bottom side of lift arm cylinder (4) is accumulated in ride control accumulator (2) through charge-cut spool (7).

A1 B1

9 11 10

5 TNDB-02-04-014

A1- Lift Arm Raise Circuit

B1- Lift Arm Lower Circuit

From MC (ON Signal)

123-

456-

789-

Charge-Cut Spool Ride Control Spool Relief Valve

Ride Control Valve Ride Control Accumulator Ride Control Solenoid Valve

Lift Arm Cylinder Pilot Pump Hydraulic Tank

T2-4-20

10- Orifice 11- Check Valve

SECTION 2 SYSTEM Group 4 Hydraulic System  Pressurized oil is stopped accumulating in ride control accumulator (2) 1. When the pressurized oil amount accumulated in ride control accumulator (2) increases over the specified value (reaches the charge-cut pressure), charge-cut spool (7) is shifted.

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

A1 B1

9 11 10

TNDB-02-04-024

A1- Lift Arm Raise Circuit

B1- Lift Arm Lower Circuit

1234-

5678-

9- Relief Valve 10- Orifice 11- Check Valve

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

Pilot Pump Hydraulic Tank Charge-Cut Spool Ride Control Spool

T2-4-21

From MC (ON Signal)

SECTION 2 SYSTEM Group 4 Hydraulic System  Ride Control: When the force pushing down the lift arm occurs 1. When the conditions for ride control exist, ON signal (a) from MC shifts the ride control solenoid valve (3).

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

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

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

3. Therefore, pressurized oil (A1) at the bottom side of lift arm cylinder (4) is supplied to ride control accumulator (2) through ride control spool (8).

fNOTE: When the ride control is deactivated, the force pushing down/up the lift arm occurs due to machine vibration when driving on rough roads.

4. In addition, pressurized oil (B1) at the rod side of lift arm cylinder (4) is supplied to hydraulic tank (6) through ride control spool (8).

B1 10

5 TNDB-02-04-025

A1- Lift Arm Raise Circuit

B1- Lift Arm Lower Circuit

1234-

5678-

9- Relief Valve 10- Orifice 11- Check Valve

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

Pilot Pump Hydraulic Tank Charge-Cut Spool Ride Control Spool

T2-4-22

From MC (ON Signal)

SECTION 2 SYSTEM Group 4 Hydraulic System  Ride Control: When the force pushing up the lift arm occurs 1. When the force pushing up the lift arm occurs, pressurized oil accumulated in ride control accumulator (2) flows to the bottom side 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.

2. Therefore, pressure decrease at bottom side circuit (A1) of lift arm cylinder (4) is regulated.

5. Make-up valve (11) draws pressurized oil from hydraulic tank (6) and prevents cavitation from occurring when the pressure in the circuit (between ride control valve and lift arm cylinder) decreases less than the specified value.

3. In case pressure difference between bottom side circuit (A1) and rod side circuit (B1) of lift arm cylinder (4) becomes small, vertical vibration of the lift arm is regulated and machine vibration is reduced.

B1 10

5 TNDB-02-04-042

A1- Lift Arm Raise Circuit

B1- Lift Arm Lower Circuit

1234-

5678-

9- Relief Valve 10- Orifice 11- Check Valve

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

Pilot Pump Hydraulic Tank Charge-Cut Spool Ride Control Spool

T2-4-23

From MC (ON Signal)

SECTION 2 SYSTEM Group 4 Hydraulic System Main Circuit The main circuit is broadly divided into the steering control circuit and front attachment control circuit. Steering Control Circuit:  Steering Priority Circuit  Relief Circuit Front Attachment Control Circuit:  Neutral Circuit  Single Operation Circuit  Combined Operation Circuit  Relief Circuit Outline: 1. Main pump (1) draws hydraulic oil from hydraulic tank (13) through suction filter (15) and delivers it to priority valve (2). 2. Priority valve (2) shifts priority spool (3) according to the steering wheel operation. (Refer to Steering Priority Circuit.) 3. Pressurized oil from main pump (1) is supplied to steering pilot valve (4) and control valve (8) by shifting priority spool (3). 4. Pressurized oil in steering pilot valve (4) moves steering cylinders (left, right) (6, 7) by shifting steering spool (5). 5. Returning oil from steering cylinders (left, right) (6, 7) returns to hydraulic tank (13) through steering pilot valve (4). 6. Pressurized oil in control valve (8) moves bucket cylinder (11) and lift arm cylinders (12) by shifting bucket spool (19) and lift arm spool (10). (Refer to Front Attachment Control Circuit.) 7. Returning oil from each cylinder and attachments (17) returns to hydraulic tank (13) through control valve (8).

T2-4-24

SECTION 2 SYSTEM Group 4 Hydraulic System

17 8

9 10

5 4

13 1

TPD8-02-04-003

12345-

Main Pump Priority Valve Priority Spool Steering Pilot Valve Steering Spool

678910-

Steering Cylinder (Left) Steering Cylinder (Right) Control Valve Bucket Spool Lift Arm Spool

1112131415-

T2-4-25

Bucket Cylinder Lift Arm Cylinder Hydraulic Tank Return Filter Suction Filter

16- Auxiliary Spool (OPT) 17- Attachments (OPT)

SECTION 2 SYSTEM Group 4 Hydraulic System Steering Control Circuit Steering Priority Circuit 1. Priority spool (3) of priority valve (2) is shifted according to the steering wheel (14) operation and the speed. 2. Pressurized oil (CF) from priority valve (2) is supplied to steering pilot valve (7). (Refer to Priority Valve Circuit (When steering is in neutral).) 3. When operating steering wheel (14), pressurized oil (CF) in steering pilot valve (7) flows to steering spool (8) through load check valve (17) and turns gerotor (9). 4. Pressurized oil delivered by the rotation of gerotor (9) moves steering cylinders (left, right) (12, 13). 5. The opening amount of orifice (19) is changed according to the steering wheel (14) operation and the speed. Then, flow rate supplied to gerotor (9) increases and decreases. 6. Load check valve (17) prevents pressurized oil which has been supplied to steering spool (8) from flowing reversely.

T2-4-26

Relief Circuit 1. Main relief valve (priority valve) (6) prevents the pressure in the circuit (between pump and steering pilot valve) from increasing over the set pressure while steering spool (8) is operated. 2. When steering spool (8) is in the neutral position, overload relief valve (10) prevents the pressure in the circuit (between steering pilot valve and steering cylinder) due to surge pressure developed by external force from increasing over the set pressure. 3. Make-up valve (18) draws pressurized oil from hydraulic tank (20) and prevents cavitation from occurring when the pressure in the circuit (between steering pilot valve and steering cylinder) decreases below the specified value. 4. Steering accumulators (11) are provided in the bottom side circuits of steering cylinders (left, right) (12, 13), and reduce the joggling of the machine taking place at operation and stop of the steering.

SECTION 2 SYSTEM Group 4 Hydraulic System

9 14

21 8 7

15 19

16 17

P EF

CF LS

5 4 LS1

LS2

20 TNDB-02-04-040

CF- Port LS1- Priority Spool Circuit LS- Port

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

123456-

78910-

Main Pump Priority Valve Priority Spool Orifice Orifice Main Relief Valve (Priority Valve)

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

13141516171819-

T2-4-27

Steering Cylinder (Right) Steering Wheel Check Valve Orifice Load Check Valve Make-Up Valve Orifice (Variable)

20- Hydraulic Tank 21- Orifice (Variable)

SECTION 2 SYSTEM Group 4 Hydraulic System Steering Priority Circuit  When not operating steering wheel 1. Priority spool (3) of priority valve (2) has moved left due to the spring force with the engine stopped.

f NOTE: When orifice (5) of priority valve (2) makes

priority spool operating pressurized oil (LS) flow to hydraulic tank (20) with steering spool (8) set in the neutral position, and warms up the priority spool circuit. As the orifice (5) diameter is small, temperature of the reduced pressurized oil rises immediately. The pressure has no effect on operation of priority spool (3).

2. When the engine starts, pressurized oil from main pump (1) flows to steering pilot valve (7) through priority spool (3) of priority valve (2). 3. At the same time, pressurized oil from main pump (1) also flows to priority spool circuits (LS1) and (LS2) through orifices (4, 5).

f NOTE: The illustration on the right shows the oil flow when not operating steering wheel (14).

4. When not operating steering wheel (14), pressurized oil from priority spool circuit (LS2) flows to hydraulic tank (20) through steering spool (8) of steering pilot 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. 6. Therefore, more pressurized oil from main pump (1) is supplied to control valve (P) through priority spool (3) and port (EF). 7. As for priority spool (3), as the notch is located on the oil passage through which pressurized oil in main pump (1) flows to port (CF) and port (EF), the ports are always connected to the delivery port in main pump (1). 8. When priority spool (3) moves right, pressurized oil routed to priority spool (3) from priority spool circuit (LS1) balances with the spring force at the position where the oil passage of port (CF) is minimized. Then, priority spool (3) stops moving.

T2-4-28

SECTION 2 SYSTEM Group 4 Hydraulic System

9 14

21 8 7

15 19

16 17

P EF

CF LS

5 4 LS1

LS2

20 TNDB-02-04-041

CF- Port LS1- Priority Spool Circuit LS- Port

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

123456-

78910-

Main Pump Priority Valve Priority Spool Orifice Orifice Main Relief Valve (Priority Valve)

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

13141516171819-

T2-4-29

Steering Cylinder (Right) Steering Wheel Check Valve Orifice Load Check Valve Make-Up Valve Orifice (Variable)

20- Hydraulic Tank 21- Orifice (Variable)

SECTION 2 SYSTEM Group 4 Hydraulic System  When operating steering wheel 1. When operating steering wheel (14), orifices (19, 21) between steering spool (8) and the sleeve of steering pilot 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. 2. When operating steering wheel (14) quickly, orifices (19, 21) are opened widely and more pressurized oil flows to gerotor (9) and steering cylinders (left, right) (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 (left, right) (12, 13). 3. When operating steering wheel (14), orifices (19, 21) are opened at the same time. Pressurized oil from port (CF) of priority valve (2) flows to gerotor (9) and steering cylinders (12, 13) through orifices (19, 21) of steering pilot valve (7). 4. When pressurized oil has flown to gerotor (9) and steering cylinders (12, 13), pressure between port (CF) of priority valve (2) and orifices (19, 21) of steering pilot valve (7) decreases.

9. 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. 10. 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.

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

f NOTE: As gerotor (9) is connected to the intermediate shaft of steering pilot valve (7), the powered steering effect is generated.

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

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 pilot valve (7). 7. At this time, pressurized oil from main pump (1) flows to both steering pilot valve (7) and control valve (P) through priority spool (3) of priority valve (2). 8. Pressurized oil in steering pilot valve (7) flows to gerotor (9) and steering cylinders (12, 13) through orifices (19, 21) between steering spool (8) and the sleeve.

T2-4-30

SECTION 2 SYSTEM Group 4 Hydraulic System

21 19 7

15 16 17

P EF

CF LS

5 4 LS1

LS2

20 TNDB-02-04-044

CF- Port LS1- Priority Spool Circuit LS- Port

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

123456-

78910-

Main Pump Priority Valve Priority Spool Orifice Orifice Main Relief Valve (Priority Valve)

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

13141516171819-

T2-4-31

Steering Cylinder (Right) Steering Wheel Check Valve Orifice Load Check Valve Make-Up Valve Orifice (Variable)

20- Hydraulic Tank 21- Orifice (Variable)

SECTION 2 SYSTEM Group 4 Hydraulic System  When the rotation of steering wheel is stopped (when steering 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) through orifice (16) of priority valve (2), and is routed to priority spool circuit (LS2). 2. When steering cylinders (left, right) (12, 13) 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, main relief valve (priority valve) (6) is activated and pressurized oil routed to priority spool circuit (LS2) flows to hydraulic tank (20) through main relief valve (priority valve) (6). 4. When main relief valve (priority valve) (6) is activated, pressurized oil in priority spool circuit (LS2) flows to hydraulic tank (20) and the pressure difference is generated between priority spool circuits (LS1) and (LS2) by orifice (5). 5. Therefore, priority spool (3) of priority valve (2) moves right. 6. Consequently, pressurized oil from priority valve (2) flows to control valve (P) through port (EF).

T2-4-32

SECTION 2 SYSTEM Group 4 Hydraulic System

14 19 7

15 16 17

P EF

CF LS

5 4 LS1

LS2

20 TNDB-02-04-043

CF- Port LS1- Priority Spool Circuit LS- Port

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

123456-

78910-

Main Pump Priority Valve Priority Spool Orifice Orifice Main Relief Valve (Priority Valve)

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

13141516171819-

T2-4-33

Steering Cylinder (Right) Steering Wheel Check Valve Orifice Load Check Valve Make-Up Valve Orifice (Variable)

20- Hydraulic Tank 21- Orifice (Variable)

SECTION 2 SYSTEM Group 4 Hydraulic System Front Attachment Control Circuit Neutral Circuit

Relief Circuit

1. Pressurized oil (EF) from the priority valve is supplied to control valve (1). (Refer to Priority Valve Circuit (When steering is in neutral).) 2. When not operating the control lever (when lift arm spool (3) and bucket spool (6) are in the neutral position), pressurized oil (EF) in control valve (1) flows back to hydraulic tank (17) through neutral circuit (12). 3. Pump control valve (8) is provided in neutral circuit (12). 4. Pump control valve (8) supplies pressurized oil in neutral circuit (12) to the regulator of pump device, and increases and decreases the pump delivery flow rate. (Refer to Pilot Circuit / Pump Control Circuit.) Single Operation Circuit 1. During single operation of lift arm or bucket, pressurized oil (EF) in control valve (1) flows to lift arm spool (3) and bucket spool (6) through load check valves (2, 4), and moves lift arm cylinder (16) and bucket cylinder (15). 2. Load check valves (2, 4) prevent pressurized oil which has been supplied to lift arm spool (3) and bucket spool (6) from flowing reversely. Combined Operation Circuit 1. During combined operation of lift arm and bucket, pressurized oil (EF) flows to lift arm spool (3) through parallel circuit (13) and load check valve (2). 2. The bucket flow rate control valve (5) is provided in parallel circuit (13), and pressurized oil (EF) flowing to bucket spool (6) is regulated. 3. Therefore, more pressurized oil (EF) is supplied to lift arm spool (3) which increases the load, and the combined controllability of lift arm and bucket is improved.

T2-4-34

1. Main relief valve (control valve) (11) prevents the pressure in the circuit (between pump and control valve) from increasing over the set pressure while operating each spool of lift arm spool (3) and bucket spool (6). 2. When lift arm spool (3) and bucket spool (6) are in the neutral position (or is operated), overload relief valve (9) prevents the pressure in the circuit (between control valve and actuator) due to surge pressure developed by external force from increasing over the set pressure. 3. In addition, overload relief valve (9) is equipped with make-up function. It draws pressurized oil from hydraulic tank (17) 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 (10) keeps the pressure in the circuit (between control valve and hydraulic tank) at the specified pressure and improves the actuator drawing operation when cavitation occurs.

SECTION 2 SYSTEM Group 4 Hydraulic System

Pc2 9

Pc1

9 4

17 TPD8-02-04-004

EF- From Priority Valve (Main Pump Pressurized Oil)

Pc1- To Pump Regulator (Pi1) Pc2- To Pump Regulator (Pi2)

12345-

68910-

Control Valve Load Check Valve (Lift Arm) Lift Arm Spool Load Check Valve (Bucket) Bucket Flow Rate Control Valve

Bucket Spool Pump Control Valve Overload Relief Valve Low-Pressure Relief Valve

11- Main Relief Valve (Control Valve) 12- Neutral Circuit 13- Parallel Circuit 15- Bucket Cylinder

T2-4-35

16- Lift Arm Cylinder 17- Hydraulic Tank

SECTION 2 SYSTEM Group 4 Hydraulic System Single Operation Circuit  Bucket Roll Back Single Operation

f NOTE: The bucket roll back operation when not operating the steering is explained here.

1. Pilot pressure oil (Pia2) shifts bucket spool (6) when the control lever is set to bucket roll back (back tilting) operation. (Refer to Pilot Circuit / Lift Arm, Bucket Operation Control Circuit.) 2. When not operating the steering wheel, more pressurized oil (EF) from the priority valve is supplied to control valve (1). (Refer to Priority Valve Circuit (When steering is in neutral).) 3. Pressurized oil (EF) from the priority valve flows to bucket spool (6) through load check valve (4). 4. Pressurized oil (EF) flowing to bucket spool (6) moves bucket cylinder (15) and tilts the bucket back. 5. Returning oil from bucket cylinder (15) returns to hydraulic tank (17) through bucket spool (6).

T2-4-36

SECTION 2 SYSTEM Group 4 Hydraulic System

Pc2 9

Pc1

16 Pia2

Pib2

9 4

17 TPD8-02-04-005

EF- From Priority Valve (Main Pump Pressurized Oil)

Pia2- Bucket Roll Back (Pilot Pressure Oil)

Pib2Bucket Dump (Pilot Pressure Oil)

12345-

68910-

11- Main Relief Valve (Control Valve) 12- Neutral Circuit 13- Parallel Circuit 15- Bucket Cylinder

Control Valve Load Check Valve (Lift Arm) Lift Arm Spool Load Check Valve (Bucket) Bucket Flow Rate Control Valve

Bucket Spool Pump Control Valve Overload Relief Valve Low-Pressure Relief Valve

T2-4-37

16- Lift Arm Cylinder 17- Hydraulic Tank

SECTION 2 SYSTEM Group 4 Hydraulic System Combined Operation Circuit  Combined operation of lift arm raise and bucket dump:

f NOTE: The lift arm raise and bucket dump operation when not operating the steering is explained here.

1. Pilot pressure oil (Pia1) shifts lift arm spool (3) in control valve (1) when the front attachment control lever is set to lift arm raise and bucket dump (frontward tilting) operation. At the same time, pilot pressure oil (Pib2) shifts bucket spool (6). (Refer to Pilot Circuit / Lift Arm, Bucket Operation Control Circuit.) 2. When not operating the steering wheel, more pressurized oil (EF) from the priority valve is supplied to control valve (1). (Refer to Priority Valve Circuit (When steering is in neutral).) 3. One of pressurized oil (EF) in control valve (1) flows to lift arm spool (3) through load check valve (2). 4. Pressurized oil (EF) flowing to lift arm spool (3) moves lift arm cylinder (16) and raises the lift arm. 5. The other of pressurized oil (EF) flows through parallel circuit (13), is regulated by the bucket flow rate control valve (5), and flows to bucket spool (6). 6. Pressurized oil (EF) flowing to bucket spool (6) moves bucket cylinder (15) and tilts the bucket forward. 7. Therefore, more pressurized oil (EF) is supplied to the lift arm circuit which increases the load, and the combined controllability is improved. 8. Returning oil from lift arm cylinder (16) and bucket cylinder (15) returns to hydraulic tank (17) through lift arm spool (3) and bucket spool (6).

T2-4-38

SECTION 2 SYSTEM Group 4 Hydraulic System

Pc2 9

Pc1

16 Pia2

Pib2

9 4

Pia1

Pib1

17 TPD8-02-04-006

EF- From Priority Valve (Main Pump Pressurized Oil) Pia1- Lift Arm Raise (Pilot Pressure Oil)

Pib1Lift Arm Lower (Pilot Pressure Oil) Pia2- Bucket Roll Back (Pilot Pressure Oil)

Pib2Bucket Dump (Pilot Pressure Oil)

12345-

68910-

11- Main Relief Valve (Control Valve) 12- Neutral Circuit 13- Parallel Circuit 15- Bucket Cylinder

Control Valve Load Check Valve (Lift Arm) Lift Arm Spool Load Check Valve (Bucket) Bucket Flow Rate Control Valve

Bucket Spool Pump Control Valve Overload Relief Valve Low-Pressure Relief Valve

T2-4-39

16- Lift Arm Cylinder 17- Hydraulic Tank

SECTION 2 SYSTEM Group 4 Hydraulic System  Combined operation of steering (right) and lift arm raise:

f NOTE: The lift arm raise operation when turning the steering wheel (right) is explained here.

1. When steering wheel (1) is rotated right, pressurized oil (CF) from the priority valve is supplied to steering pilot valve (3). At the same time, pressurized oil (EF) from the priority valve is supplied to control valve (6). (Refer to Priority Valve Circuit (When steering is in neutral).) 2. Pressurized oil (CF) in steering pilot valve (3) flows to steering spool (2) through load check valve (13). 3. Pressurized oil (CF) flowing to steering spool (2) moves steering cylinders (4, 5) at right and left and the machine turns right. (Refer to Steering Circuit.) 4. Pilot pressure oil (Pia1) shifts lift arm spool (7) in control valve (6) when the control lever is set to lift arm raise operation. 5. Pressurized oil (EF) in control valve (6) flows to lift arm spool (7) through load check valve (12). 6. Pressurized oil (EF) flowing to lift arm spool (7) moves lift arm cylinder (10) and raises the lift arm. 7. Therefore, steering (right) operation and lift arm raise operation are simultaneously made.

T2-4-40

SECTION 2 SYSTEM Group 4 Hydraulic System

5 9

10 8 3 2 1 Pib1

Pia1

13 CF

11 7

TPD8-02-04-007

CF- From Priority Valve (Main Pump Pressurized Oil)

LS- From Priority Valve (Hydraulic Oil)

Pia1- Lift Arm Raise (Pilot Pressure Oil)

Pib1- Lift Arm Lower (Pilot Pressure Oil)

1234-

5678-

Steering Wheel Steering Spool Steering Pilot Valve Steering Cylinder (Left)

Steering Cylinder (Right) Control Valve Lift Arm Spool Bucket Spool

EF- From Priority Valve (Main Pump Pressurized Oil)

9101112-

T2-4-41

Bucket Cylinder Lift Arm Cylinder Hydraulic Tank Load Check Valve

13- Load Check Valve

SECTION 2 SYSTEM Group 4 Hydraulic System Fan Circuit Outline

Prevention of Cavitation

1. Pressurized oil from fan pump (10) is supplied to the port (P1) side of fan motor (2) through fan reversing spool (4) in fan valve (1). Fan motor (2) rotates in normal.

1. Anti-void valve (3) is provided in the fan motor circuit.

Fan Reverse Rotation Control

3. Returning oil from fan motor (2) returns to hydraulic tank (11) through the oil cooler.

1. When the fan reversing switch is turned ON, fan reverse rotation control solenoid valve (5) is shifted by signal (a) from the Main Controller (MC).

2. Anti-void valve (3) refills hydraulic oil from the returning oil and prevents cavitation from occurring when the pressure in the fan circuit decreases (the fan motor speed change, engine shutdown, etc.).

fNOTE: Fan pump (10) is a gear pump. Fan pump

2. Pressurized oil from fan reverse rotation control solenoid valve (5) shifts fan reversing spool (4). 3. Therefore, pressurized oil from fan pump (10) is supplied to the port (P2) side of fan motor (2) and fan motor (2) rotates in reverse (suction direction).

Fan Speed Control 1. MC sends signal (b) and activates fan speed control solenoid valve (6) according to the signals from coolant temperature sensor and each oil temperature sensor. 2. When hydraulic oil temperature is low, pressurized oil from fan pump (10) flows to hydraulic tank (11) through fan speed control solenoid valve (6). 3. Therefore, the pressure at orifice (7, 8) sides decreases and main relief valve (9) is shifted. 4. Excess pressurized oil from fan pump (10) returns to hydraulic tank (11) through main relief valve (9). 5. Consequently, the fan motor (2) speed decreases.

T2-4-42

(10) is installed in the engine and its rotation speed is transmitted to fan pump (10).

SECTION 2 SYSTEM Group 4 Hydraulic System  Normal rotation

 Reverse rotation

P2 1

P2 3

P1 3

11 10

TNED-02-04-035

TNED-02-04-052

 Normal rotation when relieving

P2 1

P1 3

4 5

b 11

6 11

P1- Normal Rotation

P2- Reverse Rotation

1234-

Fan Valve Fan Motor Anti-Void Valve Fan Reverse Rotation Spool

TNED-02-04-036

Fan Reverse Rotation Control Solenoid Valve Fan Speed Control Solenoid Valve

78910-

T2-4-43

Orifice Orifice Fan Control Valve Fan Pump

11- Hydraulic Tank

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) and secondary steering pump (5) is activated.

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 tank (4) and delivers it to steering pilot valve (9) through load check valve (8) of secondary steering block (7).

f NOTE: The 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 pilot valve (9) moves steering cylinders (left, right) (11, 12) 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 act on secondary steering pilot valve (5) in normal state. 5. Load check valve (14) is installed so that pressurized oil from secondary steering pilot valve (5) may not flow back to the circuit at the main pump (1) side. 6. Relief valve (6) prevents the pressure in the circuit between secondary steering pump and steering pilot valve from increasing over the set pressure when secondary steering pump (5) is operated.

T2-4-44

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

10 13 9

TNDB-02-04-012

12345-

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

678910-

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

1112131415-

T2-4-45

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 (Blank)

T2-4-46

SECTION 2 SYSTEM Group 5 Electrical System Outline The electrical circuit is broadly divided into the main circuit, monitor circuit, steering column box circuit, accessory circuit, and control circuit.  The main circuit consists of the engine related circuits and accessory circuit (Key switch: ACC).  The air conditioner circuit operates the air conditioner. (Monitor Controller, Switch Panel, Air Conditioner Unit)  The steering column box circuit is operated when the machine drives. The steering column box circuit consists of the headlights, turn signal lights, brake lights, and horn.  The accessory circuit controls the various lights, the wiper, and the washer. This circuit consists of the column display controller, relays, and switches.  The control circuit controls the engine, pump, transmission, and valve. The control circuit consists of the actuators such as solenoid valves, Main Controller (MC), Engine Control Module (ECM), Transmission Control Unit (TCU), sensors, and switches. (Refer to SYSTEM/Control System.)

T2-5-1

SECTION 2 SYSTEM Group 5 Electrical System Main Circuit The major functions and components in the main circuit are as follows.  The electric power circuit supplies all electric power to all electrical systems on the machine. {Key Switch, Battery, Fuses (Fuse Box, Fusible Link)}  The CAN circuit (Key switch: ACC) performs communication between each controller.  The accessory circuit is operated when the key switch is in the ACC position.  The starting circuit starts the engine. (Key Switch, Starter, Starter Relay 1)  The charging circuit supplies electrical power to the batteries and charges them. {Alternator, (Regulator)}  The surge voltage prevention circuit prevents the occurrence of surge voltage developed when stopping the engine. (Load Dump Relay)  The pilot shut-off circuit controls the pilot shut-off solenoid valve by operating to the control lever lock switch. The pilot shut-off solenoid valve controls pilot pressurized oil which flows from the pilot pump to the pilot valve. (Pilot Shut-Off Solenoid Valve, Control Level Lock Switch)  The auto shut-down circuit (option) automatically stops the engine when the specified conditions exist. (MC, Auto Shut-Down Relay, ACC Cut Relay, Key Switch ON Cut Relay)  The engine stop circuit (key switch: OFF) stops the engine by using ECM. (MC, ECM)

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) negative terminal is grounded to the body. The circuit from the battery (1) positive terminal is connected as shown below when key switch (26) is in the OFF position. Battery (1)

Fusible Link Key Switch (4) Terminal B A (65 A) (25) Fuse Box B (27) Terminal Light Switch (19) #2 Terminal Cab Light (20) #3 Radio (Backup Power) (21) Terminal Auxiliary (Power) (22) #4 Terminal Auxiliary (Power) (14) #5 Terminal Horn (Power) (34) #6 Horn Switch (Power) (35) Terminal Flasher Relay (15) #7 Hazard Light Switch (33) Terminal Load Dump Relay (28) #8 MC (Power) (29) Monitor Controller (Power) (30) Column Display Controller (Power) (31) Communication Terminal (Power) (32) ECM Timer (23) Terminal TCU (Power) (11) #9 Terminal ECM (Power) (12) #10 Fuel Pump (Power) (13) Fusible Link Fuse Box A (37) Terminal DEF Sensor Relay (38) C (45 A) (36) #16 Terminal Supply Module Relay (39) #17 Terminal DEF Heater Relay (40) #18

T2-5-4

SECTION 2 SYSTEM Group 5 Electrical System 1

25 26

18 17 16

40 39 38 23 28 29 30 31 32 11 12 13 14 15 33

8 9 10 5 7 6 2 3

4 22 21 20 19 35 34

111121314151920-

Battery TCU (Power) ECM (Power) Fuel Pump (Power) Auxiliary (Power) Flasher Relay Light Switch Cab Light

2122232425262728-

Radio (Backup Power) Auxiliary (Power) ECM Timer Battery Relay Fusible Link A (65 A) Key Switch Fuse Box B Load Dump Relay

29- MC (Power) 30- Monitor Controller (Power) 31- Column Display Controller (Power) 32- Communication Terminal (Power) 33- Hazard Light Switch 34- Horn (Power)

T2-5-5

TNEK-02-05-001

353637383940-

Horn Switch (Power) Fusible Link C (45 A) Fuse Box A DEF Sensor Relay Supply Module Relay DEF Heater Relay

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 bus (4)), that consists of CAN1 (1), CAN2 (5), and CAN3 (18) are equipped for this machine. CAN1 (1) and CAN3 (18) are used for the engine and transmission controls. CAN2 (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 the 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 bus (4).

T2-5-6

SECTION 2 SYSTEM Group 5 Electrical System 1

3 5

2 4 TNEK-02-01-001

17 18

17 11

7 15 17

1 12

TNEK-02-01-002

12345-

CAN1 CAN-H(High) CAN-L(Low) CAN Bus CAN2

VGT (Variable Geometry Turbo) Controller 7- ECM (Engine Control Module) 8- MC (Main Controller) 9- TCU (Transmission Controller) 10- Communication Controller

111213141516-

T2-5-7

Monitor Controller MPDr. (Maintenance Pro Dr.) Air Conditioner Controller Column Display Controller Monitor Control Unit Information Control Unit

17- Termination Resistor (120 Ω) 18- CAN3

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. The circuit from terminal ACC (6) in key switch (4) is connected to radio (9) through fuse #1 in fuse box B (8), and makes radio (9) operation possible.

T2-5-8

SECTION 2 SYSTEM Group 5 Electrical System 10

1 8

TNEG-02-05-002

245-

Battery Relay Key Switch ACC Position

689-

Terminal ACC Fuse Box B Radio

10- Battery 11- Fusible Link A (65 A)

T2-5-9

SECTION 2 SYSTEM Group 5 Electrical System Starting Circuit (Key Switch: START)  Forward/Reverse Lever in Neutral

fNOTE: When key switch (4) is set to START position (5)

with forward/reverse lever (10) set in neutral (N) position (20), the starter motor rotates and the engine starts. (Refer to Neutral Engine Start Circuit.) 9. When forward/reverse lever (10) is in neutral (N) position (24), circuit (c) from fuse #14 in fuse box B (28) is disconnected by forward/reverse lever (10). Then, neutral relay (15) is turned OFF.

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). 2. Current from terminal M (6) flows to fuse #13 and fuse #14 in fuse box B (28) through key switch ON cut relay (9).

10. Current (g) from terminal J2-83 of ECM (12) flows to the coil in starter cut relay (16) and turns ON starter cut relay (16).

3. Current from fuse #13 in fuse box B (28) excites battery relay (2). Current from battery (1) is routed to terminal #30 of starter (18) and terminal C of starter relay 1 (17) through battery relay (2).

11. Current from terminal ST (7) flows to terminal S in starter relay 1 (17) through neutral relay (15) and starter cut relay (16).

4. Current from fuse #13 in fuse box B (28) flows to Engine Control Module (ECM) (12), column display controller (19), monitor controller (20), and Main Controller (MC) (22) as the signal indicating that key switch (4) is in ON or START position (5). 5. Current (b) fuse #13 in fuse box B (28) flows to the coil in ECM main relay (21) and turns ON ECM main relay (21).

12. Current flows to the coil in starter relay 1 (17) and turns ON starter relay 1 (17). 13. Current flows to terminal #50 in starter (18) through terminal B in starter relay 1 (17). 14. The relay in starter (18) is turned ON and the starter motor rotates.

6. When ECM main relay (21) is ON, current from fuse #10 in fuse box B (28) flows to ECM (12) through ECM main relay (21) and turns ON the ECM (12) main power. 7. At the same time, current from fuse #10 in fuse box B (28) flows to various relays (h) of the urea SCR system through ECM main relay (21). 8. ECM (12) controls the condition of the engine to be able to start.

T2-5-10

SECTION 2 SYSTEM Group 5 Electrical System 23 24 25

43 67 64

10 3 2

a 9 d e

19 20 12 22

c 28 4

13 5

12 15

18 a

16 g 17

h 10

27 TNEK-02-05-002

From Fuse #13 in Fuse Box B (28)

From Fuse #14 in Fuse Box B (28)

Various Relays (h) of Urea SCR System

From Terminal J2-83 in ECM

1234567-

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

Key Switch ON Cut Relay (Option) Forward/Reverse Lever Transmision Control Unit (TCU) Engine Control Module (ECM) Neutral Relay Starter Cut Relay

17181920212223-

Starter Relay 1 Starter Column Display Controller Monitor Controller ECM Main Relay Main Controller (MC) Forward (F) Position

24252728-

Neutral (N) Position Reverse (R) Position ECM Timer Fuse Box B

1011121516-

T2-5-11

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 terminals ACC (7) and M (8) in key switch (4) with key switch (4) set in the ON position. 3. Alternator (5) starts generating electricity with the engine running. Current from terminal B in alternator (5) flows to battery (1) through fusible link (70 A) (11) and battery relay (2), and charges batteries (1). 4. In addition, current from terminal L in alternator (5) flows to column display controller (12). 5. Column display controller (12) detects the alternator (5) generating electricity according to current from terminal L in alternator (5), and turns off alternator indicator (14) on the monitor.

T2-5-12

SECTION 2 SYSTEM Group 5 Electrical System

3 1

10 13

4 7 8

14 1-14

TNEK-02-05-004

1234-

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

57810-

Alternator Terminal ACC Terminal M Fuse Box B

11- Fusible Link (70 A) 12- Column Display Controller 14- Alternator Indicator

T2-5-13

SECTION 2 SYSTEM Group 5 Electrical System Alternator Operation  Alternator (5) consists of field coil FC, stator coil SC, and diodes D.  Regulator (6) consists of transistors T1, T2, Zener diode ZD, and resistances R1 to R6, RF.  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), and collector C is connected to emitter E. Therefore, field coil FC is grounded through transistor T1.

 At the beginning, no current is flowing to field coil FC. When the rotor starts rotating, the alternate current is generated in stator coil SC due to the rotor remnant magnetism.  When current flows to field coil FC, the rotor is further magnetized and the generating voltage increases. Then, current flowing to field coil FC increases. Therefore, the generating voltage increases further and batteries (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-

T2-5-14

Alternator Regulator

SECTION 2 SYSTEM Group 5 Electrical System Regulator Operation  When the 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 the transistor T2 operation, and transistor T1 is turned OFF.  No current flows to filed coil FC and the generating voltage at stator coil SC decreases.

 When the 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 to field coil FC and the generating voltage at stator coil SC increases. The above operation is repeated and 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-

T2-5-15

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 the inertia force just after key switch (4) is turned OFF and 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 controller, possibly cause. In order to prevent the occurrence of surge voltage, the surge voltage prevention circuit is provided. 4. When alternator (5) is generating electricity, the generating current from terminal L in alternator (5) flows to terminal #A15 of monitor controller (6). Monitor controller (6) connects terminal #D8 to the ground. 5. Therefore, current flows to the exciting circuit in load dump relay (3) and load dump relay (3) is turned ON. 6. Consequently, even if key switch (4) is set to the OFF position with the engine running, current from batteries (1) continues to excite battery relay (2) through load dump relay (3). 7. In addition, when a specified time has passed since alternator (5) stops generating electricity, monitor controller (6) disconnects terminal #D8 from the ground. Therefore, battery relay (2) is turned OFF.

T2-5-16

SECTION 2 SYSTEM Group 5 Electrical System 10 f

8 6

12 2

D8 B-36 A15

g 11

7 14

b 5

TNEK-02-05-005

123-

Battery Battery Relay Load Dump Relay

456-

Key Switch Alternator Monitor Controller

7- Terminal ACC 10- Fuse Box B 11- Fusible Link (70 A)

T2-5-17

12- Fusible Link A (65A) 14- Terminal M

SECTION 2 SYSTEM Group 5 Electrical System Pilot Shut-Off Circuit (Key Switch: ON)  Front Control Lever Lock Switch: ON (Lock) Position (6)

 Front Control Lever Lock Switch: OFF (Release) Position (5)

1. When the key switch is in the ON position, the circuit from the battery relay is connected to fuse #16 in fuse box B (1). 2. When the control lever lock switch (4) is set to ON (lock) position (6), current (a) from fuse #16 in fuse box B (1) flows to the ground through pilot shut-off relay (3) and the control lever lock switch (4). Then, pilot shut-off relay (3) is turned ON. 3. As the ground circuit in the pilot shut-off solenoid valve (2) is disconnected, the pilot shut-off solenoid valve (2) is turned OFF. 4. Pressurized oil from the pilot pump is blocked by the pilot shut-off solenoid valve (2). 5. In addition, current from fuse #11 in fuse box B (1) turns on the indicator of the control lever lock switch (4).

T2-5-18

1. When the control lever lock switch (4) is set to OFF (unlock/release) position (5), the ground circuit in the control lever lock switch (4) is disconnected. 2. As pilot shut-off relay (3) is turned OFF, the ground circuit in the pilot shut-off solenoid valve (2) is connected. 3. The pilot shut-off solenoid valve (2) is turned ON and pressurized oil from the pilot pump is supplied to the pilot valve.

SECTION 2 SYSTEM Group 5 Electrical System  Control Lever Lock Switch: ON (Lock) Position (6) 1 a 16 2

b 11 4 TNED-02-05-007

 Control Lever Lock Switch: OFF (Release) Position (5) 1 a 16 2

b 11 4 TNED-02-05-026

From Battery Relay

From Light Switch

12-

Fuse Box B Pilot Shut-Off Solenoid Valve

34-

Pilot Shut-Off Relay Control Lever Lock Switch

56-

T2-5-19

OFF (Release) Position ON (Lock) Position

SECTION 2 SYSTEM Group 5 Electrical System Auto Idling Stop Circuit 1. When key switch (4) is in ON position (15), current (d) from terminal M (5) excites battery relay (2) through key switch ON cut relay (18) and fuse #13 in fuse box B (6).

fNOTE: Return key switch (4) to the OFF or ACC position

2. Circuit (d) from terminal M (5) is connected to each coil of auto shut-down relay (19), ACC cut relay (9), and key switch ON cut relay (18). 3. When all following conditions exist and the auto idling stop set time has passed, Main Controller (MC) (11) connects terminal #B17 to the ground in it. (Refer to SYSTEM/Control System.) 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  Overheat Alarm: OFF  Coolant Temperature: 100 ºC (212 ºF) or less  Hydraulic Oil Temperature: 100 ºC (212 ºF) or less  Torque Converter Oil Temperature: 110 ºC (230 ºF) or less  Aftertreatment device manual regeneration is not operating  Communication between ECM and column display controller: Normal  Transmission learning is not operating  Pump Delivery Pressure: Beyond specified value (Reference: 5 MPa (51 kgf/cm2, 725 psi)  Engine: Running 4. Auto idling stop relay (19) is turned ON. At the same time, key switch ON cut relay (18) is also turned ON. 5. Current (f ) indicating that key switch (4) is in ON position (15) stops flowing to terminal J2-5 of Engine Control Module (ECM) (12) through fuse #13 in fuse box B (6). 6. At the same time, battery relay (2) is turned OFF. 7. ECM (12) stops injection of the injector and stops the engine. 8. When the engine stops, ECM (12) turns OFF ECM main relay (20) after 30 seconds due to the timer function.

T2-5-20

and reset it to the START position when restarting the engine.

SECTION 2 SYSTEM Group 5 Electrical System

b B17

3 2

1 18

d e g f

16 13 4

6 15

h e 19 g d

6 10

20 b

17 TNEK-02-05-006 f-

To ECM (12) Terminal J2-5

12345-

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

69111215-

Fuse Box B ACC Cut Relay (Option) Main Controller (MC) Engine Control Module (ECM) ON position

16- OFF Position 17- ECM Timer 18- Key Switch ON Cut Relay (Option) 19- Auto Idling Stop Relay

T2-5-21

20- ECM Main Relay

SECTION 2 SYSTEM Group 5 Electrical System Engine Stop Circuit 1. When key switch (4) is set to OFF position (16), current (f ) from terminal M (5) in key switch (4) stops flowing to terminal J2-5 of Engine Control Module (ECM) (12). 2. ECM (12) stops fuel injection of the injector and stops the engine. 3. ECM main relay (20) is turned ON for 30 seconds due to the timer (17) function. ECM (12) is kept ON. 4. When 30 seconds have passed, ECM main relay (20) is turned OFF and the ECM (12) power is turned OFF.

T2-5-22

SECTION 2 SYSTEM Group 5 Electrical System

11 B17

h 3 2

1 8

d e

16 13 4

6 15

h e 10

9 12

d 5

6 10

20 b

17 TNEK-02-05-007 f-

To ECM (12) Terminal J2-5

12345-

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

69111215-

Fuse Box B ACC Cut Relay (Option) Main Controller (MC) Engine Control Module (ECM) ON position

16- OFF Position 17- ECM Timer 18- Key Switch ON Cut Relay (Option) 19- Auto Idling Stop Relay

T2-5-23

20- ECM Main Relay

SECTION 2 SYSTEM Group 5 Electrical System Air Conditioner Circuit 1. The operation on switch panel (2) is displayed on monitor (1) through monitor controller (3). 2. When the setting for air conditioner is operated on switch panel (2), the signal is sent to monitor controller (3). 3. Monitor controller (3) sends the signal to air conditioner unit (6) by using the CAN communication and the air conditioner is operated.

T2-5-24

SECTION 2 SYSTEM Group 5 Electrical System

a 13 15

9 TNED-02-05-010

4 a-

From Battery

123-

Monitor Switch Panel Monitor Controller

456-

Fuse Box A Fuse Box B Air Conditioner Unit

T2-5-25

Controller Area Network (CAN) 2

SECTION 2 SYSTEM Group 5 Electrical System (Blank)

T2-5-26

SECTION 2 SYSTEM Group 5 Electrical System Steering Column Box Circuit  The headlight circuit turns on and off the headlights, clearance lights, license lights, and tail lights.  The hazard light circuit turns on and off the hazard lights.  The turn signal light circuit turns on and off the turn signal lights.  The horn circuit sounds the horn.  The reverse buzzer circuit activates and deactivates the reverse buzzer.  The brake light circuit turns on and off the brake lights.  The parking brake circuit applies and releases the parking brake.

T2-5-27

SECTION 2 SYSTEM Group 5 Electrical System Headlight Circuit Clearance Light, License Light, Tail Light Circuit (Light Switch: Clearance Light Position) 1. Circuit (a) from the battery is connected to light switch (24) through fuse #2 in fuse box B (1). 2. When light switch (24) is set to clearance light position (20), the circuit from fuse #2 in fuse box B (1) is connected to fuses #11 and #12 in fuse box B (1) through light switch (24). 3. Current from fuses #11 and #12 flows to clearance lights (9, 25), tail lights (4, 7), and license light (8), and connects to the ground. 4. Clearance lights (9, 25), tail lights (4, 7), and license light (8) is turned on. 5. The circuit from fuse #2 in fuse box B (1) is connected to terminal #1-5 in column display controller (10) through light switch (24). 6. Column display controller (10) checks the input signal of terminal #1-5. 7. Column display controller (10) turns on clearance light indicator (18).

fNOTE: License light (8) is option.

T2-5-28

SECTION 2 SYSTEM Group 5 Electrical System 20 1

24 S OFF H

a Fuse#2

1-5

1-3

28 25 Fuse#11

8 9

Fuse#12

26 27

16 14

b 26 Fuse#6 13

b 1

Fuse#2

17 b Fuse#19

TNEK-02-05-011

From Battery

From Battery Relay

134789-

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

101314151617-

Column Display Controller Headlight Relay (Right) Headlight (Left) Headlight (Right) High Beam High Beam Relay

182021222324-

T2-5-29

Clearance Light Indicator Clearance Light Position Headlight Position Low Beam Position High Beam Position Light Switch

25262728-

Clearance Light (Right) Fuse Box A Headlight Relay (Left) High Beam Indicator

SECTION 2 SYSTEM Group 5 Electrical System Headlight Circuit

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

fNOTE: When light switch (24) is turned on with the

beam position (22) is explained here.

1. When light switch (24) is set to headlight position (21), the circuit from fuse #2 in fuse box B (1) is connected to dimmer switch (3) through light switch (24). 2. When dimmer switch (3) is set to low beam position (22), the circuit from fuse #2 in fuse box B (1) is connected to the coils in headlight relays (right and left) (13, 27) through dimmer switch (3), and is connected to the ground. 3. Headlight relays (right and left) (13, 27) are turned ON. 4. The circuits from fuses #2 and #6 in fuse box A (26) are connected to the ground through in headlight relays (right and left) (13, 27) and headlights (left, right) (14, 15). 5. Headlights (left, right) (14, 15) are turned on.

T2-5-30

head lights in the on position (21), head lights (14, 15), clearance lights (9, 25), tail lights (4, 7), and license light (8) are all turned on.

SECTION 2 SYSTEM Group 5 Electrical System 20 1

24 S OFF H

a Fuse#2

1-5

1-3

28 25 Fuse#11

8 9

Fuse#12

26 27

16 14

b 26 Fuse#6 13

b 1

Fuse#2

17 b Fuse#19

TNEK-02-05-012

From Battery

From Battery Relay

134789-

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

101314151617-

Column Display Controller Headlight Relay (Right) Headlight (Left) Headlight (Right) High Beam High Beam Relay

182021222324-

T2-5-31

Clearance Light Indicator Clearance Light Position Headlight Position Low Beam Position High Beam Position Light Switch

25262728-

Clearance Light (Right) Fuse Box A Headlight Relay (Left) High Beam Indicator

SECTION 2 SYSTEM Group 5 Electrical System High Beam Circuit

fNOTE: When the turn signal lever is lowered with head

fNOTE: The high beam circuit operation with light

switch (24) set in head light on position (21) is explained here.

1. When dimmer switch (3) is set to high beam position (23), the circuit from fuse #2 in fuse box B (1) is connected to the ground through the coil in high beam relay (17). 2. High beam relay (17) is turned ON. 3. The circuit from from fuse #19 in fuse box B (1) is connected to the ground through high beam relay (17) and high beams (16) in headlights (left, right) (14, 15). 4. High beams (16) in headlights (left, right) (14, 15) are turned on. 5. The circuit from fuse #19 in fuse box B (1) is connected to terminal #1-3 in column display controller (10) through high beam relay (17). 6. Column display controller (10) judges the input signal of terminal #1-3. 7. Column display controller (10) turns on high beam indicator (28).

T2-5-32

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

SECTION 2 SYSTEM Group 5 Electrical System 20 1

24 S OFF H

a Fuse#2

1-5

1-3

25 Fuse#11

8 9

Fuse#12

26 27

16 14

b 26

Fuse#6

b 1

Fuse#2

17 b Fuse#19

TNEK-02-05-013

From Battery

From Battery Relay

134789-

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

101314151617-

Column Display Controller Headlight Relay (Right) Headlight (Left) Headlight (Right) High Beam High Beam Relay

182021222324-

T2-5-33

Clearance Light Indicator Clearance Light Position Headlight Position Low Beam Position High Beam Position Light Switch

25262728-

Clearance Light (Right) Fuse Box A Headlight Relay (Left) High Beam Indicator

SECTION 2 SYSTEM Group 5 Electrical System Hazard Light Circuit (Key Switch: OFF) 8. Current flowing through right turn signal light relay (4) blinks the indicator of hazard light switch (3).

1. Circuit (a) from the battery is connected to the ground through flasher relay (2).

fNOTE: The hazard light circuit can be activated even if

2. When hazard light switch (3) is set to ON position (21), the circuit from fuse #7 in fuse box B (1) is connected to the ground through hazard light switch (3) and the coils in turn signal light relays (right, left) (4, 5).

the key switch is in the OFF position.

3. Turn signal light relays (right, left) (4, 5) are turned ON. 4. Current from terminal L in flasher relay (2) intermittently flows to the ground through turn signal light relays (right, left) (4, 5) and all turn signal lights (6, 9, 22, 23). 5. All turn signal lights (6, 9, 22, 23) blink. 6. At the same time, current from terminal L in flasher relay (2) intermittently flows to the ground through terminals #1-1 and #1-4 in column display controller (10). 7. Column display controller (10) blinks right and left turn signal indicators (18, 19).

T2-5-34

SECTION 2 SYSTEM Group 5 Electrical System

2 1 a Fuse#7

3 1-1 1-4

4 12 11

L N R

16 9

c 17

Fuse#8

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 Turn Signal Light Relay (Right) Turn Signal Light Relay (left) Turn Signal Light (Right Front)

91011121314-

Turn Signal Light (Left Rear) Column Display Controller Turn Signal Lever Left Turn Position Neutral Position Right Turn Position

151617181920-

T2-5-35

Diode P Diode K Fuse Box A Right Turn Signal Indicator Left Turn Signal Indicator OFF Position

21- ON Position 22- Turn Signal Light (Right Rear) 23- Turn Signal Light (Left Front)

SECTION 2 SYSTEM Group 5 Electrical System Turn Signal Light Circuit

fNOTE: The operation with turn signal lever (11) set in

7. At the same time, current from terminal L in flasher relay (2) flows to the ground through terminal #1-4 in column display controller (10).

left turn position (12) is explained here.

1. Circuit (a) from the battery is connected to the ground through fuse #7 in fuse box B (1) and flasher relay (2). 2. When the key switch is in the ON position, circuit (c) from the battery is connected to fuse #8 in fuse box A (17) through the battery relay and the fusible link (70A).

8. Column display controller (10) blinks left turn signal light indicator (19).

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

3. When turn signal lever (11) is set to left-hand position (12), the circuit from fuse #8 in fuse box A (17) is connected to the ground through turn signal lever (11), diode K (16), and the coil in the left turn signal light relay (5). 4. The left turn signal light relay (5) is turned ON. 5. Current from terminal L in flasher relay (2) intermittently flows to the ground through the left turn signal light relay (5) and left turn signal lights (9, 23) at front and rear. 6. Left turn signal lights (9, 23) at front and rear blink.

T2-5-36

position (14), turn signal lights (right front, right rear) (6, 22) blink. At the same time, column display controller (10) blinks right turn signal indicator (18).

SECTION 2 SYSTEM Group 5 Electrical System

2 1 a Fuse#7

3 1-1 1-4

4 12 11

L N R

16 9

c 17

Fuse#8

TNED-02-05-015

ab-

From Battery From Fuse #12 in Fuse Box B

From Battery Through Battery Relay and Fusible Link (70A)

123456-

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

91011121314-

Turn Signal Light (Left Rear) Column Display Controller Turn Signal Lever Left Turn Position Neutral Position Right Turn Position

151617181920-

T2-5-37

Diode P Diode K Fuse Box A Right Turn Signal Indicator Left Turn Signal Indicator OFF Position

21- ON Position 22- Turn Signal Light (Right Rear) 23- Turn Signal Light (Left Front)

SECTION 2 SYSTEM Group 5 Electrical System Horn Circuit (Key Switch: OFF) 1. When eigther of horn switches (3, 7) is pushed, circuit (a) is connected to the ground through fuse #6 in fuse box B (1) and the coil in horn relay (2). 2. When horn relay (2) is turned ON, current from fuse #6 in fuse box B (1) activates horns (4, 5).

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

T2-5-38

SECTION 2 SYSTEM Group 5 Electrical System

1 a Fuse#6

7 TNED-02-05-016

From Battery

12-

Fuse Box B Horn Relay

34-

Horn Switch Horn (HIGH)

57-

T2-5-39

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, circuit (a) from the battery is connected to fuse #7 in fuse box A (1) through the battery relay and the fusible link (70A). 2. Circuit (b) from terminal M through fuse #3 in fuse box B is connected to terminal #7 in Transmission Control Unit (TCU) (6) through the coil in back buzzer relay (2). 3. When forward/reverse lever (4) is set to reverse position (10), circuit (c) from fuse #14 in fuse box B is connected to terminal #64 in TCU (6) through forward/reverse lever (4). 4. TCU (6) checks the input signal of terminal #64, and connects terminal #7 in TCU (6) to the ground. 5. When back buzzer relay (2) is turned ON, current from fuse #7 in fuse box A (1) activates back buzzer (3).

T2-5-40

SECTION 2 SYSTEM Group 5 Electrical System

1 3 2

a Fuse#7

10 7

6 64 4

TNEK-02-05-017

From Battery

From Terminal M in Key Switch Through Fuse #13 in Fuse Box B

123-

Fuse Box A Back Buzzer Relay Back Buzzer

46-

Forward/Reverse Lever Transmission Control Unit (TCU)

8- Forward Position 9- Neutral Position 10- Reverse Position

T2-5-41

From Fuse #14 in Fuse Box B

SECTION 2 SYSTEM Group 5 Electrical System Brake Light Circuit 1. When the key switch is in the ON position, circuit (a) from the battery is connected to fuse #8 in fuse box A (1) through the battery relay and the fusible link (70A). 2. When the brake pedal is operated, brake light switch (5) is turned ON. 3. The circuit from fuse #8 in fuse box A (1) is connected to the ground through the coil in brake light relay (2). 4. When brake light relay (2) is turned ON, the circuit from fuse #8 in fuse box A (1) is connected to the ground through brake light relay (2) and brake lights (right, left) (3, 4). 5. Brake lights (right, left) (3, 4) are turned on.

T2-5-42

SECTION 2 SYSTEM Group 5 Electrical System

a Fuse#8

5 a-

From Battery Through Battery Relay and Fusible Link (70A)

12-

Fuse Box A Brake Light Relay

34-

Brake Light (Right) Brake Light (Left)

T2-5-43

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))

7. Pressurized oil (parking brake release pressurized oil) from the pilot pump is supplied to the parking brake through the parking brake solenoid valve (6).

IMPORTANT: The parking brake can be released only while the engine runs. 1. Circuit (b) from fuse #14 in fuse box B is connected to terminal #4 in parking brake switch (3) through parking brake relay 1 (2) (supply side) and the coil in parking brake relay 2 (4). 2. When parking brake switch (3) is set to release position (9), parking brake switch (3) connects terminal #4 to the ground through terminal #6 in it. 3. Parking brake relay 2 (4) is turned ON.

8. The spring of the parking brake is pushed back and the parking brake is released. 9. When parking brake switch (3) in release position (9) is released, parking brake switch (3) returns to neutral position (10). 10. Current from terminal #4 in parking brake switch (3) stops flowing to parking brake relay 2 (4). 11. As the self-exciting circuit is formed in parking brake relay 2 (4), the parking brake solenoid valve (6) continues to be activated.

4. Circuit (d) from the battery relay is connected to the ground through fuse #10 in fuse box A (8) and parking brake relay 2 (4).

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

5. The parking brake solenoid valve (6) is activated. 6. At the same time, current flowing through the coil in parking brake relay 2 (4) flows to parking brake relay 2 (4) (supply side) through diode G (5) and the self-exciting circuit is formed.

T2-5-44

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

SECTION 2 SYSTEM Group 5 Electrical System

1 A15

9 10 11

D13 1 2 3 4 5 6 9

8 d Fuse#10

6 5

4 TNED-02-05-019

ab-

From Terminal L in Alternator From Fuse #14 in Fuse Box B

cd-

From Fuse #12 in Fuse Box B From Battery Relay

123-

Monitor Controller Parking Brake Relay 1 Parking Brake Switch

456-

Parking Brake Relay 2 Diode G Parking Brake Solenoid Valve

789-

T2-5-45

Diode F Fuse Box A Release Position

10- Neutral Position 11- Apply Position

SECTION 2 SYSTEM Group 5 Electrical System Parking Brake: Applied (Parking Brake Switch: Apply Position (11)) 1. The circuit from terminal M in the key switch is connected to fuse #14 in fuse box B through the key ON cut relay.

fNOTE: This parking brake system is spring applied,

2. Circuit (b) from fuse #14 in fuse box B is connected to terminal #1 in parking brake switch (3) through the coil side of parking brake relay 1 (2). 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. When parking brake relay 1 (2) is turned ON, the circuit from parking brake relay 1 (2) (supply side) is disconnected from the coil of parking brake relay 2 (4). 5. Current (d) from the battery relay does not flow to the parking brake solenoid valve (6) through fuse #10 in fuse box A (8). Then, the parking brake solenoid valve (6) is turned OFF. 6. Pressurized oil (parking brake release pressurized oil) from the pilot pump is blocked by the parking brake solenoid valve (6). 7. Pressurized oil in the parking brake flows back to the hydraulic tank. Then, the parking brake is applied by the spring force.

T2-5-46

oil release type. As pressurized oil from the pilot pump (parking brake release pressurized 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.

SECTION 2 SYSTEM Group 5 Electrical System

1 A15

9 10 11

D13 1 2 3 4 5 6 9

8 d Fuse#10

6 5

4 TNED-02-05-020

ab-

From Terminal L in Alternator From Fuse #14 in Fuse Box B

cd-

From Fuse #12 in Fuse Box B From Battery Relay

123-

Monitor Controller Parking Brake Relay 1 Parking Brake Switch

456-

Parking Brake Relay 2 Diode G Parking Brake Solenoid Valve

789-

T2-5-47

Diode F Fuse Box A Release Position

10- Neutral Position 11- Apply Position

SECTION 2 SYSTEM Group 5 Electrical System (Blank)

T2-5-48

SECTION 2 SYSTEM Group 5 Electrical System Accessory Circuit  The work light circuit turns on the work light. (Work Light Switch, Work Light Relay)  The wiper circuit operates the intermittent operation of wiper and the washer. (Column Display Controller, Wiper/Washer Switch, Wiper Relay, Washer Relay)  The cab light circuit turns on/off the cab light by shifting the switch or by opening/closing the door.

T2-5-49

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 ON 2 position (11) is explained here.

1. When the key switch is in the ON position, circuit (b) from the battery relay through the fusible link (70A) is connected to fuse #5 in fuse box A (3) and fuse #17 in fuse box B (1). 2. The circuit from fuse #5 in fuse box A (3) is connected to the work light (front) relay (19). The circuit from fuse #17 in fuse box B (1) is connected to the work light (rear) relay (6). 3. When light switch (18) is set to clearance light position (14) or head light position (15), the circuit from fuse #2 in fuse box B (1) is connected to terminal #1 and terminal #4 in work light switch (4). 4. When work light switch (4) is set to ON 2 position (11), the circuit from fuse #2 in fuse box B (1) is connected to the ground through terminal #3 in work light switch (4) and the coil in the work light (front) relay (19). 5. When the work light (front) relay (19) is turned ON, current from fuse #5 in fuse box A (3) turns on work light (front right) (7) and work light (front left) (8). 6. The circuit from fuse #5 in fuse box A (3) is connected to the ground through terminal #1-2 in column display controller (21). 7. Column display controller (21) turns on work light indicator (16). 8. Current from fuse #12 in fuse box B (1) flows to terminal #8 in work light switch (4) and turns on the indicator.

T2-5-50

(13), work light (front right) (7), work light (front left) (8), work light (rear right) (9), and work light (rear left) (10) are turned on.

SECTION 2 SYSTEM Group 5 Electrical System

3 1

S OFF H

Fuse#5

ON2 OFF ON1

1 2 3 4 5 6 8 9

Fuse#12

1-2

11 20 13

Fuse#2

9 10

b Fuse#17

TNED-02-05-021

From Battery

From Battery Relay Through Fusible Link (70A)

13467-

Fuse Box B Fuse Box A Work Light Switch Work Light (Rear) Relay Work Light (Front Right)

89101113-

Work Light (Front Left) Work Light (Rear Right) Work Light (Rear Left) ON 2 Position ON 1 Position

1415161819-

T2-5-51

Clearance Light Position Headlight Position Work Light Indicator Light Switch Work Light (Front) Relay

20- OFF Position 21- 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 Intermittent (INT.) position (15) is explained here.

1. The circuit from fuse #4 in fuse box A (1) is connected to terminal #2-23 in column display controller (14) through the coil in front wiper relay 1 (5). 2. When front wiper/washer switch (8) is set to INT. position (15), the circuit from terminal #2-13 in column display controller (14) is connected to the ground through terminal #7 and terminal #1 in front wiper/washer switch (8). 3. Column display controller (14) intermittently connects terminal #2-23 to the ground in it. Then, front wiper relay 1 (5) is turned ON/OFF repeatedly. 4. When front wiper relay 1 (5) is ON, the circuit from fuse #4 in fuse box A (1) is connected to the ground through the slow speed (21) circuit in front wiper motor (3), front wiper relay 2 (20), and front wiper relay 1 (5). 5. The front wiper is operated at slow speed and intermittently.

T2-5-52

SECTION 2 SYSTEM Group 5 Electrical System

1 c 7

Fuse#4

6 14 8 17 9 2-24

a b

2-23 2-16

2-13 2-14 2-15

2 c Fuse#18

13 TNED-02-05-022

From Front Wiper Relay 2

From Front Wiper Relay 1

From Battery Relay

123567-

Fuse Box A Fuse Box B Front Wiper Motor Front Wiper Relay 1 Front Washer Motor Front Washer Relay

8910111213-

Front Wiper/Washer Switch Rear Wiper/Washer Switch Rear Wiper Motor Rear Washer Motor Rear Wiper Relay Rear Washer Relay

141516171920-

Column Display Controller Intermittent (INT.) Position LOW Position Washer Position Fast Speed Front Wiper Relay 2

T2-5-53

21- Slow Speed

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), terminals #9 and #1 are connected inside. 2. The circuit from fuse #18 in fuse box B (2) is connected to the ground through the coil in rear wiper relay (12) and terminal #9 in rear wiper/ washer switch (9). 3. Rear wiper relay (12) is turned ON. Current from fuse #18 in fuse box B (2) flows to rear wiper motor (10) and operates the rear wiper at slow speed.

T2-5-54

SECTION 2 SYSTEM Group 5 Electrical System

a 1 c 7

Fuse#4

6 14 8 17 9 2-24

a b

2-23 2-16

2-13 2-14 2-15

2 c Fuse#18

13 TNED-02-05-023

From Front Wiper Relay 2

From Front Wiper Relay 1

From Battery Relay

123567-

Fuse Box A Fuse Box B Front Wiper Motor Front Wiper Relay 1 Front Washer Motor Front Washer Relay

8910111213-

Front Wiper/Washer Switch Rear Wiper/Washer Switch Rear Wiper Motor Rear Washer Motor Rear Wiper Relay Rear Washer Relay

1415161719-

Column Display Controller Intermittent (INT.) Position LOW Position Washer Position Front Wiper Relay 2

T2-5-55

SECTION 2 SYSTEM Group 5 Electrical System Washer Circuit

fNOTE: The operation of front washer is explained here. 1. While front wiper/washer switch (8) is pushed, the circuit from terminal #2-16 in column display controller (14) is connected to the ground through diode H (14) and terminal #6 in front wiper/washer switch (8). 2. The circuit from fuse #4 in fuse box A (1) is connected to the ground through the coil in front washer relay (7), diode H (14), and terminal #6 in front wiper/washer switch (8). 3. When front washer relay (7) is turned ON, current from fuse #4 in fuse box A (1) flows to front washer motor (6) and operates the front washer. 4. At the same time, the circuit from fuse #4 in fuse box A (1) is connected to the ground through slow (21) side of front wiper motor (3), front wiper relay 2 (19), and front wiper relay 1 (5).

fNOTE: While front wiper/washer switch (8) is pushed, washer fluid squirts from front nozzle and front wiper operates at slow speed.

T2-5-56

SECTION 2 SYSTEM Group 5 Electrical System

1 c 7

Fuse#4

6 14 8 17 9 15

a b

2-24 2-23 2-16

2-13 2-14 2-15

2 c Fuse#18

13 TNED-02-05-024 a-

From Front Wiper Relay 2

From Front Wiper Relay 1

From Battery Relay

12356-

Fuse Box A Fuse Box B Front Wiper Motor Front Wiper Relay 1 Front Washer Motor

7891011-

Front Washer Relay Front Wiper/Washer Switch Rear Wiper/Washer Switch Rear Wiper Motor Rear Washer Motor

1213141516-

Rear Wiper Relay Rear Washer Relay Column Display Controller Intermittent (INT.) Position LOW Position

T2-5-57

17192021-

Washer Position Front Wiper Relay 2 Slow Fast

SECTION 2 SYSTEM Group 5 Electrical System Cab Light Circuit Cab Light Switch (4): Door Interlocking Position (5)

Rear Cab Light Switch (8): ON Position

1. When cab light switch (4) is set to door interlocking position (5), the circuit from fuse #3 in fuse box B (1) is connected to door open/close switch (9) through cab lights (2).

1. When the rear cab light switch (8) is set to the ON position, the circuit from fuse #3 in fuse box B (1) is connected to the ground through rear cab light (7).

2. When the cab door is opened, door open/close switch (9) is turned ON and is connected to the ground. 3. Current from fuse #3 in fuse box B (1) flows to door open/close switch (9) and turns on cab lights (2). 4. When the cab door is closed, door open/close switch (9) is turned OFF. Door open/close switch (9) is disconnected from the ground and cab lights (2) are tuned off. 5. When cab light switch (4) is in door interlocking position (5), cab lights (2) are turned on/off by opening/closing the cab door.

fNOTE: Cab light (2) is always on with cab light switch (4) set in ON position (6).

T2-5-58

2. Rear cab light (7) is always turned on with rear cab light switch (8) set in the ON position.

SECTION 2 SYSTEM Group 5 Electrical System

a Fuse#3

From Battery

12-

Fuse Box B Cab Light

45-

Cab Light Switch Door Interlocking Position

67-

T2-5-59

ON Position Rear Cab Light

TNED-02-05-025

89-

Rear Cab Light Switch Door Open/Close Switch

SECTION 2 SYSTEM Group 5 Electrical System (Blank)

T2-5-60

SECTION 3

COMPONENT OPERATION CONTENTS Group 1 Pump Device Outline .................................................................................... T3-1-1 Main Pump ............................................................................ T3-1-2 Regulator ............................................................................... T3-1-4 Pilot Pump ...........................................................................T3-1-18 Pump Delivery Pressure Sensor ...................................T3-1-18

Group 2 Control Valve Outline .................................................................................... T3-2-1 Hydraulic Circuit .................................................................. T3-2-8 Main Relief Valve ...............................................................T3-2-14 Overload Relief Valve (with Make-Up Function) ....T3-2-16 Overload Relief Valve (Lift Arm Bottom Side, Bucket Bottom Side)...................................................T3-2-20 Flow Rate Control Valve ..................................................T3-2-24 Pump Control Valve..........................................................T3-2-26

Group 3 Cooling Fan System Fan Pump ............................................................................... T3-3-1 Fan Motor............................................................................... T3-3-2 Fan Valve ................................................................................ T3-3-3

Group4 Steering Pilot Valve Outline .................................................................................... T3-4-1 Structure ................................................................................ T3-4-2 Operation............................................................................... T3-4-3 Overload Relief Valve ......................................................... T3-4-6 Make-Up Valve ..................................................................... T3-4-8

Group 5 Priority Valve Outline .................................................................................... T3-5-1 Structure ................................................................................ T3-5-2 Operation............................................................................... T3-5-4

Group 6 Pilot Valve Outline (Fingertip Control Type Pilot Valve for Front Attachment)......................................................... T3-6-1 Operation............................................................................... T3-6-2 Electromagnetic Detent ................................................... T3-6-6 Outline (Joystick Type Pilot Valve for Front Attachment) .................................................................... T3-6-7 Operation............................................................................... T3-6-9 Electromagnetic Detent .................................................T3-6-16

Group 7 Brake Charge Valve (Unloader Valve) / Manifold Valve Outline .................................................................................... T3-7-1

Brake Charge Valve (Unloader Valve) ........................... T3-7-2 Manifold Valve...................................................................... T3-7-7 Pilot Relief Valve .................................................................. T3-7-8 Torque Control Solenoid Valve....................................... T3-7-9 Control Lever Lock Solenoid Valve .............................T3-7-11 Service Brake Accumulator ..........................................T3-7-12 Pilot Accumulator .............................................................T3-7-13

Group 8 Drive Unit Outline .................................................................................... T3-8-1 Torque Converter ................................................................ T3-8-6 Transmission ......................................................................... T3-8-8 Operation of Transmission.............................................T3-8-10 Transmission Control Valve ...........................................T3-8-26 Drive Unit Circuit ...............................................................T3-8-28 Parking Brake Manual Release .....................................T3-8-29

Group 9 Axle Outline .................................................................................... T3-9-1 Differential ............................................................................. T3-9-2 Torque Proportioning Differential (TPD) .................... T3-9-6 Limited Slip Differential (LSD) (Option)....................... T3-9-8 Service Brake ......................................................................T3-9-10 Final Drive / Axle Shaft ....................................................T3-9-12

Group 10 Brake Valve Outline ..................................................................................T3-10-1 Operation.............................................................................T3-10-4

Group 11 Ride Control Valve Outline ..................................................................................T3-11-1 Charge-Cut Spool .............................................................T3-11-6 Overload Relief Valve .......................................................T3-11-8 Drain Plug ......................................................................... T3-11-12

Group 12 Others Propeller Shaft ...................................................................T3-12-1 Parking Brake Solenoid Valve Unit..............................T3-12-3 Parking Brake Solenoid Valve .......................................T3-12-4 Parking Brake Accumulator ...........................................T3-12-6 Flow Regulator Valve .......................................................T3-12-7 Steering Accumulator .................................................. T3-12-10 Ride Control Accumulator (Option) ........................ T3-12-10 Torque Converter Cooler Check Valve .................... T3-12-11 Pilot Oil Filter ................................................................... T3-12-12 Secondary Steering Check Block (Option) ............ T3-12-13 Secondary Steering Pump (Option) ........................ T3-12-14

70Z7B F&S (US)

(Blank)

70Z7B F&S (US)

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Outline Hydraulic pump consists of main pump (1) and pilot pump (2). The driving force from the engine is transmitted to shaft (3) through the transmission input shaft and activates main pump (1) and pilot pump (2).

Main pump (1) is a swash-plate type variable displacement axial plunger pump. Pilot pump (2) is a gear pump. The hydraulic pump circuit is equipped with a delivery pressure sensor (4) to read delivery pressures, and also a torque control solenoid valve to control the pump output volume. (Refer to SYSTEM / Control System.)

TNDB-03-01-001

Main Pump

Pilot Pump

T3-1-1

Shaft

Pump Delivery Pressure Sensor

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Main Hydraulic Pump When main pump cylinder block (1) rotates, plungers (2) reciprocate in main pump cylinder block (1) due to angle of swash plate (4), and the pump draws the hydraulic oil up through the pump and delivers the oil out to the hydraulic systems. Regulator (9) controls servo piston 1 (3) and servo piston 2 (6). When the displacement angle of swash plate (4) is changed by servo piston1 (3) and servo piston 2 (6), the stroke of plunger (2) is increased or decreased, so that the delivery flow rate of main pump is regulated.

The main hydraulic pump supplies pressurized oil for operating the cylinders and other hydraulic components. The pump is equipped with a regulator (9) for controlling the delivery flow rate. Shaft (5) is connected to main pump cylinder block (1) so that shaft (5) and main pump cylinder block (1) rotate together.

T4GB-03-01-002

123-

Cylinder Block Plunger Servo Piston 1 (2 Used)

456-

Swash Plate Shaft Servo Piston 2

789-

T3-1-2

Feedback Lever Link Regulator

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Increasing and Decreasing Flow Rate The displacement angle of swash plate (4) is changed by the movement of servo piston 1 (3) and servo piston 2 (6). Movement of the servo pistons is controlled by the regulator. In addition, the displacement angle of swash plate (4) is fed back to the regulator by feedback lever (7) and link (8).

7 8 3 6

fNOTE: Refer to the following pages as for operation of

the regulator.

 Change of Swash Plate Angle 1. The center of swash plate (4) angle is located at point A in the drawings to the right.

T4GB-03-01-022

2. Pilot pressure is always routed to servo piston 2 (6). 3. Therefore, when the circuit of servo piston 1 (3) is connected to the hydraulic tank, swash plate (4) rotates clockwise around A.

4. Conversely, as there are two servo pistons 1 (3) and when pilot pressure is routed to both of servo piston 1 (3) and servo piston 2 (6), swash plate (4) rotates in the opposing direction or counterclockwise around A.

 Feedback Operation 1. End of feedback lever (7) is inserted into protrusion part (D) on the side of swash plate (4).

T4GB-03-01-023

2. When swash plate (4) rotates, protrusion part (D) is also rotated and feedback lever (7) moves together. 3. For example, when swash plate (4) is rotated from the minimum to the maximum, the center of feedback lever (7) is moved from positions B to C as illustrated to the right.

Maximum Tilting:

4. Therefore, link (8) is moved by feedback lever (7) and the movement is fed back to the regulator.

8 7

T4GB-03-01-024 D

T3-1-3

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Regulator The regulator controls the main pump flow rate in response to the various command signal pressures. The major parts of regulator are spring (1), sleeve 1 (2), sleeve 2 (7), spool 1 (3), spool 2 (6), piston (4), load piston (5), inner spring (8), and outer spring (9). The regulator opens and closes the circuit leading to servo piston 1 (10) according to the various command signal pressures, the displacement angle of swash plate (11) is changed and the pump flow rate is regulated.

Pi1

Air

Pi2

14 ST

Pd1

fNOTE: Primary pilot pressure (Pg) is constantly supplied to servo piston 2 (12).

7 Dr 6

8, 9

12 a

b TNDB-03-01-026

Displacement Angle Increase

Pd1- Pump Internal Delivery Pressure ST- Torque Control Pressure Dr- Returning to Hydraulic Tank Air- Air Bleeding Circuit

T3-1-4

Displacement Angle Decrease

Pi1- Pump Control Pressure 1 Pi2- Pump Control Pressure 2 Pg- Primary Pilot Pressure (From Pilot Pump)

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Pump Regulator 13

TNED-03-01-025

Main Piston Pump

TNED-03-01-024

12 1234-

Spring Sleeve 1 Spool 1 Piston

5678-

Load Piston Spool 2 Sleeve 2 Inner Spring

9101112-

T3-1-5

Outer Spring Servo Piston 1 (2 Used) Swash Plate Servo Piston 2

13- Piston 2 14- Piston 1

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Regulator Control Function The regulator has the following three control functions.  Control by Pump Control Pressure When a control lever is operated, the pump flow rate control valve in control valve (housed within the regulator) regulates pump control pressure (Pi1 - Pi2) in response to the control lever stroke. When the regulator receives pump control pressure (Pi1 - Pi2), the regulator controls the pump delivery flow rate in proportion to the pressure. When the control lever is operated, pump control pressure (Pi1 - Pi2) decreases and the regulator increases the pump delivery flow rate. When the control lever is returned to neutral, pump control pressure (Pi1 - Pi2) increases and the regulator decreases the pump delivery flow rate. (Refer to SYSTEM / Hydraulic System.)

0 Q-

Pi1-Pi2

Flow Rate

Pi-

Pump Control Pressure

Q c

 Control by Pumps Internal Delivery Pressure The regulator receives pumps internal delivery pressure Pd1. If the pump pressures increases over the set P-Q line, the regulator reduces pump delivery flow rate and the pump output is returned to the set P-Q line.

QP-

T3-1-6

Flow Rate Pressure

P cd-

Pressure Increase Flow Rate Decrease

SECTION 3 COMPONENT OPERATION Group 1 Pump Device  Control by Pilot Pressure from Torque Control Solenoid Valve MC (Main Controller) calculates the operating conditions of the machine and, using the calculation, the MC sends the pump torque control solenoid the appropriate signal for correct valve. The torque control solenoid valve delivers torque control pressure ST (refer to the next page) to the regulator in response to this signal. The regulator receives pilot pressure and decreases the pump delivery flow rate.

0 Q-

T3-1-7

Flow Rate

P P-

Pressure

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Control by Pump Control Pressure  Flow Rate Decrease 1. When the control lever stroke is reduced, pressure difference arising before and after the flow rate control valve (difference between pressure Pi1 and pressure Pi2) in the control valve is increased.

2. Pump control pressure Pi1 pushes spool 1 (3) through piston 1 (14) and spool 1 (3) moves in the direction of the bold black arrow. 3. Due to this movement, primary pilot pressure Pg is routed to servo piston 1 (10). 4. Two servo pistons 1 (10) are located so that swash plate (11) rotates so as to decrease rate of flow.

0 Q-

Flow Rate

Pi-

Pi1

5. Movement of swash plate (11) is transmitted to sleeve 1 (2) through feedback lever link (15). Sleeve 1 (2) is moved in the same direction as spool 1 (3). 6. When sleeve 1 (2) is moved by the same stroke as spool 1 (3), the open part between sleeve 1 (2) and spool 1 (3) closes and primary pilot pressure Pg routed to servo piston 1 (10) is blocked. Therefore, servo piston 1 (10) is stopped and the flow rate decrease is completed.

Pi1-Pi2

Pump Control Pressure

Pi2 Pg

14 ST

Pd1

15 10

12 a

b TNDB-03-01-026

Displacement Angle Increase

Displacement Angle Decrease

Pd1- Pump Internal Delivery Pressure ST- Torque Control Pressure Dr- Returning to Hydraulic Tank Pi1- Pump Control Pressure 1

Pi2- Pump Control Pressure 2 Pg- Primary Pilot Pressure (From Pilot Pump)

1- Spring 2- Sleeve 1 3- Spool 1 4- Piston 10 - Servo Piston 1

11 - Swash Plate 12 - Servo Piston 2 14 - Piston 1 15 - Feedback Lever Link

T3-1-8

SECTION 3 COMPONENT OPERATION Group 1 Pump Device

3 14

Pi1

Pg Pi2

Pd1

15 12

10 11

Pi1

TNDB-03-01-011

4 1 Pi2

Pd1

10 11

TNDB-03-01-012

Pd1- Pump Internal Delivery Pressure ST- Torque Control Pressure

Dr- Returning to Hydraulic Tank Pi1- Pump Control Pressure 1 Pi2- Pump Control Pressure 2

Pg- Primary Pilot Pressure (From Pilot Pump)

123-

4- Piston 10- Servo Piston 1 11- Swash Plate

12- Servo Piston 2 14- Piston 1 15- Feedback Lever Link

Spring Sleeve 1 Spool 1

T3-1-9

SECTION 3 COMPONENT OPERATION Group 1 Pump Device  Flow Rate Increase 1. When the control lever stroke is increased, pressure difference of the flow rate control valve (difference between pressure Pi1 and pressure Pi2) in the control valve is reduced. Q

2. Force of spring (1) and pump control pressure Pi2 pushes spool 1 (3) through piston (4) so that spool 1 (3) is moved toward in the direction of the bold black arrow. 3. By this movement, the circuit of servo piston 1 (10) is connected to the hydraulic tank. 4. As primary pilot pressure Pg is always supplied to servo piston 2 (12), swash plate (11) is rotated so as to increase the rate of flow. 5. Movement of swash plate (11) is transmitted to sleeve 1 (2) through feedback lever link (15). Sleeve 1 (2) is moved in the same direction as spool 1 (3).

0 Q-

Pi1-Pi2

Flow Rate

6. When sleeve 1 (2) is moved by the same stroke as spool 1 (3), the circuit between servo piston 1 (10) and the hydraulic tank is closed so that servo piston 1 (10) is stopped and the flow rate increase is completed.

Pi-

Pi1

Pump Control Pressure

Pi2 Pg ST

Pd1

15 10

12 a

b TNDB-03-01-026

Displacement Angle Increase

Displacement Angle Decrease

Pd1- Pump Internal Delivery Pressure ST- Torque Control Pressure Dr- Returning to Hydraulic Tank Pi1- Pump Control Pressure 1

Pi2- Pump Control Pressure 2 Pg- Primary Pilot Pressure (From Pilot Pump)

1- Spring 2- Sleeve 1 3- Spool 1 4- Piston 10 - Servo Piston 1

11 - Swash Plate 12 - Servo Piston 2 15 - Feedback Lever Link

T3-1-10

SECTION 3 COMPONENT OPERATION Group 1 Pump Device

3 Pi1

4 1

Pg Pi2

Pd1

15 12

10 11

TNDB-03-01-013

3 Pi1

4 1

Pg Pi2

Pd1 Pd1

15 10

11 TNDB-03-01-014

Pd1- Pump Internal Delivery Pressure ST- Torque Control Pressure

Dr- Returning to Hydraulic Tank Pi1- Pump Control Pressure 1 Pi2- Pump Control Pressure 2

Pg- Primary Pilot Pressure (From Pilot Pump)

123-

4- Piston 10- Servo Piston 1 11- Swash Plate

12- Servo Piston 2 15- Feedback Lever Link

Spring Sleeve 1 Spool 1

T3-1-11

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Control by Pump Internal Delivery Pressure  Flow Rate Decrease 1. When load is applied to the pump by one operation or another, pump internal delivery pressure Pd1 increases. (As done during an operation, pump control pressure (Pi1 - Pi2) remains lowered.)

2. Load piston (5) pushes spool 2 (6), inner spring (8), and outer spring (9) so that spool 2 (6) is moved in the direction of the bold black arrow. 3. By this movement, primary pilot pressure Pg is routed to servo piston 1 (10).

4. Two servo pistons (1) are located so that swash plate (11) is rotated so as to decrease the rate of flow.

Q-

Flow Rate

5. This movement of swash plate (11) is transmitted to sleeve 2 (7) through feedback lever link (15). Sleeve 2 (7) is moved in the same direction as spool 2 (6).

P-

Pi1

Pressure

6. When sleeve 2 (7) is moved by the same stroke as spool 2 (6), the open part between sleeve 2 (7) and spool 2 (6) is closed and primary pilot pressure Pg servo piston 1 (10) is blocked so that causes servo piston 1 (10) is stopped and the flow rate decrease is completed.

Pi2 Pg ST

Pd1

7 Dr 6

11 8, 9 15

12 a

b TNDB-03-01-026

Displacement Angle Increase

Displacement Angle Decrease

Pd1- Pump Internal Delivery Pressure ST- Torque Control Pressure Dr- Returning to Hydraulic Tank Pi1- Pump Control Pressure 1

Pi2- Pump Control Pressure 2 Pg- Primary Pilot Pressure (From Pilot Pump)

56789-

10 - Servo Piston 1 11 - Swash Plate 12 - Servo Piston 2 15 - Feedback Lever Link

T3-1-12

Load Piston Spool 2 Sleeve 2 Inner Spring Outer Spring

SECTION 3 COMPONENT OPERATION Group 1 Pump Device

6 Pi1

Pg Pi2

8 9

Pd1

15 12

10 11

TNDB-03-01-015

6 Pi1

Pg Pi2

8 9

Pd1

10 11

TNDB-03-01-016

Pd1- Pump Internal Delivery Pressure ST- Torque Control Pressure

Dr- Returning to Hydraulic Tank Pi1- Pump Control Pressure 1 Pi2- Pump Control Pressure 2

Pg- Primary Pilot Pressure (From Pilot Pump)

567-

8- Inner Spring 9- Outer Spring 10- Servo Piston 1

11- Swash Plate 12- Servo Piston 2 15- Feedback Lever Link

Load Piston Spool 2 Sleeve 2

T3-1-13

SECTION 3 COMPONENT OPERATION Group 1 Pump Device  Flow Rate Increase 1. When the pump load is reduced, pump internal delivery pressure Pd1 decreases. (As done during an operation, pump control pressure (Pi1 - Pi2) remains lowered.)

2. Load piston (5) and spool 2 (6) are pushed by inner spring (8) and outer spring (9) so that spool 2 (6) is moved in the direction of the bold black arrow. 3. By this movement, the circuit from servo piston 1 (10) is connected to the hydraulic tank. 4. As primary pilot pressure Pg is always supplied to servo piston 2 (12), swash plate (11) is rotated so as to increase the rate of flow.

0 Q-

Flow Rate

5. Movement of swash plate (11) is transmitted to sleeve 2 (7) through feedback lever link (15). Sleeve 2 (7) is moved in the same direction as spool 2 (6).

PDr

Pi1

6. When sleeve 2 (7) is moved by the same stroke as spool 2 (6), the open part between spool 2 (6) and sleeve 2 (7) is closed and the circuit between servo piston 1 (10) and the hydraulic tank is blocked. Therefore, servo piston 1 (10) is stopped and the flow rate increase is completed.

Pressure

Pi2 Pg ST

Pd1

7 Dr 6

11 8, 9 15

12 a

b TNDB-03-01-026

Displacement Angle Increase

Displacement Angle Decrease

Pd1- Pump Internal Delivery Pressure ST- Torque Control Pressure Dr- Returning to Hydraulic Tank Pi1- Pump Control Pressure 1

Pi2- Pump Control Pressure 2 Pg- Primary Pilot Pressure (From Pilot Pump)

56789-

10111215-

T3-1-14

Load Piston Spool 2 Sleeve 2 Inner Spring Outer Spring

Servo Piston 1 Swash Plate Servo Piston 2 Feedback Lever Link

SECTION 3 COMPONENT OPERATION Group 1 Pump Device

Pi1

7 Pi2

8 9 Pd1

15 12 10 11

TNDB-03-01-017

5 Pi1

Pg Pi2

8 9

Pd1

10 11

TNDB-03-01-018

Pd1- Pump Internal Delivery Pressure ST- Torque Control Pressure

Dr- Returning to Hydraulic Tank Pi1- Pump Control Pressure 1 Pi2- Pump Control Pressure 2

Pg- Primary Pilot Pressure (From Pilot Pump)

567-

8- Inner Spring 9- Outer Spring 10- Servo Piston 1

11- Swash Plate 12- Servo Piston 2 15- Feedback Lever Link

Load Piston Spool 2 Sleeve 2

T3-1-15

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Control by Pilot Pressure from Torque Control Solenoid Valve Q

 Flow Rate Decrease 1. When the torque control solenoid valve is activated by the signals from MC (Main Controller), torque control pressure (ST) is routed to the regulator. 2. Torque control pressure ST and pump internal delivery pressure Pd1 are combined and applied to load piston (5). 3. Load piston (5) pushes spool 2 (6), inner spring (8), and outer spring (9), and spool 2 (6) is moved in the direction of the bold black arrow.

0 Q-

Flow Rate

4. By this movement, primary pilot pressure Pg is routed to servo piston 1 (10).

P-

Pi1

Pressure

5. Two servo pistons 1 (10) are located so that swash plate (11) is rotated so as to decrease the rate of flow.

Pi2

6. Movement of swash plate (11) is transmitted to sleeve 2 (7) through feedback lever link (15). Sleeve 2 (7) is moved in the same direction as spool 2 (6).

Pg ST

7. When sleeve 2 (7) is moved by the same stroke as spool 2 (6), the open part between sleeve 2 (7) and spool 2 (6) is closed and primary pilot pressure Pg to servo piston 1 (10) is blocked so that servo piston 1 (10) is stopped and the flow rate decrease is completed.

Pd1

7 Dr 6

11 8, 9 15

12 a

b TNDB-03-01-026

Displacement Angle Increase

Displacement Angle Decrease

Pd1- Pump Internal Delivery Pressure ST- Torque Control Pressure Dr- Returning to Hydraulic Tank Pi1- Pump Control Pressure 1

Pi2- Pump Control Pressure 2 Pg- Primary Pilot Pressure (From Pilot Pump)

56789-

10111215-

T3-1-16

Load Piston Spool 2 Sleeve 2 Inner Spring Outer Spring

Servo Piston 1 Swash Plate Servo Piston 2 Feedback Lever Link

SECTION 3 COMPONENT OPERATION Group 1 Pump Device

6 Pi1

Pg Pi2

8 9 Pd1

TNDB-03-01-019

6 Pi1

Pg Pi2

8 9 Pd1

10 11

TNDB-03-01-020

Pd1- Pump Internal Delivery Pressure ST- Torque Control Pressure

Dr- Returning to Hydraulic Tank Pi1- Pump Control Pressure 1 Pi2- Pump Control Pressure 2

Pg- Primary Pilot Pressure (From Pilot Pump)

567-

8- Inner Spring 9- Outer Spring 10- Servo Piston 1

11- Swash Plate 12- Servo Piston 2 15- Feedback Lever Link

Load Piston Spool 2 Sleeve 2

T3-1-17

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Pilot Pump Drive gear (1) is driven by the engine through the transmission accessory drive, which rotates driven gear (2) as they are meshed together. 1-

Drive Gear

1 2 a

Driven Gear

T137-02-03-005

Inlet Port

Outlet Port

Pump Delivery Pressure Sensor This sensor detects the pump delivery pressures, which are used in order to control various operations. When oil pressure is applied to diaphragm (6), diaphragm (6) flexes slightly. The flexing of diaphragm (6) is detected as electrical signals in ohms. 3 4 5

Ground

Power Source (5V)

Output

Pressure Receiving Area (Diaphragm)

T3-1-18

6 T157-02-03-010

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Outline The 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, pump control valve, flow rate control valve, and spools. The spools are operated by the pilot oil pressure.

Multiple Control Valve

TNDB-03-02-001

b a-

Front Side of Machine

Left Side of Machine

Bucket

Lift Arm

T3-2-1

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Control Valve Hydraulic Circuit

7 TPD8-03-02-001

T3-2-2

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Control Valve Overview

TNDB-03-02-004

123-

Bucket Flow Rate Control Valve Pump Control Valve Overload Relief Valve (Bucket: Bottom Side)

456-

Overload Relief Valve (Bucket: Rod Side) Overload Relief Valve (Lift Arm: Bottom Side) Make-Up Valve (Lift Arm: Rod Side)

789-

Low-Pressure Relief Valve Main Relief Valve Load Check Valve (Lift Arm Circuit) 10- Load Check Valve (Bucket Circuit)

T3-2-3

11- Lift Arm Spool 12- Bucket Spool

SECTION 3 COMPONENT OPERATION Group 2 Control Valve

7 TPD8-03-02-001

T3-2-4

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Control Valve Cross Section View

TNDB-03-02-002

Section A-A 8

TNDB-03-02-006

Section B-B

5 TNDB-03-02-005

1234-

Bucket Flow Rate Control Valve Pump Control Valve Overload Relief Valve (Bucket: Bottom Side) Overload Relief Valve (Bucket: Rod Side)

5678-

Overload Relief Valve (Lift Arm: Bottom Side) Make-Up Valve (Lift Arm: Rod Side) Low-Pressure Relief Valve Main Relief Valve

Load Check Valve (Lift Arm Circuit) 10- Load Check Valve (Bucket Circuit) 11- Lift Arm Spool 12- Bucket Spool

T3-2-5

SECTION 3 COMPONENT OPERATION Group 2 Control Valve

7 TPD8-03-02-001

T3-2-6

SECTION 3 COMPONENT OPERATION Group 2 Control Valve

TNDB-03-02-002

Section C-C 4

TNDB-03-02-007

Section D-D

TNDB-03-02-008

123-

Bucket Flow Rate Control Valve Pump Control Valve Overload Relief Valve (Bucket: Bottom Side)

456-

Overload Relief Valve (Bucket: Rod Side) Overload Relief Valve (Lift Arm: Bottom Side) Make-Up Valve (Lift Arm: Rod Side)

789-

Low-Pressure Relief Valve Main Relief Valve Load Check Valve (Lift Arm Circuit) 10- Load Check Valve (Bucket Circuit)

T3-2-7

11- Lift Arm Spool 12- Bucket Spool

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Hydraulic Circuit Main Circuit The pressurized oil from main pump (8) flows to hydraulic tank (7) through neutral circuit (11) and lowpressure relief valve (6). Parallel circuit (10) is provided in the main circuit and makes the combined operation possible. Pump control valve (1) is provided in the farthest downstream side of neutral circuit (11). Pump control valve (1) delivers pump control pressure to the regulator in response to the operating stroke of the front attachment control lever and controls the pump delivery flow rate. Low-pressure relief valve (6) is provided in the return circuit (between the control valve and the hydraulic tank) of the main circuit. Low-pressure relief valve (6) maintains the specified level pressure in the main circuit and improves the drawing performance of the actuator when cavitation occurs. Main relief valve (9) is provided in the main circuit (between the pump and the actuator). Main relief valve (9) 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 valve (2) is provided in the actuator circuit (between the control valve and the actuator) of lift arm cylinder (3) bottom side and bucket cylinder (5). Overload relief valve (2) prevents the surge pressure caused by the 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 (4) is provided in the actuator circuit (between the control valve and the actuator) of lift arm cylinder (3) rod side. Make-up valve (4) draws the pressurized oil from hydraulic tank (7) and prevents cavitation from occurring when the pressure in the actuator circuit decreases.

T3-2-8

SECTION 3 COMPONENT OPERATION Group 2 Control Valve

12 4 6 7 10

9 TPD8-03-02-002

1234-

Pump Control Valve Overload Relief Valve Lift Arm Cylinder Make-Up Valve

5678-

Bucket Cylinder Low-Pressure Relief Valve Hydraulic Tank Main Pump

9101112-

T3-2-9

Main Relief Valve Parallel Circuit Neutral Circuit Lift Arm Spool

13- Bucket Spool

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Pilot Operation Control Circuit The pressurized oil from the pilot valve acts on the spool in the control valve in order to move the spool.  During bucket dump (Pib2) operation, the pressurized oil moves bucket spool (6).  During lift arm lower (Pib1) operation, the pressurized oil moves lift arm spool (5). Lift arm spool (5) 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.)

T3-2-10

SECTION 3 COMPONENT OPERATION Group 2 Control Valve

3 Pib2

Pia2

Pib1

Pia1

Pia2

Pib2

6 a

b Pib1

Pia1 5

4 TPD8-03-02-003

Pia1- Lift Arm Raise

Pib1- Lift Arm Lower

Lift Arm Lower

Lift Arm Float

12-

Bucket Pilot Valve Lift Arm Pilot Valve

34-

Pilot Pump Control Valve

Pia2- Bucket Roll Back

56-

T3-2-11

Lift Arm Spool Bucket Spool

Pib2- Bucket Dump

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Lift Arm Float Control Operation: 1. If lift arm lower (Pib1) is fully stroked, the lift arm control lever is hold in the stroke end due to the electromagnetic detent of the pilot valve. 2. Pressurized oil (Pib1) from the pilot valve moves lift arm spool (2) to the left. 3. Therefore, the pressurized oil in the rod and bottom sides of lift arm cylinder (1) flow to hydraulic tank (4). 4. Consequently, the lift arm can move freely depending on the external force. (Refer to Control System.)

T3-2-12

SECTION 3 COMPONENT OPERATION Group 2 Control Valve

Pib1 2

T4FC-03-02-012

Pib1

T4FC-03-02-010

4 Pib1- Lift Arm Lower 1-

Lift Arm Cylinder

Lift Arm Spool

T3-2-13

Main Pump

Hydraulic Tank

SECTION 3 COMPONENT OPERATION Group 2 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. The 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 the pressure in port HP reaches the set pressure of spring B (6), pilot poppet (8) is opened, the pressurized oil from passage A (5) flows to port LP (hydraulic 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 the pressurized 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).

T3-2-14

SECTION 3 COMPONENT OPERATION Group 2 Control Valve During Normal Operation: 1

TNED-03-02-013

During Relief Operation: 3

HP- Main Circuit

LP- Hydraulic Tank

123-

456-

Main Poppet Orifice A Orifice B

Seat Passage A Spring B

8- Pilot Poppet 9- Spring A 10- Spring Chamber

T3-2-15

TNED-03-02-014

11- Sleeve

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Overload Relief Valve (with Make-Up Function) The overload relief valve is located in the lift arm raise and bucket circuits. 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 pressurized oil from the hydraulic tank and prevents the occurrence of cavitation (make-up function). Over Load Relief Valve (Bucket: Rod Side) Relief Operation 1. The pressure in port HP (actuator circuit) is routed to pilot poppet (8) through orifice (1) of piston (3). 2. When the pressure in port HP reaches the set pressure of spring B (6), pilot poppet (8) is opened, pressurized oil from passage A (5) flows to port LP (hydraulic 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 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, piston (3) and main poppet (2) are closed by the force of spring A (4).

T3-2-16

SECTION 3 COMPONENT OPERATION Group 2 Control Valve During Normal Operation: 2

T4GB-03-02-030

During Relief Operation: 2

HP- Actuator Circuit

LP- Hydraulic Tank

123-

456-

Orifice Main Poppet Piston

Spring A Passage A Spring B

T4GB-03-02-031

789-

T3-2-17

Spring C Pilot Poppet Spring Chamber

10- Sleeve

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Overload Relief Valve (Bucket: Rod Side) Make-Up Operation 1. When the pressure in port HP (actuator circuit) decreases lower than the pressure in port LP (hydraulic tank), sleeve (10) is moved to the right. 2. Hydraulic oil in port LP flows to port HP and cavitation is prevented. 3. When the pressure in port HP increases to the specified pressure, sleeve (10) is closed by the force of spring C (7).

T3-2-18

SECTION 3 COMPONENT OPERATION Group 2 Control Valve During Make-Up Operation: 10

LP 7 T4GB-03-02-032

HP- Actuator Circuit

LP- Hydraulic Tank

10- Sleeve

Spring C

T3-2-19

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Overload Relief Valve (Lift Arm Bottom Side, Bucket Bottom Side) Relief Operation 1. The pressure in port HP (actuator circuit) is routed to shaft (2) through the inner passage in seat (1). 2. When the pressure in port HP reaches the set pressure of spring A (4), shaft (2) is moved and pressurized oil flows to port LP (hydraulic tank). 3. Consequently, the actuator circuit pressure decreases. 4. When the actuator circuit pressure decreases to the specified level, shaft (2) is moved to the right by the force of spring A (4) and the oil passage is closed.

T3-2-20

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Normal Operation: 1

2 HP

TNEJ-03-02-001

TNEJ-03-02-002

During Relief Operation: 1

HP- Actuator Circuit

LP- Hydraulic Tank

Seat

Shaft

T3-2-21

Spring B

Spring A

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Overload Relief Valve (Lift Arm Bottom Side, Bucket Bottom Side) Make-Up Operation 1. When the pressure in port HP (actuator circuit) decreases lower than the pressure in port LP (hydraulic tank) and reaches the set force of spring B (3), seat (1) is moved to the right. 2. Hydraulic oil in port LP flows to port HP and cavitation is prevented. 3. When the pressure in port HP increases to the specified pressure, seat (1) is closed by the force of spring B (3).

T3-2-22

SECTION 3 COMPONENT OPERATION Group 2 Control Valve During Make-Up Operation: 1

HP- Actuator Circuit

LP- Hydraulic Tank

Seat

Shaft

TNEJ-03-02-003

T3-2-23

Spring B

Spring A

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Flow Rate Control Valve The flow rate control valve consists of check valve (6) and orifice (7). The flow rate control valve is provided in the bucket spool (8) side of parallel circuit (4). It restricts the bucket side circuit during combined operation and keeps the higher load operation of lift arm.

4 6

 During Combined Operation of Lift Arm Raise and Bucket Roll Back: 1. One pressurized oil from main pump (12) flows lift arm spool (3) through load check valve (2) and moves lift arm cylinder (9).

2. Other pressurized oil flows to parallel circuit (4), flows to bucket spool (8) through the flow rate control valve, and moves bucket cylinder (10).

3. The pressurized oil which flows to bucket spool (8) pushers to open check valve (6), flows to orifice (7), and is regulated. 4. Therefore, more pressurized oil is supplied to the higher load lift arm side circuit. 5. Consequently, the operation of bucket roll back and lift arm raise are performed at the same time.

13 T4GB-03-02-020

456-

T3-2-24

Parallel Circuit Load Check Valve Check Valve (Flow Rate Control Valve)

Orifice (Flow Rate Control Valve) 8- Bucket Spool 13- Neutral Circuit

SECTION 3 COMPONENT OPERATION Group 2 Control Valve

Pia2

Pia1 4 3

11 2

12 13 TPD8-03-02-004

Pia1- Lift Arm Raise (Pilot Pressurized Oil)

Pia2- Bucket Roll Back (Pilot Pressurized Oil)

1234-

56-

Control Valve Load Check Valve Lift Arm Spool Parallel Circuit

Load Check Valve Check Valve (Flow Rate Control Valve)

789-

T3-2-25

Orifice (Flow Rate Control Valve) Bucket Spool Lift Arm Cylinder

10111213-

Bucket Cylinder Hydraulic Tank Main Pump Neutral Circuit

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Pump Control Valve The pump control valve consists of orifice (1) and surge pressure relief valve (2). It is provided in the farthest downstream side of neutral circuit (3). The pump control valve controls the pump control pressure according to the control lever stroke. Pump regulator (5) increases and decreases the pump delivery flow rate according to this pump control pressure. (Refer to SYSTEM / Hydraulic System.)

Pc2

Operation  When the control lever is in neutral 1. Pressurized oil (c) from main pump (6) flows to neutral circuit (3) and flows back to hydraulic tank (8) through orifice (1). Pc1

2. The pressure difference between pump control pressure Pc1 before of orifice (1) and Pc2 after it is routed to pump regulator (5) as the pump control pressure. 3. When the flow rate of pressurized oil (c) flowing through neutral circuit (3) increases, the pump control pressure (pressure difference between Pc1 and Pc2) is increased by orifice (1).

4. Therefore, pump regulator (5) decreases the pump delivery flow rate.

Pc2

5. When the neutral circuit (3) pressure continues to increase, surge pressure relief valve (2) is opened. Pressurized oil (c) flows back to hydraulic tank (8) through orifice (1) and surge pressure relief valve (2).

6. Therefore, the surge pressure in neutral circuit (3) is prevented.  When the control lever is operated 1. As pressurized oil (c) from main pump (6) flows to spools (9, 10), the flow rate of neutral circuit (3) is decreased.

TNEJ-03-02-004

Pc1- Pump Control Pressure Pc2- Pump Control Pressure

Pressurized Oil from Pump (Neutral Circuit)

Surge Pressure Relief Valve

2. Therefore, as the pressure difference decreases, the pump control pressure (pressure difference between Pc1 and Pc2) is decreased. 3. Therefore, pump regulator (5) increases the pump delivery flow rate.

T3-2-26

Orifice

SECTION 3 COMPONENT OPERATION Group 2 Control Valve

Pc2

Pc1

8 7

6 8 X1

TPD8-03-02-005

Pc2

5 Pc1 PS2

Pc1- Pump Control Pressure Pc2- Pump Control Pressure

X1- Torque Control Pressure ST (from Torque Control Solenoid Valve)

PS2- Primary Pilot Pressure (Pressurized Oil from Pilot Pump)

12-

345-

678-

Orifice (Pump Control Valve) Surge Pressure Relief Valve (Pump Control Valve)

Neutral Circuit Control Valve Pump Regulator

T3-2-27

Main Pump Pilot Pump Hydraulic Tank

9- Lift Arm Spool 10- Bucket Spool 11- Low-Pressure Relief Valve

SECTION 3 COMPONENT OPERATION Group 2 Control Valve (Blank)

T3-2-28

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System Fan Pump Fan pump (1) is a gear pump and is directly connected to the engine. Fan pump (1) supplies pressurized oil to the fan motor and fan valve.

TDAB-03-07-006

Inlet Port

Fan Pump

Outlet Port

T3-3-1

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System 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 fan pump, plunger (6) is pushed. Since swash plate (3) is angled, shoe (4) on the end of plunger (6) slides along swash plate (3) and rotor (1) turns. 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-

T3-3-2

Retainer Plunger

key

TNED-03-03-009

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System Fan Control Valve The fan control valve 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 the Main Controller (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 returns pressurized oil to the hydraulic 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.

4 3

TNED-03-03-001

AB-

Port A Port B

PS-

Port P Port S

T-

Port T

Fan Speed Control Solenoid Valve

Fan Reverse Rotation Control Solenoid Valve

34-

Fan Control Valve Fan Reverse Rotation Spool

T3-3-3

Dr- Drain Port

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System Normal Operation 1. Pressurized oil from port P splits into three circuits. 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 in the direction of the heavy black arrow.

1 B

3. Pressurized oil from port P flows to the fan motor through the periphery of fan reverse rotation spool (2) and port A.

4. Therefore, the fan rotates in normal direction. P

TNED-02-04-035

PTDrA-

From Pilot Pump To Hydraulic Tank To Hydraulic 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

T3-3-4

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System  Normal Rotation

4 P

2 3

TNED-03-03-005

PT-

From Pilot Pump To Hydraulic Tank

Dr- To Hydraulic 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

T3-3-5

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System 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 the Main Controller. (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 Tank Dr- To Hydraulic Tank

268-

T3-3-6

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 3 Cooling Fan System  Reverse Rotation 8

TNED-03-03-006

PT-

From Pilot Pump To Hydraulic Tank

Dr- To Hydraulic Tank

A-

To Fan Motor (Normal Rotation Side)

Fan Reverse Rotation Spool

Spool

Fan Reverse Rotation Control Solenoid Valve

T3-3-7

B-

To Fan Motor (Reverse Rotation Side)

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System Fan Speed Control 1. The Main Controller (MC) activates fan speed control solenoid valve (7) according to coolant temperature, torque converter oil temperature, hydraulic oil temperature, etc. (Refer to SYSTEM / Control System.) 2. Therefore, the spring (4) chamber is connected to port Dr or drain, returning oil to the hydraulic tank. 3. Pressurized oil in the spring (4) chamber flows to port Dr to the hydraulic tank through orifice (11), passage (9), and the spool (10) of fan speed control solenoid valve (7).

9 B

10 T

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 in the direction of the bold black arrow and pressurized oil from port P flows to port T (hydraulic tank).

6. Pressurized oil flowing to the fan motor decreases and the fan speed slows.

TNED-02-04-036

7. This action permits the fan to rotate at the best speed. 8. In addition, pressurized oil in the spring (4) chamber flows to port Dr (hydraulic tank) through orifice (11) in a manner that slowly bleeds it of, and permits the action to have a modulation effect. 9. Therefore, the fan speed is prevented from changing suddenly.

P- From Pilot Pump T- To Hydraulic Tank Dr- To Hydraulic Tank

A-

457-

10- Spool 11- Orifice

T3-3-8

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 3 Cooling Fan System  Fan Speed Control

4 P

3 9 Dr

TNED-03-03-007

PT-

From Pilot Pump To Hydraulic Tank

Dr- To Hydraulic Tank

A-

345-

Poppet Spring Fan Control Valve

11- Orifice

Fan Speed Control Solenoid Valve 9- Passage 10- Spool

T3-3-9

To Fan Motor (Normal Rotation Side)

B-

To Fan Motor (Reverse Rotation Side)

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System Make-Up Function The make-up valve keeps the hydraulic fan drive from developing what are known as cavitation ("voids" or vacuum pockets) when slowing down or while reversing the fan rotation. Sudden decreases in rpm’s (min-1) can cause voids (cavitation) to occur, and these voids would produce a symptom of delays in response to directional changes or delays in changes in fan speed. If a make-up valve sticks closed, these delays can occur. If it were to stick in the open position, the speed in a given direction would be affected, making the fan rotate much more slowly than normal when that direction is selected. The following explains the make up function. 1. When pressure at port A or port B is lower than pressure at port T (hydraulic 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. 12

TNED-03-03-008

T-

To Hydraulic Tank

12- Check Valve

A-

To Fan Motor (Normal Rotation Side)

B-

13- Spring

T3-3-10

To Fan Motor (Reverse Rotation Side)

SECTION 3 COMPONENT OPERATION Group4 Steering Pilot Valve Outline Steering pilot valve is located between the priority valve and the steering cylinder. Steering pilot valve supplies pressurized oil from the main pump to the steering cylinder 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 Tank)

T3-4-1

Port LS

SECTION 3 COMPONENT OPERATION Group4 Steering Pilot Valve 11

Structure

Steering pilot valve consists of 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 opened between spool (4) and sleeve (3). Pressurized oil from the main 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

6 T4FC-03-04-002 1234-

Housing Centering Spring Sleeve Spool

5678-

Pin Plate Drive Gerotor

9101112-

T3-4-2

Spacer Cap Check Valve Hole

13- Load Check Valve

SECTION 3 COMPONENT OPERATION Group4 Steering Pilot Valve Operation Sleeve (3), spool (4), and drive (7) are all connected to each other 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. 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

TNDB-03-04-007

T4FC-03-04-003

Steering Wheel

T3-4-3

SECTION 3 COMPONENT OPERATION Group4 Steering Pilot Valve Steering (Left) 1. When the steering wheel is rotated left, spool (4) rotates, and pressurized oil from main pump (15) flows in the order of port P - sleeve (3) - spool (4) sleeve (3) - housing (1) - gerotor (8).

4. When pressurized oil from main pump (15) enters gerotor (8), gerotor (8) rotates left. The rotation of gerotor (8) is transmitted to sleeve (3) through drive (7) and sleeve (3) rotates left similarly.

2. Pressurized oil from gerotor (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 machine body left.

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.

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 tank.

6. Therefore, gerotor (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.

15 1 8 7

4 123-

Housing Centering Spring Sleeve

478-

2 Spool Drive Gerotor

T4FC-03-04-004

3 13- Steering Cylinder 14- Steering Pilot Valve 15- Main Pump

T3-4-4

SECTION 3 COMPONENT OPERATION Group4 Steering Pilot 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 machine body right.

2. Returning oil from the steering cylinder flows in the order of port L - port T and returns to the hydraulic 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.

T3-4-5

TNDB-03-04-011

SECTION 3 COMPONENT OPERATION Group4 Steering Pilot Valve 8

Overload Relief Valve

Overload relief valve (4) consists of poppet (2) and spring (3), and is located in steering pilot valve (1). When spool (7) is in the neutral position, overload relief valve (4) prevents pressure in the circuit (between steering pilot valve and steering cylinder) due to surge pressure developed by external force from exceeding the set pressure.

6 L

Relief Operation 1. When the pressure in the circuit (between steering pilot valve and steering cylinder) exceeds the spring 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 hydraulic tank (10) through port T.

7 T

10 TNDB-03-04-006

1467-

T3-4-6

Steering Pilot Valve Overload Relief Valve Make-Up Valve Spool

8- Steering Cylinder (Left) 9- Steering Cylinder (Right) 10- Hydraulic Tank

SECTION 3 COMPONENT OPERATION Group4 Steering Pilot Valve

Section A-A

T4FC-03-04-011

A T4FC-03-04-009

12-

Steering Pilot Valve Poppet

34-

Spring Overload Relief Valve

T3-4-7

SECTION 3 COMPONENT OPERATION Group4 Steering Pilot Valve 8

Make-Up Valve

Make-up valve (6) is located in steering pilot valve (1). Make-up valve (6) draws pressurized oil from hydraulic tank (10) and prevents cavitation from occurring when the pressure in the circuit (between steering pilot valve and steering cylinder) decreases below the specified value. 6

Relief Operation 1. When the pressure in the circuit (between steering pilot valve and steering cylinder) decreases below the pressure in hydraulic tank (10), ball (5) of makeup valve (6) moves right. 2. Therefore, the oil passage is connected to port T. Pressurized oil from hydraulic tank (10) is drawn through port T and flows to the circuit.

7 T

10 TNDB-03-04-006

1467-

T3-4-8

Steering Pilot Valve Overload Relief Valve Make-Up Valve Steering Spool

8- Steering Cylinder (Left) 9- Steering Cylinder (Right) 10- Hydraulic Tank

SECTION 3 COMPONENT OPERATION Group4 Steering Pilot 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

D 5T4FC-03-04-010

T3-4-9

Ball

Make-Up Valve

SECTION 3 COMPONENT OPERATION Group4 Steering Pilot Valve (Blank)

T3-4-10

SECTION 3 COMPONENT OPERATION Group 5 Priority Valve Outline Priority valve (1) supplies pressurized oil from the main pump to the steering pilot valve and the control valve in response to the movement of the steering pilot valve. (Refer to SYSTEM / Hydraulic System.) Main relief valve (2) prevents the pressure in the circuit (between main pump and steering pilot valve) from increasing over the set pressure while operating the steering wheel.

TNDB-03-05-001 P

P- From Main Pump CF- To Steering Pilot Valve

EF- To Control Valve LS- To Steering Pilot Valve

Priority Valve

T-

Main Relief Valve

T3-5-1

To Hydraulic Tank

SECTION 3 COMPONENT OPERATION Group 5 Priority Valve Structure Priority valve (1) consists of main relief valve (2), spool (5), spring (3), and orifices (4, 6). Spool (5) is pushed left by spring (3) with the engine stopped. Port P is connected to the main pump and port CF is connected to the steering pilot valve. Port EF is connected to the control valve. NOTE: The illustration on the right shows the spool (5) position with the engine stopped.

T3-5-2

SECTION 3 COMPONENT OPERATION Group 5 Priority Valve 1

TNDB-03-05-001

P- From Main Pump CF- To Steering Pilot Valve

EF- To Control Valve LS- To Steering Pilot Valve

T-

To Hydraulic Tank

12-

34-

56-

Spool Orifice A

Priority Valve Main Relief Valve

Spring Orifice B

T3-5-3

TNDB-03-05-002

SECTION 3 COMPONENT OPERATION Group 5 Priority Valve Operation When steering is in neutral 1. Pressurized oil from main 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 main 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 tank (18) through 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 main pump (9) is supplied to the control valve through port EF.

T3-5-4

SECTION 3 COMPONENT OPERATION Group 5 Priority Valve 10

12 L

14 15 19

18 P1

a CF

18 TNDB-03-05-003

P- Port P CF- Port CF P1- Port P1

EF- Port EF a- To Control Valve LS- Port LS

TLR-

Port T Port L Port R

12345-

678910-

1112131415-

Steering Cylinder (Right) Steering Pilot Valve Gerotor Steering Spool Steering Wheel

Priority Valve Chamber A Orifice A Spool Chamber B

Orifice B Spring Main Relief Valve Main Pump Steering Cylinder (Left)

T3-5-5

16171819-

Orifice (Variable) Sleeve Hydraulic Tank Orifice (Variable)

SECTION 3 COMPONENT OPERATION Group 5 Priority Valve When steering is operated

f NOTE: Orifice (16) of steering pilot valve (12) is a

variable orifice and the opening area of it is changed in proportion to the amount of stroke of steering wheel (15).

1. When steering wheel (15) is rotated, spool (14) of steering pilot valve (12) moves and orifices (16, 19) are opened. 2. Pressurized oil in the circuit between chamber A (2) in priority valve (1) and orifices (16, 19) in steering pilot valve (12) flows to gerotor (13). 3. When pressurized oil flows to gerotor (13), the pressure in the circuit between chamber A (2) in priority valve (1) and orifices (16, 19) in steering pilot valve (12) through port CF decreases. Then, spool (4) of priority valve (1) moves left. 4. Spool (4) of priority valve (1) stops at the position where pressurized oil equivalent to the open amount of orifices (16, 19) flows to steering pilot valve (12). 5. At this time, pressurized oil from main pump (9) flows to both steering pilot valve (12) and the control valve through spool (4) of priority valve (1). 6. Pressurized oil from main pump (9) flows to gerotor (13) through spool (14) and sleeve (17) of steering pilot valve (12). 7. Gerotor (13) delivers pressurized oil as a hydraulic motor. This pressurized oil flows to steering cylinders (10, 11) at right and left and the machine turns.

f NOTE: The illustration on the right shows the oil flow when steering wheel (15) is rotated right.

T3-5-6

SECTION 3 COMPONENT OPERATION Group 5 Priority Valve 10

12 L

13 14 15

19 T

16 P1 a CF

18 TNDB-03-05-004

P- Port P CF- Port CF P1- Port P1

EF- Port EF a- To Control Valve LS- Port LS

TLR-

Port T Port L Port R

12345-

678910-

1112131415-

Steering Cylinder (Right) Steering Pilot Valve Gerotor Steering Spool Steering Wheel

Priority Valve Chamber A Orifice A Spool Chamber B

Orifice B Spring Main Relief Valve Main Pump Steering Cylinder (Left)

T3-5-7

16171819-

Orifice (Variable) Sleeve Hydraulic Tank Orifice (Variable)

SECTION 3 COMPONENT OPERATION Group 5 Priority Valve When steering cylinder is at stroke end 1. Pressurized oil from port P1 of steering pilot valve (12) is divided in spool (14), flows to gerotor (13) and port LS of priority valve (1) through orifices (16, 19), and is routed to chamber B (5). 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, main relief valve (8) in priority valve (1) is activated. 4. Therefore, pressurized oil routed to chamber B (5) flows to hydraulic tank (18) through main 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 main pump (9) flows to the control valve through spool (4) of priority valve (1) and port EF. 8. Therefore, more pressurized oil is supplied to the control valve through port EF 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 is equal to the set pressure of main relief valve (8).

T3-5-8

SECTION 3 COMPONENT OPERATION Group 5 Priority Valve 10

12 L

13 14 15

19 16 18 P1 a CF

18 TNDB-03-05-005

P- Port P CF- Port CF P1- Port P1

EF- Port EF a- To Control Valve LS- Port LS

TLR-

Port T Port L Port R

12345-

678910-

1112131415-

Steering Cylinder (Right) Steering Pilot Valve Gerotor Steering Spool Steering Wheel

Priority Valve Chamber A Orifice A Spool Chamber B

Orifice B Spring Main Relief Valve Main Pump Steering Cylinder (Left)

T3-5-9

16171819-

Orifice (Variable) Sleeve Hydraulic Tank Orifice (Variable)

SECTION 3 COMPONENT OPERATION Group 5 Priority Valve (Blank)

T3-5-10

SECTION 3 COMPONENT OPERATION Group 6 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 control valve. The pilot valve delivers pilot pressurized oil in proportion to the control lever stroke. This is done by using a Pressure Proportional Control (PPC) Valve which moves the spool in the control valve. Port No. 1 2 3 4

Bucket Dump Bucket Roll Back Lift Arm Lower Lift Arm Raise

Hydraulic Symbol

P T 2

3 T4GB-03-05-001 P

PT-

T3-6-1

Port P (Pressurized Oil from Pilot Pump) Port T (To Hydraulic Tank)

T4GB-03-05-002

SECTION 3 COMPONENT OPERATION Group 6 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 from port P. Also, output port (Y) is connected to tank port (T) through notch part (Z) of spool (7), and the pressurized oil in output port (Y) 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 push rod (3) are pushed in. Push rod (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 the clearance (X) becomes zero.

T523-02-05-001 a-

4. During this movement, output port (Y) remains connected with tank port (T), and pressurized oil is not supplied to output port (Y).

fNOTE: Lever stroke during the period when the

clearance (X) becomes zero is the play of the control lever.

T3-6-2

Pilot Pressure

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve

1 2

4 5 6 T X

X Z

7 Y

T4GB-03-05-004

T4GB-03-05-003

P-

Pilot Pressure Port

T-

Tank Port

X-

Clearance

Z-

Notch Part

12-

Lever Push Rod

34-

Push Rod Spring Guide

Y-

Output Port

56-

Balance Spring Return Spring

T3-6-3

Spool

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve While Metering Pilot Oil (Output Curve: C to D)

Full Stroke (Output Curve: E to F)

1. When the control lever is further tilted, output port (Y) is connected with pilot pressure port (P) through spool (7).

1. When the control lever is fully stroked, push rod (3) moves downward until spring guide (4) contacts the shoulder part of the casing.

2. Pressurized oil from Port P flows into output port (Y) through spool (7), and the pressure in output port (Y) is raised.

2. At this time, spool (7) is directly pushed by the bottom of push rod (3). Therefore, output port (Y) remains connected to the port P through notch part (Z) of spool (7) because even if the pressure at the output port is raised, spool (7) does not move upward.

3. Pressure in output port (Y) works spool (7), and tends to push up spool (7). 4. In case the force to push up spool (7) is less than the balance spring (5) force, balance spring (5) does not compress. The port P and output port (Y) remain connected, and the pressure in output port (Y) keeps rising.

3. As a result, the pressure at the output port end is equal to the pressure at port P. Stroke amount C of the stem determines the total stroke of the lever.

5. When the pressure in output port (Y) rises the force to push spool (7) up increases. If this force overcomes the balance spring (5) force, spool (7) moves upwards, compressing balance spring (5).

6. When spool (7) moves upward, output port (Y) is not connected any longer, and pressurized oil stops flowing from port P to output port (Y). And pressure in output port (Y) stops increasing. C

7. In this way, balance spring (5) is compressed in proportion to the amount spool (7) is pushed down, and the pressure in output port (Y) is the balanced pressure working on the spring force and spool (7).

T523-02-05-001 a-

T3-6-4

Pilot Pressure

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve

4 Z P

P-

Pilot Pressure Port

Z-

Notch Part

Push Rod

T4GB-03-05-005

T-

Tank Port

Y-

Output Port

Spring Guide

Balance Spring

T3-6-5

Spool

T4GB-03-05-006

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve Electromagnetic Detent 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 opposite side are pushed upwards by the spring force. 3. If the control lever is fully stroked, plate (8) of the opposite side (forced up side) is held by electromagnetic coil assembly (10). This holds the control lever at it’s position. 4. This electromagnetic attraction between coil assembly (10) and plate (8) continues until coil assembly (10) is deenergized or until the magnetic force is forcibly separated by operating the control lever toward the neutral direction with enough force to overcome the power of detents.

90T4GB-03-05-07

Push Rod

Plate

10 - Coil Assembly

T3-6-6

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve (Blank)

T3-6-7

SECTION 3 COMPONENT OPERATION Group 6 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 control valve. The pilot valve delivers pilot pressurized oil in proportion to the control lever stroke. This is done by using a Pressure Proportional Control (PPC) Valve which moves the spool in the control valve. Port No. 1 2 3 4

Lift Arm Lower Bucket Dump Lift Arm Raise Bucket Roll Back

Hydraulic Symbol

P T 3

2 T4GB-03-05-001

PT-

T3-6-8

Port P (Pressurized Oil from Pilot Pump) Port T (To Hydraulic Tank)

TNED-03-06-002

SECTION 3 COMPONENT OPERATION Group 6 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 (X) of stem (2).

2 4 7

6 8 3 TNED-03-06-003

12-

Cam Stem

34-

Case Spring Guide

56-

T3-6-9

Balance Spring Return Spring

78-

Spool Hole

SECTION 3 COMPONENT OPERATION Group 6 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, output port (Y) is opened to the tank port (T) (hydraulic tank) through the inner passage in the lower part of spool (7).

2. Therefore, pressure in output port (Y) is equal to the pressure of the tank port (T). 3. When the control lever is slightly tilted, cam (1) is tilted and stem (2) is pushed downward. Stem (2) compresses return spring (6) along with spring guide (4) together.

4. At this time, as pressure in output port (Y) is equal to that in the tank port T, spool (7) moves downward due to the balance spring (5) force that is caged between spring guide (4) and spool (7). Note that the lower surface of the upper head of spool (7) remains in contact with spring guide (4).

T523-02-05-001 a-

5. This downward movement of spool (7) and port alignment continue until hole (8) on spool (7) is connected to port P.

T3-6-10

Pilot Pressure

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve

4 7

3 P

TNED-03-06-003

P-

Pilot Pressure Port

T-

Tank Port

Y-

Output Port

12-

Cam Stem

34-

Case Spring Guide

56-

Balance Spring Return Spring

T3-6-11

78-

TNED-03-06-004

Spool Hole

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve While Metering Pilot Oil (Output Curve: C to D) 1. When the control lever is further tilted and stem (2) is moved further downward, hole (8) on spool (7) is connected to port P and pressurized oil in port P flows to output port (Y).

2. Pressure in output port (Y) is routed to the bottom surface of spool (7) so that spool (7) is pushed upward. This upward force is seen by the operator as lever feedback pressure, and contributes to operational feel and hydraulic pilot modulation.

3. When the force to move spool (7) upward is less than the balance spring (5) force, balance spring (5) does not compress. The result is that spool (7) does not raise and pressure in output port (Y) increases. 4. As pressure in output port (Y) increases 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) moves upward, hole (8) is closed so that pressurized oil from port P stops flowing to output port (Y) and pressure in output port (Y) stops increasing. 6. As spool (7) moves downward and balance spring (5) is compressed, pressure routed to the bottom surface of spool (7) increases until pressure balances with the increasing spring force. This increasing pressure is equal to the pressure in output port (Y).

T3-6-12

Pilot Pressure

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve

4 7

3 P

TNED-03-06-005

P-

Pilot Pressure Port

T-

Tank Port

Y-

Output Port

12-

Cam Stem

34-

Case Spring Guide

56-

Balance Spring Return Spring

T3-6-13

78-

TNED-03-06-006

Spool Hole

SECTION 3 COMPONENT OPERATION Group 6 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) is greater than pressure in output port (Y) (force to push spool (7) upward).

2. Therefore, even if pressure in output port (Y) increases further, hole (8) on spool (7) remains open. 3. Consequently, pressure in output port (Y) is equal to that in port P.

T523-02-05-001 a-

T3-6-14

Pilot Pressure

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve

2 4 7

6 8 3 P

TNED-03-06-007

P-

Pilot Pressure Port

T-

Tank Port

Y-

Output Port

12-

Cam Stem

34-

Case Spring Guide

56-

Balance Spring Return Spring

T3-6-15

78-

Spool Hole

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve Electromagnetic Detent 1. The coil for detent is installed inside the pilot valve. 2. If the control lever is fully stroked, plate (9) is held by electromagnetic coil assembly (10). 3. This electromagnetic attraction between coil assembly (10) and plate (9) continues until coil assembly (10) is deenergized or until the magnetic force is forcibly separated by the operator by means of physically overpowering the magnetic force on the control lever.

TNED-03-06-007

Plate

10- Coil Assembly

T3-6-16

SECTION 3 COMPONENT OPERATION Group 7 Brake Charge Valve / Manifold Valve Outline The charging circuit consists of brake charge valve (unloader valve) (3) and manifold valve (1). (Refer to SYSTEM/Hydraulic System.) Brake charge valve (unloader valve) (3) supplies the pressurized oil from the pilot pump preferentially to service brake accumulator (5), the brake valve, and the parking brake. In addition, brake charge valve (unloader valve) (3) also supplies pressurized oil to manifold valve (1). Pressure sensor (brake primary pressure) (4) for the brake oil low pressure indicator is installed in brake charge valve (unloader valve) (3).

Manifold valve (1) supplies the pressurized oil from brake charge valve (unloader valve) (3) to the, pump regulator, and ride control valve. In addition, when the control lever lock solenoid valve is shifted, manifold valve (1) also supplies the pressurized oil to the pilot valve. Pressure sensor (primary pilot pressure) (2) for the control lever lock indicator is installed in manifold valve (1).

1 2

TNDB-03-07-014

12-

Manifold Valve Pressure Sensor (Primary Pilot Pressure)

34-

Brake Charge Valve (Unloader Valve) Pressure Sensor (Brake Primary Pressure)

56-

T3-7-1

Service Brake Accumulator (2 Used) Pilot Accumulator (Front Attachment)

SECTION 3 COMPONENT OPERATION Group 7 Brake Charge Valve / Manifold Valve Brake Charge Valve (Unloader Valve) The brake charge valve (unloader valve) consists of priority valve (12), spool (3), and pilot piston (7).

Operation  Between pressure accumulation start and finish 1. When the pressure of the brake circuits (service brake accumulators (17, 18)) decrease, the passage (5) pressure also decreases. Pilot piston (7) and piston (6) are moved down (up on the circuit diagram) by the spring (8) force.

4 5 6 7

d 19 15

2. Therefore, the passage (14) pressure increases slowly as passage (14) and port T are blocked by pilot piston (7).

14 13

8 9 10

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 (12) moves to the right.

4. The pressurized oil from port P pushes to open check valve (9) and flows to service brake accumulators (17, 18) and the brake circuits.

11 TNED-03-07-015

5. At this time, in case the pressure difference is generated in the front and rear brake circuits, spool (3) moves to the pressure-low side. 6. Therefore, the pressurized oil is supplied to the pressure-low circuit preferentially. 7. When the brake circuit pressure decreases, priority valve (12) is moved to the right by the spring (13) force and the pressurized oil is supplied to the brake circuit preferentially. 8. This operation continues until the pressurized oil is accumulated in service brake accumulators (17, 18) and the accumulator pressure reaches the cutout pressure.

abc-

To Brake Valve (Front) To Brake Valve (Rear) To Manifold Valve

1234567891011-

Orifice Orifice Spool Spring Passage Piston Pilot Piston Spring Check Valve Orifice Oil Chamber

121314151617-

T3-7-2

To Parking Brake

Priority Valve Spring Passage Orifice Spring Service Brake Accumulator (Front) 18- Service Brake Accumulator (Rear) 19- Pressure Sensor (Brake Primary Pressure)

SECTION 3 COMPONENT OPERATION Group 7 Brake Charge Valve / Manifold Valve Section A-A

c 8

14 13

d P

11 T

7 B

9 15 e

f Section B-B

9 g A

Section C-C

TNED-03-07-017

3 PT-

Port P (From Pilot Pump) Port T (To Hydraulic Tank)

abc-

To Brake Valve (Port PA) To Brake Valve (Port PB) To Manifold Valve

de-

To Parking Brake To Service Brake Accumulator (Front)

To Service Brake Accumulator (Rear)

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

13141516-

Spring Passage Orifice Spring

T3-7-3

SECTION 3 COMPONENT OPERATION Group 7 Brake Charge Valve / Manifold Valve  After pressure accumulation finish 1. The pressurized oil in passage (5) is routed to piston (6). 17

2. In addition, the pressure of service brake accumulators (17, 18) is blocked by check valve (9) and is kept.

3. When the pressure accumulated in service brake accumulators (17, 18) reaches the cutout pressure, piston (6) and pilot piston (7) are moved up (down on the circuit diagram) by the passage (5) force.

4 5 6 7

d 19

4. Passage (14) is connected to port T (hydraulic 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 (12) is moved to the left.

8 9 10

6. Consequently, more pressurized oil in port P flows to the brake circuit and manifold valve.

7. This operation continues until the service brake is applied (the brake circuit pressure decreases).

11 TNED-03-07-015

abc-

To Brake Valve (Front) To Brake Valve (Rear) To Manifold Valve

1234567891011-

Orifice Orifice Spool Spring Passage Piston Pilot Piston Spring Check Valve Orifice Oil Chamber

121314151617-

T3-7-4

To Parking Brake

Priority Valve Spring Passage Orifice Spring Service Brake Accumulator (Front) 18- Service Brake Accumulator (Rear) 19- Pressure Sensor (Brake Primary Pressure)

SECTION 3 COMPONENT OPERATION Group 7 Brake Charge Valve / Manifold Valve Section A-A

c 8

14 13

d P

11 T

7 B

9 15 e

f Section B-B

9 g A

Section C-C

TNED-03-07-017

3 PT-

Port P (From Pilot Pump) Port T (To Hydraulic Tank)

abc-

To Brake Valve (Port PA) To Brake Valve (Port PB) To Manifold Valve

de-

To Parking Brake To Service Brake Accumulator (Front)

To Service Brake Accumulator (Rear)

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

13141516-

Spring Passage Orifice Spring

T3-7-5

SECTION 3 COMPONENT OPERATION Group 7 Brake Charge Valve / Manifold Valve (Blank)

T3-7-6

SECTION 3 COMPONENT OPERATION Group 7 Brake Charge Valve / Manifold Valve Manifold Valve a

The manifold valve consists of pilot relief valve (1), torque control solenoid valve (2), control lever lock solenoid valve (3), and pilot accumulator (front) (4).

DR3

DR4

P2 PS2

DR5 DR2 PP1

4 d TNDB-03-04-001

DR3 DR4

1 P2 PS2

DR2

PP1

DR5 S1

TNDB-03-07-007

From Brake Charge Valve (Unloader Valve) (Pilot

12-

Pilot Relief Valve Torque Control Solenoid Valve

Pressurized Oil)

To Pump Regulator, Ride Control Valve

de-

To Pilot Valve To Pump Regulator

Front Control Lever Lock Solenoid Valve

Pilot Accumulator (Front)

Pressure Sensor (Primary Pilot Pressure)

T3-7-7

SECTION 3 COMPONENT OPERATION Group 7 Brake Charge Valve / Manifold Valve Pilot Relief Valve Pilot relief valve (1) keeps the pilot pump pressure supplied to port P to the specified pressure. Operation 1. Pressurized oil from port P is routed to the spool (3) end through spool (3). 2. When the pressure at port P is larger than the spring (2) force, spool (3) compresses spring (2) and moves up. 3. Pressurized oil from port P flows to port DR4 (hydraulic tank) and the pressure at port P decreases. 4. When the pressure at port P decreases, spool (3) is moved down by the spring (2) force. 5. Therefore, port P is disconnected to port DR4 by spool (3). 6. The pressure at port P is controlled to keep constant by repeating the above operations.

1 Section A-A

2 A

A DR4

3 P

TNDB-03-07-008 1-

Pilot Relief Valve

Spring

T3-7-8

Spool

TNDB-03-07-018

SECTION 3 COMPONENT OPERATION Group 7 Brake Charge Valve / Manifold Valve Torque Control Solenoid Valve Torque control solenoid valve (2) supplies torque control pressure ST according to the signal from MC to the pump regulator. (Refer to SYSTEM/Hydraulic System.) Torque control solenoid valve (2) is a proportional solenoid valve.

Section A-A

e X1

A DR3

TNED-03-07-019

TNDB-03-07-008

To Pump Regulator

Torque Control Solenoid Valve

T3-7-9

SECTION 3 COMPONENT OPERATION Group 7 Brake Charge Valve / Manifold Valve Proportional Solenoid Valve The proportional solenoid valve is controlled by the electric current signal from MC (main controller) and outputs the pressure in proportion to the electric current.  When in neutral 1. Spring (2) pushes spool (1) to the right and output port X1 is connected to tank port DR3.

 When excited 1. Solenoid (3) pushes spool (1) to the left in proportion to the current value flowing through solenoid (3). 2. The pilot pressurized oil from port P2 flows to output port X1 and the pressure at output port X1 increases. 3. This pressure at output port X1 is routed to stepped part (a) of spool (1). Spool (1) is pushed to the right due to the difference in the pressure receiving area between stepped part (a). 4. When the pressure at output port X1 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 X1 and port P2 is closed. Therefore, the pressure at output port X1 stops increasing.

DR3

a TDAA-03-07-013

Spool

Spring

T3-7-10

Solenoid

SECTION 3 COMPONENT OPERATION Group 7 Brake Charge Valve / Manifold Valve Control Lever Lock Solenoid Valve Control lever lock solenoid valve (3) is shifted by the control lever lock switch and supplies the pilot pressurized oil to the pilot valve. Control lever lock solenoid valve (3) is an ON/OFF solenoid valve.

Section B-B When unexcited (The control lever lock switch is in the OFF position.)

DR2 P2

PP1

4 B

5 d

TNED-03-07-020

B When excited (The control lever lock switch is in the ON position.)

DR2

3 P2 TNED-03-07-008

PP1

4 d-

To Pilot Valve

Control Lever Lock Solenoid Valve

45-

Solenoid Spool

T3-7-11

Spring

5 d

TNED-03-07-020

SECTION 3 COMPONENT OPERATION Group 7 Brake Charge Valve / Manifold Valve Service Brake Accumulator The service brake accumulator is installed in the accumulation circuit of the brake charge valve. The high-pressure nitrogen gas is contained in the accumulator and the pressurized oil from the pilot pump compresses the nitrogen gas through the piston. The service brake circuit pressure oil is retained by the compression of the nitrogen gas. Service Brake Accumulator Specifications N2 gas capacity N2 gas charging pressure

L (quart)

1.4 (1.5)

MPa (PSI)

6.8 (986)

TNED-03-07-021

T3-7-12

SECTION 3 COMPONENT OPERATION Group 7 Brake Charge Valve / Manifold Valve Pilot Accumulator The pilot accumulator is installed in the manifold valve. High-pressure nitrogen gas (1) is contained in the accumulator and the pressurized oil from the pilot pump compresses nitrogen gas (1) through bladder (2). The pilot each circuit pressure oil is retained by the compression of nitrogen gas (1). Pilot Accumulator Specifications N2 gas capacity N2 gas charging pressure

L (quart)

0.5 (0.5)

MPa (PSI)

1.57 (228)

T1F3-03-08-007

Pressurized Oil from Pilot Pump

Nitrogen Gas

Bladder

T3-7-13

SECTION 3 COMPONENT OPERATION Group 7 Brake Charge Valve / Manifold Valve (Blank)

T3-7-14

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Outline The drive unit consists of transmission (2) and torque converter (1). The drive unit is connected with the engine. The output power from the engine is transmitted to transmission (2) through the engine flywheel and torque converter (1).

b a

TNDB-03-09-002

2 a-

Engine Side

Main Pump Side

Torque Converter

Transmission

T3-8-1

Propeller Shaft Side

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Side View of Transmission

5 6

8 9

11 12

1234-

Torque Converter Torque Converter Housing Torque Converter Input Speed Sensor Breather

567-

Transmission Intermediate Shaft Sensor Torque Converter Output Speed Sensor Transmission Case Cover

TNDB-03-09-002

891011-

T3-8-2

Adapter for Remote Filter Filter Parking Brake Front Axle Output Flange

12- Drain Plug with Magnet (M38×1.5) 13- Rear Axle Output Flange 14- Transmission Case

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Transmission Pressure Test Port

View B 1

View A

View Y 11

TNDB-03-09-009

12345-

System Main Pressure Test Port Torque Converter Input Pressure Test Port Reduced Oil Pressure Test Port Harness Connector High-Speed Forward Clutch Pressure Test Port

678-

Reverse Clutch Pressure Test Port First Speed Clutch Pressure Test Port Third Speed Clutch Pressure Test Port

Low-Speed Forward Clutch Pressure Test Port 10- Second Speed Clutch Pressure Test Port 11- Transmission Oil Cooler Returning Oil Pressure Test Port

T3-8-3

12- Transmission Oil Cooler Output Oil Pressure Test Port 13- Torque Converter Outlet Temperature Test Port

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Front View of Transmission

3 6

TNDB-03-09-003

12-

Main Pump Drive Shaft Transmission Control Valve

34-

Parking Brake Transmission Mount Base

56-

T3-8-4

Front Axle Output Flange Filter

Adapter for Remote Filter

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Cross Section of Transmission (Section A-A)

10 9 T4GB-03-09-004

123-

First Speed Clutch High-Speed Forward Clutch Reverse Clutch

456-

Hydraulic Pump Drive Low-Speed Forward Clutch Second Speed Clutch

789-

T3-8-5

Third Speed Clutch Front Output Flange Output Shaft

10- Rear Output Flange 11- Torque Converter

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Torque Converter

fNOTE: Torque converter housing is so designed as to

A single-stage torque converter is adopted. The torque converter consists of impeller (3), turbine (1), and stator (2).

be dry inside. Normally, oil leakage does not occur in this area. Torque converter does not contain serviceable parts. So, in the case of a failure, replace the whole device.

Operation

fNOTE: High-speed drive gear (8) and low-speed drive

1. Impeller (3) drives the oil in the torque converter. Notch ring (11) is welded to impeller (3). This works as the pick-up point of the torque converter input speed sensor.

gear (9) are integral with torque converter input shaft (13).

2. Drive tube (12) is also welded to impeller (3). Drive tube (12) drives the inner gear of transmission pump (5). 3. Impeller shaft (7) is connected to torque converter input shaft (13) with spline joint, and drives the main pump. 4. As impeller (3) rotates, it forcefully flows oil, against turbine (1). 5. Turbine (1) and impeller (3) rotate in the same direction. Turbine (1) is connected to turbine shaft (10) with spline joint. Turbine shaft (10) rotates drive gears (8, 9) for transmitting torque to the clutch. 6. Oil, coming out of turbine (1), flows in the opposite direction of impeller (3). 7. This oil enters stator (2). 8. As the blade inside stator (2) is bent, oil flows in the same direction as impeller (3). 9. Turbine (1) rotates more slowly than impeller (3). 10. Therefore, the torque converter functions as a torque amplifier. 11. Maximum output torque is generated when impeller (3) is rotating at the maximum speed with turbine (1) stopped.

T3-8-6

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit

13 T4GB-03-09-001

Engine Side

Main Pump Side

1234-

Turbine Stator Impeller Oil Seal

5678-

Transmission Pump Seal Ring Impeller Shaft High-Speed Drive Gear

9101112-

T3-8-7

Low-Speed Drive Gear Turbine Shaft Notch Ring Drive Tube

13- Torque Converter Input Shaft

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Transmission High-speed forward clutch (2) is provided with two output gears (2-c, 2-d). High-speed forward clutch (2) is operated when it is connected. Two output gears (2-c, 2-d) of high-speed forward clutch (2) are operated when it is disconnected. Main pressurized oil flows through the passage in the shaft of each clutch, and connects the clutches. Lubrication oil is distributed to the respective clutch shafts through the manifold plate installed between the torque converter and the transmission case.

Transmission is the hydraulic power shift type. There are six clutches, and five forward speed shifts and three reverse speed shifts are available depending on the combination of the respective packs. Two clutches need to be connected for moving the machine body. One of them is for determining the direction, and consists of lowspeed forward clutch (5), high-speed forward clutch (2), and reverse clutch (3). The other clutch is for determining the speed, and consists of first speed clutch (1), second speed clutch (6), and third speed clutch (7). Input (a) shaft is provided with two gears, and they transmits torque to drive gears (5-b, 3-b, and 2-b) of low-speed forward clutch (5), reverse clutch (3), and high-speed Forward clutch (5). The output gears (3-c, 2-c, and 6-c) of reverse clutch (3), high-speed forward clutch (2), and second speed clutch (6) are always geared, and transmit torque to first speed clutch drive gear (1-b) and third speed output gear (7-c). Transmission Gear Pattern (Viewed from Control Valve Side)

3-c

3-b

5-c 5-b

6-c

2-c

6-b

2-b

2-d

1-b

1-c

7-b

7-c

T106954 a-

Input (From Torque Converter)

Drive Gear

Output Gear

12-

First Speed Clutch High-Speed Forward Clutch

35-

Reverse Clutch Low-Speed Forward Clutch

67-

Second Speed Clutch Third Speed Clutch

Output Shaft

T3-8-8

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Transmission Clutch Engagement as per Selected Speed Shift  Transmission Clutch Engagement Directional Control Clutch Selected Speed Low-Speed High-Speed Shift Forward Forward Forward Speed  1 (F1) Forward Speed  2 (F2)  Forward Speed 3 (F3) Forward Speed  4 (F4)  Forward Speed 5 (F5) Reverse Speed 1 (R1) Reverse Speed 2 (R2) Reverse Speed 3 (R3)

Reverse

Speed Control Clutch First Speed Second Speed

Third Speed

     



T3-8-9

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Operation of Transmission Forward Speed 1 1. In case of forward speed 1, low-speed forward clutch (5) and first speed clutch (1) are connected. 2. Torque (a) inputted by the torque converter enters drive gear (5-b) of low-speed forward clutch (5), and is transmitted to output gear (5-c).

3. Torque from output gear (5-c) of low-speed forward clutch (5) is transmitted to drive gear (1-b) of first speed clutch (1) through output gear (6-c) of second speed clutch (6), output gear (2-c, 2-d) of high-speed forward clutch (2), and output gear (1-c) of first speed clutch (1). 4. Then, the torque is outputted to output gear (7-c) of third speed clutch (7) through drive gear (1-b) of first speed clutch (1), and finally to output shaft gear (9).

5-c 5-b

2 6-c 2-c

6 2-d

1-c

1-b 7-c

T106956

T3-8-10

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit

1-b 1-c

2 2-d

2-c

a 5-b

5 5-c

6-c

6 7-c

T4GB-03-09-005 a-

Input (From Torque Converter)

Drive Gear

Output Gear

12-

First Speed Clutch High-Speed Forward Clutch

56-

Low-Speed Forward Clutch Second Speed Clutch

79-

Third Speed Clutch Output Shaft Gear

11- Torque Converter

T3-8-11

Output Gear

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Forward Speed 2 1. In case of forward speed 2, low-speed forward clutch (5) and second speed clutch (6) are connected.

3. Torque from output gear (5-c) of low-speed forward clutch (5) is transmitted to drive gear (6-b) through output gear (6-c) of second speed clutch (6).

2. Torque (a) inputted by the torque converter enters drive gear (5-b) of low-speed forward clutch (5), and is transmitted to output gear (5-c).

4. Torque is transmitted to output shaft gear (9) through drive gear (6-b) of second speed clutch (6) and output gear (7-c) of third speed clutch (7).

5-c 5-b 6-c

6-b

6 1

TNEE-03-08-001

T3-8-12

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit

5-b

5-c

6-c

6 7-c

TNEE-03-08-002 a-

Input (From Torque Converter)

Drive Gear

56-

Low-Speed Forward Clutch Second Speed Clutch

79-

Third Speed Clutch Output Shaft Gear

11- Torque Converter

T3-8-13

Output Gear

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Forward Speed 3 1. In case of forward speed 3, high-speed forward clutch (2) and second speed clutch (6) are connected. 2. Torque (a) inputted from the torque converter is transmitted to output gear (6-c) of second speed clutch (6) through drive gear (2-b) of high-speed forward clutch (2) and output gear (2-c). 3. Torque is transmitted to drive gear (6-b) through output gear (6-c) of second speed clutch (6). 4. Torque from drive gear (6-b) of second speed clutch (6) is transmitted to output shaft gear (9) through output gear (7-c) of third speed clutch (7).

6-c

6-b

2-c 2-b

7-c

TNEE-03-08-003

T3-8-14

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit

2-c

2-b

6-c 6-b

6 7

7-c

TNEE-03-08-004 a-

Input (From Torque Converter)

Drive Gear

26-

High-Speed Forward Clutch Second Speed Clutch

79-

Third Speed Clutch Output Shaft Gear

11- Torque Converter

T3-8-15

Output Gear

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Forward Speed 4 1. In case of forward speed 4, low-speed forward clutch (5) and third speed clutch (7) are connected. 2. Torque (a) inputted by the torque converter enters drive gear (5-b) of low-speed forward clutch (5), and is transmitted to output gear (5-c).

3. Torque from output gear (5-c) of low-speed forward clutch (5) is transmitted to drive gear (7-b) of third speed clutch (7) through output gear (6-c) of second speed clutch (6). 4. Torque is transmitted to output shaft gear (9) through drive gear (7-b) of third speed clutch (7) and output gear (7-c).

5-c 5-b

6-c

6 1

7-c 7-b

TNEE-03-08-005

T3-8-16

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit

5-b

5-c 6-c

6 7-b 7-c

7 9

TNEE-03-08-006 a-

Input (From Torque Converter)

Drive Gear

56-

Low-Speed Forward Clutch Second Speed Clutch

79-

Third Speed Clutch Output Shaft Gear

11- Torque Converter

T3-8-17

Output Gear

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Forward Speed 5 1. In case of forward speed 5, high-speed forward clutch (2) and third speed clutch (7) are connected. 2. Torque (a) inputted from the torque converter is transmitted to output gear (6-c) of second speed clutch (6) through drive gear (2-b) of high-speed forward clutch (2) and output gear (2-c). 3. Torque is transmitted to output shaft gear (9) through output gear (6-c) of second speed clutch (6), drive gear (7-b) of third speed clutch (7), and output gear (7-c).

6-c

2-c 2-b

7-b

9 7-c

T106958

T3-8-18

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit

2-c

2-b

6-c

6 7

7-b

7-c

T4GB-03-09-006 a-

Input (From Torque Converter)

Drive Gear

26-

High-Speed Forward Clutch Second Speed Clutch

79-

Third Speed Clutch Output Shaft Gear

11- Torque Converter

T3-8-19

Output Gear

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Reverse Speed 1 1. In case of reverse speed 1, reverse clutch (3) and first speed clutch (1) are connected. 2. Torque (a) inputted from the torque converter is transmitted to output gear (b) of first speed clutch (1) through drive gear (3-b) of reverse clutch (3), output gear (3-c), output gear (2-c, 2-d) of highspeed forward clutch (2). 3. Torque is transmitted to output shaft gear (9) through output gear (1-c) of first speed clutch (1), drive gear (1-b), and output gear (7-c) of third speed clutch (7).

3 3-b

3-c

2 2-c 2-d

1 7-c 1-b

1-c

T106957

T3-8-20

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit

1-b 1-c

2-d

2-c

3-c

3-b

7-c

T4GB-03-09-007 a-

Input (From Torque Converter)

Drive Gear

12-

First Speed Clutch High-Speed Forward Clutch

37-

Reverse Clutch Third Speed Clutch

9- Output Shaft Gear 11- Torque Converter

T3-8-21

Output Gear

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Reverse Speed 2 1. In case of reverse speed 2, reverse clutch (3) and second speed clutch (6) are connected. 2. Torque (a) inputted from the torque converter is transmitted to drive gear (6-b) of second speed clutch (6) through drive gear (3-b) of reverse clutch (3), output gear (3-c), output gear (2-c) of highspeed forward clutch (2), and output gear (6-c) of second speed clutch (6). 3. Torque from drive gear (6-b) of second speed clutch (6) is transmitted to output shaft gear (9) through output gear (7-c) of third speed clutch (7).

3 3-c

3-b

6 2 6-c 2-c

6-b

7-c

TNEE-03-08-007

T3-8-22

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit

2-c 3-c

11 3-b a

6-c 6-b

6 7-c

TNEE-03-08-008 a-

Input (From Torque Converter)

Drive Gear

23-

High-Speed Forward Clutch Reverse Clutch

67-

Second Speed Clutch Third Speed Clutch

9- Output Shaft Gear 11- Torque Converter

T3-8-23

Output Gear

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Reverse Speed 3 1. In case of reverse speed 3, reverse clutch (3) and third speed clutch (7) are connected. 2. Torque (a) inputted from the torque converter is transmitted to drive gear (7-b) of third speed clutch (7) through drive gear (3-b) of reverse clutch (3), output gear (3-c), output gear (2-c) of high-speed forward clutch (2), and output gear (6-c) of second speed clutch (6). 3. Torque is transmitted to output shaft gear (9) through drive gear (7-b) of third speed clutch (7) and output gear (7-c).

3 3-c

3-b

6-c

2-c

7 7-c

9 7-b

TNEE-03-08-009

T3-8-24

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit

2-c 3-c

11 3-b a

6-c

6 7-b 7-c

TNEE-03-08-010 a-

Input (From Torque Converter)

Drive Gear

23-

High-Speed Forward Clutch Reverse Clutch

67-

Second Speed Clutch Third Speed Clutch

9- Output Shaft Gear 11- Torque Converter

T3-8-25

Output Gear

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Transmission Control Valve Pressure control valve (2) is a spring type spool valve, and controls system main pressurized oil (a) by adjusting the flow rate entering the control circuit. Oil not used for the control circuit flows to the torque converter.

Damper valve (9) operates as an accumulator of the control circuit. Peak pressure is absorbed by damper valve (9) and smoothens the spool (10) movement. Damper valves (9) are all the same ones.

System main pressurized oil (a) flows to pressure reducing valve (3) of electromagnetic type. This pressure reducing valve (3) supplies pressurized oil of the specified pressure to proportional solenoid valves (13), and the pressure remains unchanged even if the shift is changed. However, pressure adjustment of pressure reducing valve (3) is not possible.

When the machine moves, two clutches are connected. The low-speed forward clutch, high-speed forward clutch, and reverse clutch are directional controls, and first speed clutch, second speed clutch, and third speed clutch are speed control clutches.

Six proportional solenoid valves (13) lead oil to the respective clutches, and select or shift speed shift and forward/reverse travel direction. TCU sends variable electric signals to proportional solenoid valves (13) for smooth connection of the clutch. Six proportional solenoid valves (13) and spools (10) are all the same ones.  Proportional solenoid valve Y1 moves the highspeed forward clutch.  Proportional solenoid valve Y2 moves the reverse clutch.  Proportional solenoid valve Y3 moves the first speed clutch.  Proportional solenoid valve Y4 moves the third speed clutch.  Proportional solenoid valve Y5 moves the low-speed forward clutch.  Proportional solenoid valve Y6 moves the second speed clutch.  Transmission Clutch Engagement and Proportional Solenoids (Y1 to Y5) Activated Directional Control Clutch Selected Speed Shift Low-Speed High-Speed Forward Forward Forward Speed 1 (F1) Solenoid Y5 Forward Speed 2 (F2) Solenoid Y5 Forward Speed 3 (F3) Solenoid Y1 Forward Speed 4 (F4) Solenoid Y5 Forward Speed 5 (F5) Solenoid Y1 Reverse Speed 1 (R1) Reverse Speed 2 (R2) Reverse Speed 3 (R3)

Reverse

Speed Control Clutch First Speed Second Speed Third Speed Solenoid Y3 Solenoid Y6 Solenoid Y6 Solenoid Y4 Solenoid Y4

Solenoid Y2 Solenoid Y2 Solenoid Y2

T3-8-26

Solenoid Y3 Solenoid Y6 Solenoid Y4

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit 1

5 6 7 a

T107151

3 2

T107153

ab-

System Main Pressurized Oil Returning Oil

Reduced Pressurized Oil

Converter Pressurized Oil (Return Oil)

1234-

Valve Body Pressure Control Valve Pressure Reducing Valve Connector

5678-

Middle Plate Channel Plate Plate Cover

9101112-

Damper Valve Spool Housing Modulation Circuit

T3-8-27

13- Proportional Solenoid Valve

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Drive Unit Circuit

2 1

17 9 19

18 10

16 11 22

15 12

14 13

T4GB-03-09-010

12345678-

Damper Valve High-Speed Forward Clutch Booster Valve Reverse Clutch First Speed Clutch Third Speed Clutch Low-Speed Forward Clutch Second Speed Clutch

91011121314-

Pressure Reducing Valve Oil Filter Oil Filter Bypass Valve Oil Filter Restriction Switch Charging Pump Torque Converter Oil Cooler (Installed on Rear of Machine)

15- Torque Converter Oil Cooler (Installed on Drive Unit) 16- Torque Converter Back Pressure Valve 17- Main Relief Valve 18- Torque Converter Relief Valve 19- Torque Converter

T3-8-28

20- Transmission Oil Temperature Sensor 21- Proportional Solenoid Valve 22- Torque Converter Cooler Check Valve

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Parking Brake Manual Release Once the parking brake is released, dWARNING: stopping the machine becomes impossible with the brake system. Before releasing the parking brake be sure to chock tires with wheel stoppers. If the parking brake cannot be released due to an engine or electrical problem, such as a failed parking brake solenoid valve coil or electrical circuit, perform the following operation.

1. Rotate cap (1) counterclockwise and remove cap (1). 7

2. Rotate lock nut (2) counterclockwise by using tool (3) and remove lock nut (2).

MNEC-06-003

j : 24 mm 4

MNEC-06-004

3. Rotate set bolt (4) counterclockwise by using hexagon wrench (5) until brake disk (7) becomes completely free.

l : 8 mm m : 70 N·m (51.6 lbf·ft) 4. Install and tighten lock nut (2) until it contacts to piston (6). 5. Install cap (1) and lightly tighten it to prevent dust from adhering to the lock nut.

5 MNEC-06-005

fNOTE: Refer to T3-11 for the parking brake solenoid valve and accumulator.

T3-8-29

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit (Blank)

T3-8-30

SECTION 3 COMPONENT OPERATION Group 9 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).

T4GB-03-10-001

Axle Shaft

Final Drive

T3-9-1

Differential

Brake

SECTION 3 COMPONENT OPERATION Group 9 Axle Differential The differential enables the left and right drive wheels to rotate at different speeds while steering and traveling on uneven surfaces.

3 2 1

13 14 15 16 17 18 19 20 21 T4GB-03-10-002

123456-

Brake Ring Brake Disc Piston Side Gear Case A Ring Gear

789101112-

Pinion Gear Spider Case B Roller Bearing Differential Body Gear & Shaft

131415161718-

T3-9-2

Adjusting Nut Bearing Retainer Pinion Shaft Roller Bearing Bearing Cage Spacer

19- Roller Bearing 20- Oil Seal 21- Flange

SECTION 3 COMPONENT OPERATION Group 9 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.

b c T202-03-05-005 a-

Extension Line of Rear Wheel Centers

While Turning the Machine

T3-9-3

Traveling on Rough Surfaces

SECTION 3 COMPONENT OPERATION Group 9 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-

T3-9-4

Rack A Pinion

Rack B

SECTION 3 COMPONENT OPERATION Group 9 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).

3 T202-03-05-007

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. 8

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 machine 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.

9 4

2 6

T202-03-05-008

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.

T3-9-5

SECTION 3 COMPONENT OPERATION Group 9 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

12-

Left Side Gear Differential Pinion Gear

Right Side Gear

T3-9-6

T487-03-06-015

SECTION 3 COMPONENT OPERATION Group 9 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.

T3-9-7

T487-03-06-017

SECTION 3 COMPONENT OPERATION Group 9 Axle Limited Slip Differential (LSD) (Option) 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.

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.

1 2 3

4 5 6 8

T4GB-03-10-003

12-

Ring Gear Pressure Ring

34-

Side Gear Pressure Plates

56-

T3-9-8

Clutch Discs Case

78-

Pinion Gear Spider

SECTION 3 COMPONENT OPERATION Group 9 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)

1. Drive force is transmitted to the case, pressure ring (2), and spider (8) through the ring gear.

2. At this time, spider (8) having the cam construction pushes pressure ring (2) toward the case with thrust P. 8

3. Clutch disc (5) is geared with the case through pressure ring (2).

Thrust "P"

4. Side gears connected to clutch disc (5) by spline joint rotate solidly with the case, and the left and right side gears rotate at the same speed. 5. Therefore, the left and right axle shafts connected to the side gears by spline joint tend to rotate solidly, together with the case, and the differential movement restriction works, resulting in better overall traction and less tire slippage.

T4GB-03-10-004

24-

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 the clutch disc begins to slip), the left and right gears 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.

T3-9-9

Pressure Ring Pressure Plates

58-

Clutch Discs Spider

SECTION 3 COMPONENT OPERATION Group 9 Axle Service Brake The type of service brake used is a wet-type multi-disc brake and is assembled in the differential housing 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 (5) and moves brake piston (5), so that brake friction disc (3) and brake plate (2) are compressed. 2. The inner surface of brake disc (3) is splined to shaft (8) through disk hub (7). 3. In addition, the outer surface of brake plate (2) is fixed to differential housing (4). 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 (5) is returned by return spring (6). 2. Brake friction disc (3) is released and machine brakes are released.

T3-9-10

SECTION 3 COMPONENT OPERATION Group 9 Axle 1

4 5

6 7

8 T4GB-03-10-005

When brake is applied 1

When brake is released 2

T4GB-03-10-007

T4GB-03-10-008

Brake Pressurized Oil

From Brake Valve

To Brake Valve

12-

End Plate Brake Plates

34-

Brake Discs Differential Body

56-

Brake Piston Return Spring

T3-9-11

78-

Disc Hub Shaft

SECTION 3 COMPONENT OPERATION Group 9 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 from shaft (7) and rotates three planetary gears (4) at ring gear (3). The rotation of planetary gear (4) is transmitted to axle shaft (1) through planetary carrier (5).

Tire

5 4

12-

Axle Shaft Final Drive

34-

Ring Gear Planetary Gear

56-

T3-9-12

Planetary Carrier Housing

Shaft

T4GB-03-10-006

SECTION 3 COMPONENT OPERATION Group 10 Brake Valve Outline Brake valve (2) supplies brake pressure in proportion to brake pedal (1) position. The oil is supplied to the front and rear axle service brakes. (Refer to SYSTEM / Hydraulic System.)

TNDB-03-10-001

2 1-

Brake Pedal

Brake Valve

T3-10-1

SECTION 3 COMPONENT OPERATION Group 10 Brake Valve Brake Valve Component Layout

12 11 10

TNED-03-09-006

8 PB

TNED-03-09-004

AB-

To Front Axle To Rear Axle

T- To Hydraulic Tank PA- From Charging Block (Port A)

PB- From Charging Block (Port B)

1234-

Push Rod Piston Retainer Control Spring 1

5678-

9101112-

Rod Control Spring 2 Spool Spool Return Spring

T3-10-2

Balance Spring Spool Holder Piston Return Spring

SECTION 3 COMPONENT OPERATION Group 10 Brake Valve (Blank)

T3-10-3

SECTION 3 COMPONENT OPERATION Group 10 Brake Valve Operation Neutral (Output Curve: A to B) 1. When the brake pedal is not applied, spools (10, 7) are pushed left by balance spring (9) and spool return spring (8) respectively.

a D

2. Spool (10) pushes control spring 2 (6) via rod (5) and holder (11). C

3. Piston (2) is pushed left by control spring 2 (6) and control spring 1 (4) via retainer (3). 4. Consequently, when the brake pedal is in the neutral position, pressurized oil from port PA and port PB are blocked by spools (10, 7) respectively. Port A and port B are connected to port T (hydraulic tank) through the outer circumference of spools (10, 7).

5. When the brake pedal is applied slightly, piston (2) moves right and pushes control spring 2 (6) via retainer (3). 6. As pressure at port A and port B are equal to that at port T and push spools (10, 7) to the left. When the force applied to spools (7, 10) becomes larger than the spring force of spool return spring (8), spools (7, 10) move to the right, block the oil flows between port T and ports (A, B). 7. This status continues until notches C on spools (10, 7) are connected to port A and port B respectively.

T3-10-4

Pressure in Ports A, B

Piston Stroke

TNED-03-09-003

SECTION 3 COMPONENT OPERATION Group 10 Brake Valve

7 A

B T

12 11 10

AB-

To Front Axle To Rear Axle

T- To Hydraulic Tank PA- From Charging Block (Port A)

PB- From Charging Block (Port B)

123-

Push Rod Piston Retainer

456-

789-

Control Spring 1 Rod Control Spring 2

T3-10-5

Spool Spool Return Spring Balance Spring

TNED-03-09-006

10- Spool 11- Holder 12- Piston Return Spring

SECTION 3 COMPONENT OPERATION Group 10 Brake Valve During Metering or Decompressing (Output Curve: B to C) 1. When the brake pedal is applied further and piston (2) is pushed, notches C on spools (10, 7) are connected to port PA and port PB respectively and pressurized oil is sent to the brake circuit by connecting port A and port B.

a D

2. Pressurized oil in port A and port B act on the chambers of balance spring (9) and spool return spring (8) through each spool hole D as spool reactive force.

3. Control spring 2 (6) force balances with the resultant force [pressure in port A and port B + spool return spring (8) force] and balance spring (9) force. Also reacting chamber pressure in proportion to control spring 2 (6) force is generated.

4. Pressurized oil in spool return spring (8) chamber and balance spring (9) chamber act as reactive force to return the spool. The oil flows between ports PA and A and between ports PB and B are blocked, and the pressure in port A and port B is maintained. The result is that the brake pressure to the service brakes is regulated, proportionate to the position of the brake pedal that is acting on the brake valve.

T3-10-6

Pressure in Ports A, B

Piston Stroke

TNED-03-09-003

SECTION 3 COMPONENT OPERATION Group 10 Brake Valve

7 A D

B D

12 11 10

TNED-03-09-006

7 A D

TNED-03-09-009

TNED-03-09-010

AB-

To Front Axle To Rear Axle

T- To Hydraulic Tank PA- From Charging Block (Port A)

PB- From Charging Block (Port B)

123-

Push Rod Piston Retainer

456-

789-

Control Spring 1 Rod Control Spring 2

T3-10-7

Spool Spool Return Spring Balance Spring

10- Spool 11- Holder 12- Piston Return Spring

SECTION 3 COMPONENT OPERATION Group 10 Brake Valve Full Stroke (Output Curve: C to D) 1. When the brake pedal is fully stroked, piston (2) compresses springs (12, 6) via retainer (3). a

2. Springs (12, 6) push rod (5) inward via holder (11) and spools (10, 7) move right.

3. At this time, the force pushing spools (10, 7) left (pressure in port A and port B + spring (8) force) balances with the force pushing spools (10, 7) right (balance spring (6) force + spring (12) force). Reacting pressure in proportion to control spring 2 (6) force and piston return spring (12) force are generated in these spring chambers.

T3-10-8

Pressure in Ports A, B

Piston Stroke

TNED-03-09-003

SECTION 3 COMPONENT OPERATION Group 10 Brake Valve

7 A

B T

12 11 10

AB-

To Front Axle To Rear Axle

T- To Hydraulic Tank PA- From Charging Block (Port A)

PB- From Charging Block (Port B)

123-

Push Rod Piston Retainer

456-

789-

Control Spring 1 Rod Control Spring 2

T3-10-9

Spool Spool Return Spring Balance Spring

TNED-03-09-006

10- Spool 11- Holder 12- Piston Return Spring

SECTION 3 COMPONENT OPERATION Group 10 Brake Valve (Blank)

T3-10-10

SECTION 3 COMPONENT OPERATION Group 11 Ride Control Valve Outline Ride control valve (1) 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

T3-11-1

SECTION 3 COMPONENT OPERATION Group 11 Ride Control Valve Layout

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 Tank Charge-Cut Spool Ride Control Spool

9- Overload Relief Valve 10- Orifice 11- Drain Plug

Pi-

T3-11-2

Port B (to Lift Arm Cylinder Rod Side) Port Pi (Pilot Pressurized Oil)

PS2- Port PS2 (to Ride Control Accumulator) T- Port T (to Hydraulic Tank)

SECTION 3 COMPONENT OPERATION Group 11 Ride Control Valve

PS2

9 b

a A

Section a-a

TNDB-03-12-001

Section b-b

PS2

PS2 A T T TNDB-03-12-003

T3-11-3

T4GD-03-08-001

SECTION 3 COMPONENT OPERATION Group 11 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 pressurized 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 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.

T3-11-4

SECTION 3 COMPONENT OPERATION Group 11 Ride Control Valve

5 Pi

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 Pressurized Oil)

PS2- Port PS2 (to Ride Control Accumulator) T- Port T (to Hydraulic Tank)

456-

Ride Control Solenoid Valve Pilot Pump Ride Control Accumulator

78-

T3-11-5

Spring Hydraulic Tank

TNDB-03-12-006

SECTION 3 COMPONENT OPERATION Group 11 Ride Control Valve Charge-Cut Spool Charge-cut spool (3) makes the ride control accumulator accumulate pressurized oil up 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.

T3-11-6

SECTION 3 COMPONENT OPERATION Group 11 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

T3-11-7

T4GB-03-08-008

SECTION 3 COMPONENT OPERATION Group 11 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 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).

T3-11-8

SECTION 3 COMPONENT OPERATION Group 11 Ride Control Valve Normal Operation: 12

T176-03-03-012

Relief Operation: 1

HP- Actuator Circuit

LP- Hydraulic Tank

123-

456-

Main Poppet Orifice A Orifice B

Seat Passage A Spring B

8- Pilot Poppet 9- Spring A 10- Spring Chamber

T3-11-9

T176-03-03-013

11- Sleeve 12- Spring C 13- Make-Up Valve

SECTION 3 COMPONENT OPERATION Group 11 Ride Control Valve Make-Up Operation 1. When pressure in port HP (actuator circuit) decreases lower than pressure in port LP (hydraulic 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).

T3-11-10

SECTION 3 COMPONENT OPERATION Group 11 Ride Control Valve Make-Up Operation: 12

TNDB-03-12-013

HP- Actuator Circuit

LP- Hydraulic Tank

12- Spring C

13- Make-Up Valve

T3-11-11

SECTION 3 COMPONENT OPERATION Group 11 Ride Control Valve Drain Plug The ride control valve is provided with drain plug (2) in order to return pressurized oil of the ride control accumulator to hydraulic tank (4) at the time of maintenance or something. Pressurized oil from the ride control accumulator flows to hydraulic tank (4) by loosening drain plug (2). Therefore, the pressure of ride control accumulator decreases. CAUTION: Do not loosen drain plug (2) too much 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 Tank

T3-11-12

TNDB-03-12-010

SECTION 3 COMPONENT OPERATION Group 12 Others Propeller Shaft The propeller shafts are installed between the transmission and front axle, and between the transmission and rear axle, respectively. The propeller shafts transmit the power from the transmission to the front axle and rear axle. The adopted joint is universal joint (1) most commonly used.

Between Front Axle and Transmission 2

T4GB-03-12-003

Between Transmission and Rear Axle 1

2 1

2 2

T4GB-03-12-004

Universal Joint

Grease Fitting

T3-12-1

SECTION 3 COMPONENT OPERATION Group 12 Others (Blank)

T3-12-2

SECTION 3 COMPONENT OPERATION Group 12 Others Parking Brake Solenoid Valve Unit The parking brake solenoid valve unit is installed in the brake charge valve (unloader valve) and parking brake. The parking brake solenoid valve unit consists of the parking brake solenoid valve (2), block (1), and parking brake accumulator (3).

Pressure sensor (parking brake) (4) is a sensor which controls the parking brake indicator.

View A

6 a

TNEG-03-12-005

B TNEG-03-12-006

View B

TNEG-03-12-007

Front Side of Machine

123-

Block Parking Brake Solenoid Valve Parking Brake Accumulator

Pressure Sensor (Parking Brake)

T3-12-3

Port CV (Pilot Pressure PB from Brake Charge Valve (Unloader Valve))

67-

Port Dr (To Hydraulic Tank) Port SW (Parking Brake)

SECTION 3 COMPONENT OPERATION Group 12 Others Parking Brake Solenoid Valve The parking brake solenoid valve controls the parking brake according to the parking brake switch operation. (Refer to SYSTEM/Electrical System.) The parking brake solenoid valve is an ON/OFF solenoid valve. ON/OFF Solenoid Valve The ON/OFF solenoid valve is controlled by the electric current signal from the parking brake relay and shifts the pilot pressure.  When in neutral Spring (2) pushes pilot spool (1) to the right and output port A is connected to tank port T.  When operated 1. As solenoid (3) is activated, pilot spool (1) is pushed to the left. 2. Pilot port P is connected to output port A and tank port T is blocked.

T3-12-4

SECTION 3 COMPONENT OPERATION Group 12 Others  When in neutral (Parking brake switch: ON)

TNEJ-03-12-001

T A

 When operated (Parking brake switch: OFF) 2

TNEJ-03-12-002

T A

Pilot Spool

Spring

T3-12-5

Solenoid

SECTION 3 COMPONENT OPERATION Group 12 Others Parking Brake Accumulator The parking brake accumulator is installed in the parking brake solenoid valve unit. The high-pressure nitrogen gas (1) is contained in the accumulator, and the pressurized oil from the pilot pump compresses nitrogen gas (1) through bladder (2). Compression of nitrogen gas (1) keeps the parking brake release pressure. Parking Brake Accumulator Specifications N2 gas capacity

L (quart)

0.5 (0.5)

N2 gas charging pressure

MPa (PSI)

5.94 (861.5)

T1F3-03-08-007

Pressurized Oil from Pilot Pump

Nitrogen Gas

Bladder

T3-12-6

SECTION 3 COMPONENT OPERATION Group 12 Others Flow Regulator Valve

The flow regulator valve is installed in the circuit between the pilot valve and control valve. The flow regulator valve consists of shockless valves (1, 2) and restriction valve (3). Pressure sensors (S1) is sensor which monitor the pressure in the lift arm raise operation control circuits.

1 S1

TPD8-03-12-001

B3(3)

B A

TNEG-03-12-015

Front Left of Machine

Upper Side of Machine

A1- Lift Arm Raise (Control Valve Side) B1- Lift Arm Raise (Pilot Valve Side) S1- Pressure Sensor (Lift Arm Raise)

A2- Lift Arm Lower (Control Valve Side) B2- Lift Arm Lower (Pilot Valve Side) A3- Bucket Roll Back (Control Valve Side)

B3- Bucket Roll Back (Pilot Valve Side) A4- Bucket Dump (Control Valve Side) B4- Bucket Dump (Pilot Valve Side)

Shockless Valve (Lift Arm Raise Side)

Shockless Valve (Lift Arm Lower Side)

T3-12-7

Restriction Valve (Bucket Roll Back Side)

SECTION 3 COMPONENT OPERATION Group 12 Others Shockless Valve in Flow Regulator Valve The shockless valve in the flow regulator valve is installed in the circuit between the pilot valve and control valve (lift arm spool). The shockless valve prevents the quick movement of the return circuit in the lift arm spool. This valve reduces cavitation developed in the lift arm cylinder.

fNOTE: The illustration shows when stopping the lift

Section A-A

arm lower operation.

 Shockless Operation 1. Returning oil from the control valve flows to port A2 of the shockless valve.

3 5

2. Returning oil flows to chamber D (1) through orifice (6).

3. Returning oil in chamber D (1) flows to port B2 through passage (2) in spool (5) and housing (4), and the pressure in chamber D (1) decreases.

4. As the pressure difference between the upper and lower parts of orifice (6) occurs, spool (5) is moved down by the pressure acts on spring (3) side. Therefore, passage (2) in spool (5) and housing (4) is closed and returning oil is restricted. 5. When passage (2) is closed, the pressure in chamber D (1) increases and spool (5) is moved up. Then, passage (2) is opened again and returning oil flows to port B2. 6. As the operations in step 3 to step 5 are repeated and returning oil is gradually returned to port B1 side, the control valve spool is returned slowly.

TNEG-03-12-009

A2- Lift Arm Lower (Control Valve Side)

B2- Lift Arm Lower (Control Valve Side)

123-

456-

T3-12-8

Chamber D Passage Spring

Housing Spool Orifice

SECTION 3 COMPONENT OPERATION Group 12 Others Restriction Valve in Flow Regulator Valve The restriction valve in the flow regulator valve is installed in the circuit between the pilot valve and control valve (bucket spool). The slow return valve prevents the quick movement of the return circuit in the bucket spool. This valve reduces cavitation developed in the bucket cylinder.

Section B-B

 Restriction Operation 1. Returning oil from the control valve flows to port A3 of the restriction valve. 2. Returning oil flows to port B3 through orifice (8). 3. As the pressure difference between the right and left parts of orifice (8) occurs, returning oil is restricted.

4. As returning oil is gradually returned to port B3 side, the control valve spool is returned slowly. 7

8 TNEG-03-12-010

A3- Bucket Roll Back (Control Valve Side) B3- Bucket Roll Back (Pilot Valve Side)

S3- Pressure Sensor (Bucket Roll Back)

T3-12-9

Check Valve

Orifice

SECTION 3 COMPONENT OPERATION Group 12 Others Steering Accumulator The steering accumulator is installed in the circuit between the steering pilot valve and steering cylinder. The high-pressure nitrogen gas is contained in the accumulator and the pressurized oil compresses the nitrogen gas via the piston. Compression of the nitrogen gas dampens the shock of the pressurized oil when stopping steering.

Steering Accumulator Specifications N2 gas capacity

L (quart)

0.2 (0.2)

N2 gas charging pressure

MPa (PSI)

2.0 (290)

TNDF-03-14-002

Ride Control Accumulator (Option) The ride control accumulator is installed in the circuit between the control valve (ride control spool) and actuator. The high-pressure nitrogen gas is contained in the accumulator and the pressurized oil compresses the nitrogen gas via the piston. Compression of the nitrogen gas dampens the shock of the pressurized oil of the lift arm cylinder raise circuit. due to pitching of the vehicle body.

Ride Control Accumulator Specifications N2 gas capacity

L (quart)

2.5 (2.6)

N2 gas charging pressure

MPa (PSI)

3.0 (435)

TNEK-03-11-003

T3-12-10

SECTION 3 COMPONENT OPERATION Group 12 Others Torque Converter Cooler Check Valve The torque converter cooler check valve (1) is installed in the cooling circuit (between torque converter and torque converter oil) of the drive unit. When the cooling circuit of the torque converter oil becomes abnormal, the torque converter cooler check valve (1) is operated and the abnormal pressure is relieved.

Section A-A

1 TNEK-03-11-002

A 12-

Check Valve From Torque Converter Oil Cooler (OUT)

34-

To Torque Converter Cooler (IN) From Torque Converter (OUT)

To Torque Converter Oil Cooler (IN)

T3-12-11

SECTION 3 COMPONENT OPERATION Group 12 Others Pilot Oil Filter Pilot oil filter (1) is installed in the circuit between the pump device (pilot pump) and brake charge valve (unloader valve). When delivery pressure P from the pump becomes abnormally high, relief valve (2) is activated and protects filter (3).

MNEC-07-019

TNEG-03-12-014 P-

Pressurized Oil from Pilot Pump

12-

Pilot Filter Relief Valve

T3-12-12

Filter

SECTION 3 COMPONENT OPERATION Group 12 Others Secondary Steering Check Block (Option) P2

The secondary steering check block (1) is installed between the priority valve and the steering pilot valve. Built-in check valve (4) is provided for preventing from flowing delivery oil (PE) of the secondary steering pump to the priority valve.

Dr TNDB-03-11-005

Section A-A

S1 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 Tank

34-

Secondary Steering Check Block

Secondary Steering Pump Delivery Pressure Sensor

Steering Pressure Switch Check Valve

T3-12-13

P2- To Steering Pilot Valve

SECTION 3 COMPONENT OPERATION Group 12 Others Secondary Steering Pump (Option) The secondary steering pump is installed in the secondary steering circuit (between the steering pilot valve and hydraulic tank). The secondary steering pump is activated for a specified time and makes the steering operation possible when pressurized oil from the main pump becomes abnormal (steering pressure switch: ON).

The secondary steering pump consists of gear pump (2), electrical motor (3), and relief valve (1).

TNED-01-02-019

Relief Valve

Gear Pump

Electrical Motor

T3-12-14

INDEX A Accelerator Pedal Control...................................................... T2-2-8 Accessory Circuit ....................................................................T2-5-49 Accessory Circuit (Key Switch: ACC) .................................. T2-5-8 Accumulator, Parking Brake................................................T3-12-6 Accumulator, Pilot ..................................................................T3-7-13 Accumulator, Ride Control (Option) ............................. T3-12-10 Accumulator, Service Brake ................................................T3-7-12 Accumulator, Steering ....................................................... T3-12-10 After-Run Control ...................................................................T2-3-28 Aftertreatment Device.........................................T1-2-20, T2-3-36 Aftertreatment Device Manual Regeneration Control ..................................................................................T2-2-36 Aftertreatment Device Regeneration Control .............T2-3-38 Air Cleaner .................................................................................. T1-2-6 Air Conditioner Circuit ..........................................................T2-5-24 Alarm Control ..........................................................................T2-3-18 Alternator Operation.............................................................T2-5-14 Auto Idling Stop Circuit ........................................................T2-5-20 Auto Idling Stop Control ......................................................T2-2-88 Auto Power Up Speed Control...........................................T2-2-26 Auto-Warm Up Control ........................................................T2-2-10 Automatic Speed Shift Control..........................................T2-2-52 Axle, Outline ............................................................................... T3-9-1 Axle Shaft ..................................................................................T3-9-12 B Base Torque Control ..............................................................T2-2-40 Battery Box.................................................................................. T1-2-8 Brake Charge Valve (Unloader Valve) ............... T1-2-23, T3-7-2 Brake Charge Valve, Outline ................................................. T3-7-1 Brake Light Circuit ..................................................................T2-5-42 Brake Oil Low Pressure Indicator Control ......................T2-2-76 Brake Valve, Component Layout .......................................T3-10-2 Brake Valve, Operation .........................................................T3-10-4 Brake Valve, Outline ...............................................................T3-10-1 Bucket Auto Leveler Control...............................................T2-2-94 Bucket Dump Hydraulic Load Reduction ......................T2-2-42 C Cab ...............................................................................................T1-2-13 Cab Light Circuit .....................................................................T2-5-58 CAN Circuit....................................................................T2-1-2, T2-5-6 Charge-Cut Spool ...................................................................T3-11-6 Charging Circuit ........................................................................ T2-4-4 Charging Circuit (Key Switch: ON) ....................................T2-5-12 Combined Operation Circuit ..............................................T2-4-38 Component Layout.................................................................. T1-2-1 Component Specifications ................................................... T1-3-1 Control Lever Lock Solenoid Valve ...................................T3-7-11 Control System, Outline ......................................................... T2-2-1 Control Unit ..............................................................................T1-2-17 Control Valve ............................................................................T1-2-22 Control Valve, Outline ............................................................. T3-2-1 Control Valve Cross Section Views...................................... T3-2-5 Control Valve Hydraulic Circuit ............................................ T3-2-2

Control Valve Overview .......................................................... T3-2-3 Control by Electrical and Hydraulic Combined Circuit ....................................................................................T2-2-93 Control by Pilot Pressure from Torque Control Solenoid Valve ....................................................................T3-1-16 Control by Pump Control Pressure..................................... T3-1-8 Control by Pump Internal Delivery Pressure ................T3-1-12 Controller, Outline.................................................................... T2-1-1 Cooling Fan System ................................................................. T3-3-1 Cross Section of Transmission.............................................. T3-8-5 D Declutch Control ....................................................................T2-2-58 Declutch Operation Engine Speed Limiter ...................T2-2-28 DEF Defrosting Control ........................................................T2-3-24 DEF Injection Control ............................................................T2-3-20 DEF Supply Module ...............................................................T1-2-26 DEF Tank ....................................................................................T1-2-26 DEF Thermal Control .............................................................T2-3-26 Differential .................................................................................. T3-9-2 Differential, Operation ............................................................ T3-9-5 Differential, Principle ............................................................... T3-9-4 Differential, Purpose ................................................................ T3-9-3 Downshift Control..................................................................T2-2-54 Drain Plug............................................................................... T3-11-12 Drive Unit ..................................................................................T1-2-11 Drive Unit, Outline ................................................................... T3-8-1 Drive Unit Circuit ....................................................................T3-8-28 E ECM System ................................................................................ T2-3-2 EGR Control ..............................................................................T2-3-14 Electric Power Circuit (Key Switch: OFF)........................... T2-5-4 Electrical Component ...........................................................T1-3-11 Electrical System, Outline ...................................................... T2-5-1 Electrical System (Overview) ................................................ T1-2-5 Engine.......................................................................... T1-2-19, T1-3-1 Engine Accessories .................................................................. T1-3-5 Engine Control (ECM) .............................................................. T2-2-4 Engine Load Idle Speed Control .......................................T2-2-12 Engine Output Restriction Control (INDUCEMENT)...T2-3-30 Engine Performance Curve (QSB6.7) ................................. T1-3-4 Engine Protection Control..................................................... T2-2-6 Engine Speed Regulator For Digging .............................T2-2-20 Engine Stop Circuit ................................................................T2-5-22 Engine System, Outline .......................................................... T2-3-1 F Fan Circuit .................................................................................T2-4-42 Fan Control, Valve Control ...................................................T2-2-63 Fan Control Valve ...................................................................... T3-3-3 Fan Motor .................................................................................... T3-3-2 Fan Normal Operation ............................................................ T3-3-4 Fan Pump .................................................................................... T3-3-1 Fan Reverse Rotation .............................................................. T3-3-6 Fan Reverse Rotation Control ............................................T2-2-66 Fan Speed Control................................................... T2-2-64, T3-3-8 70Z7B F&S

INDEX Fan Valve (Option) ..................................................................T1-2-21 Final Drive .................................................................................T3-9-12 Fingertip Control Type Pilot Valve ...................................... T3-6-1 Electromagnetic Detent ................................................... T3-6-6 Operation............................................................................... T3-6-2 Outline .................................................................................... T3-6-1 First Range Engine Speed Limiter ....................................T2-2-22 Flow Rate Control Valve .......................................................T3-2-24 Flow Regulator Valve ............................................T1-2-25, T3-12-7 Forward/Reverse Idle Speed Limiter ...............................T2-2-14 Forward/Reverse Lever Priority Control .........................T2-2-48 Forward/Reverse Operation Engine Speed Limiter ...T2-2-16 Front Attachment Control Circuit .....................................T2-4-34 Front Axle ..................................................................................T1-2-12 Front Console...........................................................................T1-2-14 Front View of Transmission ................................................... T3-8-4 Front Wiper Circuit .................................................................T2-5-52 Fuel Injection Control ............................................................. T2-3-4 Fuel Injection Pressure Control .........................................T2-3-10 Fuel Injection Rate Control ................................................... T2-3-8 Fuel Injection Timing Control .............................................. T2-3-8 Fuel Injection Volume Control ............................................. T2-3-6 Fuel Injection Volume Correction Control .....................T2-3-12 Fuel Tank ....................................................................................T1-2-10 H Hazard Light Circuit (Key Switch: OFF) ...........................T2-5-34 Headlight Circuit.....................................................................T2-5-28 Horn Circuit (Key Switch: OFF) ...........................................T2-5-38 Hydraulic Circuit, Control Valve ........................................... T3-2-8 Hydraulic Component ............................................................ T1-3-6 Hydraulic System, Outline ..................................................... T2-4-1 Hydraulic Tank ........................................................................... T1-2-9 I Idle Speed-Up Control (Fan Reverse Rotation) ............T2-2-34 Idle Speed-Up Control While Driving with Load .........T2-2-32 Increasing and Decreasing Flow Rate ............................... T3-1-3 Inducement ..............................................................................T2-3-30 Insufficient DEF Level ............................................................T2-3-32 J Joystick Type Pilot Valve ......................................................... T3-6-8 Electromagnetic Detent .................................................T3-6-16 Operation............................................................................... T3-6-9 Outline .................................................................................... T3-6-8 L Lift Arm Auto Leveler Height Kickout Control .............T2-2-82 Lift Arm Auto Leveler Lower Kickout Control...............T2-2-84 Lift Arm Float Control ..........................................T2-2-96, T3-2-12 Limited Slip Differential (LSD) (Option) ............................ T3-9-8 Load-Free Engine High Idle Limiter .................................T2-2-18 Low Steering Oil Pressure Indicator Control (Option) ................................................................................T2-2-78 LSD (Option) ............................................................................... T3-9-8

M Machine Overheat Engine Speed Limiter......................T2-2-30 Main Circuit, Control Valve .................................................... T3-2-8 Main Circuit, Electrical ............................................................ T2-5-2 Main Circuit, Hydraulic .........................................................T2-4-24 Main Component ..................................................................... T1-2-3 Main Component (Overview) .............................................. T1-2-1 Main Hydraulic Pump ............................................................. T3-1-2 Main Relief Valve .....................................................................T3-2-14 Make-Up Function, Fan Valve.............................................T3-3-10 Make-Up Valve, Steering Pilot Valve .................................. T3-4-8 Malfunction of Urea SCR System ......................................T2-3-34 Manifold Valve .......................................................... T1-2-23, T3-7-7 Manifold Valve, Outline .......................................................... T3-7-1 Manual Speed Shift Control ...............................................T2-2-50 Monitor Panel ..........................................................................T1-2-18 Multiple Control Valve ..........................................................T1-2-22 Multiple Control Valve, Outline ........................................... T3-2-1 N Neutral Control........................................................................T2-2-46 Normal Operation, Fan ........................................................... T3-3-4 O ON/OFF Solenoid Valve ........................................................T3-12-4 Operation of Differential........................................................ T3-9-5 Operation of Fuel Injection ................................................... T2-3-8 Operation of Transmission ..................................................T3-8-10 Other Controls .........................................................................T2-2-71 Overload Relief Valve, Control Valve ................................T3-2-20 Overload Relief Valve, Ride Control Valve ......................T3-11-8 Overload Relief Valve, Steering Pilot Valve ...................... T3-4-6 Overload Relief Valve (with Make-Up Function) .........T3-2-16 Overrun Alarm Control .........................................................T2-2-80 P Parking Brake Accumulator ................................................T3-12-6 Parking Brake Accumulator Specifications ...................T3-12-6 Parking Brake Circuit ............................................T2-4-12, T2-5-44 Parking Brake Manual Release ...........................................T3-8-29 Parking Brake Operation Indicator Control...................T2-2-74 Parking Brake Solenoid Valve .............................................T3-12-4 Parking Brake Solenoid Valve Block .................................T1-2-23 Parking Brake Solenoid Valve Unit ...................................T3-12-3 Pilot Accumulator ...................................................................T3-7-13 Pilot Accumulator Specifications ......................................T3-7-13 Pilot Circuit, Hydraulic ............................................................ T2-4-2 Pilot Oil Filter ......................................................................... T3-12-12 Pilot Operation Control Circuit ..........................................T3-2-10 Pilot Pump.................................................................................T3-1-18 Pilot Relief Valve ........................................................................ T3-7-8 Pilot Shut-Off Circuit (Key Switch: ON) ...........................T2-5-18 Pilot Valve .................................................................................... T3-6-1 Preheating Control.................................................................T2-3-16 Principle of Differential........................................................... T3-9-4 Priority Valve ............................................................................T1-2-21 Priority Valve, Operation ........................................................ T3-5-4 70Z7B F&S

INDEX Priority Valve, Outline.............................................................. T3-5-1 Priority Valve, Structure .......................................................... T3-5-2 Propeller Shaft .........................................................................T3-12-1 Proportional Solenoid Valve ...............................................T3-7-10 Pump Control...........................................................................T2-2-39 Pump Control Circuit.............................................................T2-4-18 Pump Control Valve ...............................................................T3-2-26 Pump Delivery Pressure Sensor ........................................T3-1-18 Pump Device ............................................................................T1-2-22 Pump Device, Outline ............................................................. T3-1-1 Purpose of Differential............................................................ T3-9-3 Q Quick Power Mode Control.................................................T2-2-86 Quick Reference Matrix of Operating Solenoid Valve ........................................................................................ T3-8-9 R Radiator Assembly ................................................................... T1-2-6 Rear Console ............................................................................T1-2-16 Rear Wiper Circuit ...................................................................T2-5-54 Regulator ..................................................................................... T3-1-4 Regulator Control Function .................................................. T3-1-6 Regulator Operation .............................................................T2-5-15 Restriction Valve in Flow Regulator Valve ......................T3-12-9 Reverse Buzzer Circuit ..........................................................T2-5-40 Reverse Rotation, Fan ............................................................. T3-3-6 Ride Control (Option) ............................................................T2-2-68 Ride Control Accumulator (Option) .............................. T3-12-10 Ride Control Accumulator Specifications ................... T3-12-10 Ride Control Circuit................................................................T2-4-20 Ride Control Valve (Option) ................................................T1-2-24 Ride Control Valve, Layout ..................................................T3-11-2 Ride Control Valve, Operation............................................T3-11-4 Ride Control Valve, Outline .................................................T3-11-1 Right Console...........................................................................T1-2-15 S SCR System ...............................................................................T2-3-19 Secondary Steering Block (Option) .................................T1-2-25 Secondary Steering Check Block (Option) ................. T3-12-13 Secondary Steering Circuit (Option) ...............................T2-4-44 Secondary Steering Control (Option) .............................T2-2-90 Secondary Steering Pump (Option) ............ T1-2-25, T3-12-14 Service Brake ............................................................................T3-9-10 Service Brake Accumulator .................................................T3-7-12 Service Brake Accumulator Specifications ....................T3-7-12 Service Brake Circuit ..............................................................T2-4-10 Shift Holding Control ............................................................T2-2-60 Shockless Valve in Flow Regulator Valve ........................T3-12-8 Side View of Transmission ..................................................... T3-8-2 Single Operation Circuit.......................................................T2-4-36 Specifications ............................................................................. T1-1-1 Speed Limit Control with Power Mode OFF .................T2-2-24 Speed Shift Delay Control ...................................................T2-2-56 Start-Up Control......................................................................T2-3-22 Starting Circuit (Key Switch: START) ................................T2-5-10

Steering Accumulator ........................................................ T3-12-10 Steering Accumulator Specifications ........................... T3-12-10 Steering Column Box Circuit ..............................................T2-5-27 Steering Control Circuit........................................................T2-4-26 Steering Operation Control Circuit ..................................T2-4-14 Steering Pilot Valve, Operation............................................ T3-4-3 Steering Pilot Valve, Outline ................................................. T3-4-1 Steering Pilot Valve, Structure ............................................. T3-4-2 Steering Priority Circuit ........................................................T2-4-26 Surge Voltage Prevention Circuit......................................T2-5-16 T Torque Control Solenoid Valve ............................................ T3-7-9 Torque Converter ..................................................................... T3-8-6 Torque Converter Cooler Check Valve ......................... T3-12-11 Torque Proportioning Differential (TPD).......................... T3-9-6 Transmission .............................................................................. T3-8-8 Transmission, Front View ....................................................... T3-8-4 Transmission, Operation ......................................................T3-8-10 Transmission, Side View ......................................................... T3-8-2 Transmission Alarm Control ...............................................T2-2-72 Transmission Clutch Pack Combination ........................... T3-8-9 Transmission Control Unit (TCU).......................................T2-2-44 Transmission Control Valve .................................................T3-8-26 Transmission Pressure Test Port .......................................... T3-8-3 Turn Signal Light Circuit.......................................................T2-5-36 U Unloader Valve .......................................................................... T3-7-2 Urea SCR System .....................................................................T2-3-19 Urea SCR System, Malfunction ..........................................T2-3-34 V Variable Turbocharger Control ..........................................T2-3-17 W Washer Circuit..........................................................................T2-5-56 Wiper Circuit.............................................................................T2-5-52 Work Light Circuit...................................................................T2-5-50

70Z7B F&S

INDEX (Blank)

70Z7B F&S