DOWNLOAD PDF : Kawasaki 70ZV WHEEL LOADER SHOP MANUAL 93208-00210 (1) by www.heydownloads.com

93208-00200 June 2004

Foreword

To ensure good machine performance, reduce failures or problems, and prolong the service life of each component, it is necessary to operate the machine as is directed in the Operator and Maintenance Manual. To effectively diagnose and repair the machine, it is important to follow the guidelines laid out in this Shop Manual. Troubleshooting Measurement for Performance Check For the engine, refer to the engine Shop Manual provided by the engine manufacturer. The purpose of this manual is to provide information on the product and the correct maintenance and repair methods. Please read this manual to ensure correct troubleshooting and good repair service. This manual will be periodically reviewed and revised for more satisfactory content. If you have any opinion or requests, please inform us.

(1)

Safety Precautions The most important point in providing repair service is safety. To ensure safety, observe the general cautions described below. ●This manual is intended for properly trained and equipped service technicians. ●Any work on the machine must be performed by the trained personnel only. ●Carefully read this manual to thoroughly understand the operation method before you operate or repair the machine. ●Be sure to wear appropriate clothes and protectors, such as safety boots, hard hat and goggles. ●Place the machine on level and solid ground, and place chocks against the wheels to prevent movement. ●Remove the cable from the battery before starting the service work, and attach a "DO NOT OPERATE!" tag to the steering wheel. ●Be sure to release the internal pressure before you remove a pipe, such as the hydraulic oil, air, or engine coolant pipe. ●Be sure to apply the articulation stopper before starting work. ●While supporting the bottom of the chassis using a jack, be sure to support the chassis using the blocks. ●When the boom or bucket is raised or when a unit is lifted by a crane, be sure to place a stand or adequate cribbing under the unit to prevent unexpected dropping. ●Do not start to work in an enclosed area if adequate ventilation is not provided. ●To remove a heavy unit (20kgf (40 lbs) or more), be sure to use a crane or other lifting tool. ●Just after stopping operation, be careful not to directly touch a hot component. You may get burned. ●Contact tire manufacturer's local dealer for tire servicing and changing. ●Always store the tools in good condition, and use them properly. ●Keep the work area clean. Clean up spills immediately. ●Avoid the use of flammable solvents and cleaners. ●When working outdoors keep work areas, ladders, steps, decks and work platforms clear of snow, ice, and mud. ●Use safe work platforms to reach higher areas of the machine. (2)

Safety Symbols An accident may occur if you disregard safety rules. In this manual, several expressions are used according to levels of danger for inspection and repair work as shown below. Read the work procedures and cautions described in this manual, and take preventive measures against possible problems before starting service work.

DANGER This danger symbol identifies special warnings or procedures which, if not strictly observed, will result in death or serious injury.

WARNING This warning symbol identifies special warnings or procedures which, if not strictly observed, could result in death or serious injury.

CAUTION This caution symbol identifies special instructions or procedures which, if not strictly observed, may result in minor or moderate injury.

IMPORTANT This important symbol identifies special instructions or procedures which, if not correctly followed, may result in serious machine damage.

We cannot predict all possible accidents or incidents that may occur during service work. Therefore, an accident that is not specifically mentioned in this manual may occur. To protect yourself from all accidents, be careful when doing service work.

(3)

Symbols For safe and effective service work, the following symbols are used for notes and useful information in this manual. Symbol

Item

Description

Reference

Weight

Shows the condition or procedure that will be useful or efficient in doing service work. Shows the weight of a part or unit. The weight should be considered in selecting wire rope or cable for slinging work or determining the working posture.

Shows the tightening torque of a section that Tightening should be carefully tightened during assembly torque work.

Coating

Shows the type of coating or adhesive and the coating section.

Oil or water supply

Shows the oil or water supply port and the refill amount.

Drainage

Shows the oil or water drain port and the drain amount.

IMPORTANT If the specified conditions are not satisfied or the specified procedure is not observed, there is a strong possibility that the product will be damaged or the performance of the product will be reduced. The message shows the preventive measures.

Abbreviation To save space, abbreviations are used in sentences. To understand the contents of this manual, refer to the following abbreviation list. E/G ………Engine T/C ………Torque converter T/M ………Transmission SOL ………Solenoid valve SW ………Switch F …………Front or Forward QUAD ……Quick Up and Down Shift A/M ………Auto/Manual

B …………Battery R …………Rear or Reverse RH …………Right hand side LH …………Left hand side H …………High L …………Low GND ………Ground OPT ………Option Assy ………Assembly (4)

1st ………1st speed 2nd ………2nd speed 3rd ………3rd speed 4th ………4th speed DD ………Dynamic Damper M/C ………Machine min-1 ………RPM

Hydraulic Pressure Test Kit General Kawasaki recommends that each service department have at least one in the shop and one for use on each service truck that is equipped to work on Kawasaki loaders.

Detail Test kit part number: ZZKL3002A It consists of the following parts. Item

Qty.

Part number

PGLA63NB500S

Description

Notes

Remarks

Gauge

500 PSI

For T/M pressure check

PGLA63NB1000S

Gauge

1000 PSI

For Hyd. pilot pressure check For brake valve pressure check

PGLA63NB6000S

Gauge

6000 PSI

For Hyd. main pressure check For steering pressure check For unloader valve pressure setting

ABH121504N

1/4" NPT adapter

H1215B0101144

Hose 144"

TKCC1

Carry case

Note: To adapt from our quick connect test fittings [38900-23510-7] to a gauge that has male 1/4" NPT, order one of each of the items marked "X" above.

(5)

MEMO

TROUBLESHOOTING ....................................................01-1 MEASUREMENT FOR PERFORMANCE CHECK .........03-1

MEMO

Troubleshooting 01 Cautions Regarding Troubleshooting .........................................................01-3 How to Use Quick Troubleshooting Table ..................................................01-4 Safety Precautions ......................................................................................01-5 Quick Troubleshooting Table Torque Converter and Transmission Group 1. Machine does not move in any shift lever position ...........................01-6 2. Machine does not move at a certain shift lever position ...................01-7 (or: Machine moves only in a certain shift lever position) 3. Machine moves at the neutral position .............................................01-8 (Example: Machine moves forward at the neutral position) 4. Large shock at starting or changing speeds / direction ....................01-9 5. Large time lag at starting or changing speed / direction .................01-10 6. Low power .......................................................................................01-11 (Defective torque converter or transmission) 7. Torque converter oil is overheating ................................................01-12 8. Machine moves reverse when starting to climb up on a slope using inching brake ..........................................01-13 9. Automatic speed change is not possible ....................................... 01-14 10. QUAD switch does not work .......................................................... 01-15

01-1

Hydraulic Group 1. Boom and/or bucket do not move ...................................................01-16 2. Boom and/or bucket have low power, or move too slowly ............. 01-17 3. Excessive cylinder drift .................................................................. 01-18 4. Boom and/or bucket are spongy ......................................................01-19 (Holding bucket against the ground is not possible) 5. Bucket positioner (kick out) does not work .................................... 01-20 6. Steering is not possible or hard to steer ........................................ 01-21 7. Machine sways, or has a shock during steering ............................ 01-22 8. Abnormal noise in hydraulic system .............................................. 01-23 9. Others ..............................................................................................01-24 Brake Group 1. Brake does not work well (In the worst case, the brake does not work at all) ........................ 01-25 2. Brake is dragging when released .................................................. 01-26 3. Stepping on the brake pedal sounds the buzzer ........................... 01-27 4. Accumulator pressure does not rise, or too slow in rising ............. 01-28 5. Parking brake does not work ......................................................... 01-29 (or: Releasing the brake is not possible) Electrical Group 1. Instrument panel does not indicate properly .................................. 01-30 2. Breaker of the transmission controller is turned off ....................... 01-31

01-2

Cautions Regarding Troubleshooting ● Important points The important points for troubleshooting is to carefully read the operation manual and shop manual to get enough information on the operation, circuits, structure, and function of each component. If you have enough knowledge of each component and system, you can easily determine the cause of the problem. There may be various causes for each problem, therefore experience will be needed to determine which is the actual cause of the problem. it is necessary to know the normal operation of each component. In addition, it is also important to know the abnormal condition when a problem occurs. This chapter shows various examples of past problems, and describes possible causes and remedies for each problem.

The following questions will be helpful in determining of the cause. Answer the questions to prevent an incorrect diagnosis. 1. Did the problem occur suddenly? 2. When did the operator notice the problem? 3. Is there any past problem that may be the cause of this problem? 4. When the problem occurred, what kind of work was the operator doing? 5. Has the machine had the same kind of problem before? 6. Has the machine been repaired or inspected recently? 7. Does the machine have any other problem?

● Troubleshooting

● Before starting troubleshooting To prevent incorrect diagnosis, talk with the persons concerned, particularly with the operator, to get enough information on the problem. If possible, check the machine by repeating the symptom. If the problem cannot be repeated, do not provide any repair service. For instance, assume that the operator complains that the boom power is low, and the rim-pull is also low. In this case, there are two possible causes ; low hydraulic power and low rim-pull. The remedies against both causes are much different from each other. If you hastily determine the wrong cause without checking the actual condition of the problem, it will take too much time and expense to solve the problem. As a result, you will not be trusted by the user.

01-3

- Check before determination of cause A problem may be caused by poor daily maintenance, such as lack of grease, low or improper oil or a clogged filter. Be sure to check the machine for oil level, appearance, unpleasant odor, etc. to prevent time loss due to other unnecessary tests. - Inspection procedure As a rule, check the easy-to-be-repaired system first (excluding the cases where the cause can be easily determined based on the past experiences). This machine is controlled by electrical, hydraulic, and mechanical systems. The most easy-to-berepaired system is the electrical system. Check the electrical system first. If no problem is detected in the electrical system, check the hydraulic system, and then the mechanical system.

How to Use Quick Troubleshooting Table To immediately determine the cause of the problem without disassembling parts, use the quick troubleshooting table. From the problem explained by the user and the check points written in the table, you can immediately determine the cause of the problem.

● How to use quick troubleshooting table (1) According to the problem explained by the user, open the quick troubleshooting table to the page where the corresponding problem is described. (2) Check the machine according to the "Symptoms/check point" field in the table. Start from the most easily checked point. (3) Operate the machine, and write the check marks " " in the corresponding circles " " if the problem occurs. (4) Generally, the possible cause that has many check marks will be actual cause. If two or more possible causes have several check marks, check each possible cause to prevent an incorrect diagnosis. In this case, start from the most easily checked item.

01-4

Safety Precautions

70ZV

TROUBLESHOOTING 01

Safety Precautions WARNING

DANGER

Service work under the machine may cause an accident resulting in injury or death. To prevent such an accident, be sure to observe the following items. - Park the machine on level ground. - Apply the parking brake. - Block the tires with chocks to prevent the tires from moving. - Stop the engine. - Give signals to the person in the cab during the work.

Entering the articulation area of the machine body while the engine is running may cause severe accidents. Make sure to stop the engine, pull out the starter key, and attach a "DO NOT OPERATE!" tag to the cab before entering the articulation area.

WARNING Unexpected movement of the machine may cause an accident resulting in injury or death. Therefore, to provide repair service with the engine running, be sure to observe the following items. - Park the machine on level ground. - Apply the parking brake. - Block the tires with chocks to prevent the tires from moving. - Determine the signals between the service man. - Prohibit any person from walking into dangerous areas. - Near articulation areas of the machine - Under the machine - Around the engine - In front of or behind the machine

CAUTION Do not touch the fan or V-belt of the engine or a high-temperature section if the engine is running. An accident resulting in injury may occur. Be sure to stop the engine before you open the side cover of the engine room. Avoid high temperature components even when the engine is stopped.

CAUTION Be careful not to be burnt by bursting high pressure oil. Release the pressure remaining inside the circuit and open the cap of the hydraulic oil tank before removing the plug from the pressure measurement port so that the internal pressure of the hydraulic oil tank is released and burst of the high pressure oil can be prevented.

WARNING Standing under the boom or bucket during service work is dangerous. An accident resulting in injury or death may be caused. To prevent such an accident, be sure to observe the following items. - Park the machine on level ground. - Apply the parking brake. - Block the tires with chocks to prevent the tires from moving. - Place a stand under the boom to support it. - Apply the safety look of the boom and bucket control lever provided in the cab. - Remove the starter key, and attach a "DO NOT OPERATE!" tag to the cab. 01-5

Torque Converter and Transmission Group

70ZV

TROUBLESHOOTING 01

Pump produces an abnormal(shrieking)noise

Pump is extremely heated

If the breaker of the controller is turned ON, the breaker will immediately turn OFF again

Controller LED "I" indicator is ON

Filter of the torque converter is clogged

Temperature of the torque converter oil is too high

Torque converter oil becomes milky and cloudy in color

Possible cause

Low clutch oil pressure at all the shift lever positions

(1) Check that the parking brake is released. (2) Check the torque converter oil level. (3) Check the fuse of the controller system. (4) Check that the circuit protector of the controller is ON. (5) Check the 70A fusible link. (If the 70A fusible link is off, no electrical circuits will operate except horn circuit and hazard flasher [opt.].)

Symptoms/check point

Check before starting work

The controller LED "X" indicator is OFF

1. Machine does not move in any shift lever position

Setting the T/M(transmission)cut-off switch to OFF allows normal operation

Torque Converter and Transmission Group

Solution

Air drawn into suction line of the torque converter pump

Tightening hose band

Defective torque converter pump

Pump replacement

Damaged torque converter

Disassembly & repair

Sticking clutch pressure regulator valve

Disassembly & repair

Malfunctioning inching pressure switch

Switch replacement

Defective controller Neutral relay, controller fault relay, parking switch wiring short circuited. Restricted suction line - pinched, plugged, or internally defective.

Controller replacement Repairing wiring Replace hose

01-6

2. Machine does not move at a certain shift lever position (OR:Machine moves only in a certain shift lever position)

Possible cause

01-7

Machine may move even when shift lever is in "NEUTRAL"

Controller IN and OUT LED do not correspond with each other, controller failure light on dash is ON

70ZV

Breaker of the controller will be turned off at a certain shift lever position

Controller input LED will not light at a certain shift lever position

Clutch can be engaged at a certain shift lever position, though the clutch will not be engaged at any other position

At a certain shift lever position, the controller input LED is turned on and will not go out

Clutch oil pressure is always high despite shift lever position and output LED

Even when pressing solenoid valve, machine does not move

24V power is not supplied to the solenoid valve (output LED OK)

Resistance of the solenoid valve coil is infinite Ω

Clutch oil pressure is low at a certain position only. At all the other positions, the pressure is normal

Torque converter oil looks and smells as if it was scorched (black)

Machine moves at a certain shift lever position, but hesitates to move at any other positions

Machine does not move at a certain shift lever position, but moves at all the other positions

Symptoms/check point

Torque Converter and Transmission Group TROUBLESHOOTING 01

Solution

Clutch slipping Disassembly & repair

Seized clutch Disassembly & repair

Clutch oil leaks internally Disassembly & repair

Coil of clutch solenoid valve is defective Solenoid valve replacement

Harness of clutch solenoid valve disconnected Repair cable

Clutch solenoid valve sticking in OFF position Solenoid valve replacement

Clutch solenoid valve sticking in ON position Solenoid valve replacement

Shift lever switch sticking in ON (regardless of position) Shift lever replacement

Shift lever switch sticking in OFF (regardless of position) Shift lever replacement

Damaged clutch solenoid valve diode

Solenoid valve replacement

Defective controller

Controller replacement

Short circuited clutch solenoid or wiring

Repair cable

Controller output LED "F" will go out when shifted to reverse (output LED "R" will not turn on).

Oil is black and smells scorched

Possible cause

Controller input LED "F" indicator is on and will not go out

(1) Check that the ground is level. (2) The machine may not move at low idle (LI) but starts to move as the engine speed is increased.

Symptoms/check point

Check before starting work

TROUBLESHOOTING 01

Controller output LED "F" indicator is on and will not go out

3. Machine moves at the neutral position (Example: Machine moves forward at the neutral position)

When the lever is shifted to the reverse position, the machine does not move reverse (as if the brake is applied)

70ZV

When the lever is shifted to the forward position, the machine moves forward

Torque Converter and Transmission Group

Solution

Seized clutch on forward side *

T/M disassembly and repair

Malfunctioning forward solenoid valve (sticking at ON position) * Defective controller(malfunctioned after outputting "F") *

Solenoid valve replacement

Defective shift lever (switch stuck in "F" position) *

Shift lever replacement

Controller replacement

Remarks

* The same possible cause but involving the reverse clutch or circuit could occur with the opposite symptoms.

01-8

Torque Converter and Transmission Group

70ZV

TROUBLESHOOTING 01

Malfunctioning piston in regulator valve

Line filter is clogged

Temperature of the torque converter oil is too high

Main oil pressure rises too quickly at all the shift lever positions

Large shock at a certain shift lever position only

Symptoms/check point Possible cause

Large shock at all the shift lever positions

4. Large shock at starting or changing speeds / direction

Solution

Damaged or worn clutch disk

Disassembly&repair T/M disassembly and repair

Defective accumulator

Disassembly&repair

01-9

Torque Converter and Transmission Group

70ZV

TROUBLESHOOTING 01

Time lag just after using the inching brake

Clutch oil pressure is too low or rises too slowly at a certain shift lever position only

Large time lag at a certain shift lever position only

Main oil pressure is too low at all the shift lever positions

Main oil pressure rises too slowly at all the shift lever positions

Possible cause

Large time lag at all the shift lever positions

Symptoms/check point

5. Large time lag at starting or changing speed / direction

Solution

Defective torque converter pump

Pump replacement

Malfunctioning piston in main accumulator Main accumulator spring breakage or excessive wear

Disassembly & repair Spring replacement

Internally clutch oil leakage

T/M disassembly and repair

Malfunctioning inching pressure switch

Switch replacement

Defective 1st or 2nd speed accumulator

Disassembly & repair

Defective solenoid valve

Solenoid valve replacement

01-10

Torque Converter and Transmission Group

70ZV

TROUBLESHOOTING 01

Pump produces an abnormal(shrieking)noise

Pump is extremely heated

Clutch oil pressure is too low at a certain shift lever position

Silver powder (Aluminum) is on the line filter and strainer

Torque converter oil is milky and cloudy in color

Torque converter oil is discolored or smells burnt (scorched)

Temperature of the torque converter oil is too high

Large time lag at a certain shift lever position only

Output power is low at a certain shift lever position only

Possible cause

Output power is low at all the shift lever positions

(1) Check the parking brake and service brake for dragging. (2) Check the torque converter oil level. (3) Check that no unusual load is applied to the hydraulic line(like excessive pilot pressure). (4) Check that the engine speed is standard value.

Symptoms/check point

Check before starting work

Machine moves even if the shift lever is set to the neutral position*

6. Low power (Defective torque converter or transmission)

Solution

Air drawn into suction line of torque converter

Tightening suction hose band

Broken torque converter turbine and pump

T/C disassembly and repair

Torque converter internal pressure too low

Regulator valve check

Seized clutch

T/M disassembly and repair

Clutch slipping

T/M disassembly and repair

Internally leaking clutch oil

T/M disassembly and repair

Remarks

* if the seized clutch is Forward or Reverse clutch.

01-11

TROUBLESHOOTING 01

Parking brake is excessively hot/discolored

Less difference in torque converter oil temperature between cooler inlet and outlet

Pump produces an abnormal(shrieking)noise

Pump is extremely heated

Output power is too small at a certain shift lever position

Foreign material is on the filter-especially silver powder (Aluminum)

Torque converter oil is discolored or smells burnt (scorched)

Torque converter inlet pressure is too low

Clutch oil pressure is too low

Possible cause

Torque converter oil is milky and cloudy in color

(1) Check the torque converter oil level. Oil level too high. (2) Check the engine coolant for overheat. (3) Check the pressures - adjust to specification. (4) Be sure the covers under the radiator are in place.

Symptoms/check point

Check before starting work

Machine does not move at a certain shift lever position (or dragging is felt)

7. Torque converter oil is overheating

Engine speed at no load or during stall test is too low

70ZV

Thermometer in T/C out line indicates less than 250°F/120°C when gauge or light indicates overheat

Torque Converter and Transmission Group

Solution

Air drawn into suction line of torque converter

Tightening hose band

Internally torque converter leakage

T/C disassembly and repair

Damaged torque converter

T/C disassembly and repair

Torque converter pump discharge amount too small

T/C pump disassembly and repair

Seized clutch

T/M disassembly and repair

Clutch slipping

T/M disassembly and repair

Scale deposited in water line of torque converter cooler

Cooler cleaning

Restricted suction line-pinched, internally defective

Replace hose

Wrong oil viscosity is used

Replace w/proper oil

Service or parking brake dragging

Test/repair brake circuit

Operator is using too high gear for loading

Train operator

Incorrect indication of gauge (no alarm)

Test/replace gauge or sender

Alarm switch defective (gauge in green zone)

Replace switch

Contamination in oil cooler (oil side)

Replace cooler

Engine speed too low / Engine power too low

Test engine performance

01-12

70ZV

Symptoms/check point

8. Machine moves reverse when starting to climb up on a slope using inching brake

Possible cause

After pedal release, too much time is required to turn off the controller LED"I" indicator

Torque Converter and Transmission Group

TROUBLESHOOTING 01

Solution

Large time lag in clutch engagement

Refer to description of time lag in measurement & performance section

Delay in resetting inching pressure switch

Switch replacement

01-13

Speed is properly increased on a downward slope

Speed is fixed to 3rd speed, and is not increased to 4th speed

Possible cause

Controller input LED "A" indicator does not light

(1) Manually change the speed from 1st speed to 3rd speed. If manual speed change is impossible, refer to "Machine does not move at a certain shift lever position." (2) Confirm that the automatic speed change is not possible. Operate the machine on a flat hard open surface after the oil is warmed to operating temperature. Very cold transmisson oil will prevent automatic shifting due to drag inside the transmission.

Symptoms/check point

Check before starting work

Speed is fixed to 2nd speed, and automatic speed change is not possible

9. Automatic speed change is not possible

One or more planetaries are excessively hot/parking brake is hot or discolored

TROUBLESHOOTING 01

Controller LED for machine speed does not change even if machine speed is changed

70ZV

Actual speed increase or reduction does not correspond with the set speed

Torque Converter and Transmission Group

Solution

Defective shift lever "A" position or defective wiring to controller

Shift lever replacement or repairing wire

Damaged speed sensor or disconnected sensor

Sensor replacement or repairing wire

Speed sensor signal output error or improperly adjusted speed sensor Defective controller

Sensor replacement or readjustment

Low machine speed (engine output power too low)

Inspection & repair

Parking or service brakes dragging

Test/repair brake circuit

Controller replacement

01-14

10. QUAD* switch does not work * (Quick Up shift And Down shift Switch)

(1) Check that the QUAD switch is being used only at the 2nd forward/reverse speed position. The QUAD switch will shift from 2nd to 1st speed and then back to 2nd when the machine is in "2" manual position or in "A" (Automatic) position. At other positions, shifting down is not possible. (2) Check the fuses.

Possible cause

Symptoms/check point

Check before starting work

TROUBLESHOOTING 01

Controller input LED "S" indicator lights when the QUAD switch is turned on

70ZV

Controller input LED "S" indicator does not light when the QUAD switch is pushed

Torque Converter and Transmission Group

Solution

Defective switch

Switch replacement

Disconnected switch or wiring

Repair wire

Defective controller

Controller replacement

01-15

Hydraulic Group

70ZV

TROUBLESHOOTING 01

Multiple control valve

Pump

Pump is extremely heated

Main relief valve produces a noise

Bucket moves if the overload relief valves are exchanged with each other *

Cylinder does not operate, though oil is discharged from the return port

After warm-up, it is possible to operate the bucket and boom

Pilot relief pressure is too low

No pilot relief pressure built

Main relief pressure is too low when the boom or bucket is operating

No main relief pressure built (or pressure is very low)

Either the boom or bucket does not move

Possible cause

Steering is not possible either

(1) Check the oil level. (2) Check that the loading control lock lever is fully released. (3) Check that the pilot valve inline filter is not clogged.

Symptoms/check point

Check before starting work

Boom and bucket do not move normally while the engine runs idle but appears to move normally while it runs at full speed

1. Boom and/or bucket do not move

Boom and bucket move with no load, though they do not move when loaded

Hydraulic Group

Solution

Broken pump drive shaft

Pump replacement

Internally damaged steering pump

Disassembly & repair

Internally damaged main pump

Disassembly & repair

Internally damaged pilot pump

Disassembly & repair

Main relief valve internal oil leakage or low setting pressure

Disassembly & readjustment

Overload relief valve internal oil leakage or low setting pressure

Disassembly & readjustment

Multiple control valve spool sticking

Plunger replacement

Defective valve assembly reducing valve

Disassembly & readjustment

Internally damaged cylinder

Disassembly & repair

Remarks

* Exchange of the overlord relief valve means that the valves should be changed between the rod and bottom sides.

01-16

Hydraulic Group

70ZV

TROUBLESHOOTING 01

Pump makes noise (shrieking)

Oil is foamy or milky looking after operation.

Bucket drifts down when full

Pump is extremely heated

Main relief valve produces a noise

Only bucket "roll back" operation is abnormal

Either the boom and bucket does not operate properly

Both the boom and bucket do not operate properly

Possible cause

Steering system operates properly

(1) Check the oil level. (2) Check that the loading control lock lever is fully released. (3) Check that the engine speed is at standard value. (4) Check that the machine does not move if the shift lever of the transmission is at the natural position. Dragging/seized clutches reduce power available to hydraulics. (5) Check that the machine rolls freely in neutral. If the brakes, service or parking, drag it reduces the power available to hydraulics when the machine is moving.(Static testing will show normal hydraulic power and speed.) (6) Check that the pilot valve filter is not clogged.

Symptoms/check point

Check before starting work

Steering system does not operate properly (too slow or weak)

2. Boom and/or bucket have low power, or move too slowly

Solution

Internally damaged steering pump

Disassembly & repair

Internally damaged main pump Main relief valve internal oil leakage or low setting pressure Internal oil leakage from overload relief valve for bucket bottom side

Disassembly & repair Disassembly & readjustment Disassembly & readjustment

Internally damaged cylinder

Disassembly & repair

Oil is cold, wrong oil viscosity (too thick)

Warm up hydraulics Replace oil w/proper oil

Suction side air leak-clamp, hose, o-rings

Check & repair suction line

Suction line pinched or internally defective

Check & repair suction line

Defective valve assembly reducing valve Bucket or boom spool does not move smoothly

Disassembly & readjustment Disassembly & repair

01-17

TROUBLESHOOTING 01

The maximum drift rate is measured according to

Excessive drift of bucket

Possible cause

Excessive drift of boom

Symptoms/check point

instructions on "Measuring Cylinder Drift".

In the case that the overlord relief valve is switched or replaced, excessive drift stops

3. Excessive cylinder drift

Front wheels drift down when the front wheels are lifted off the ground by means of the boom cylinder

70ZV

When the piping for cylinder rod side is removed, pressurized oil spouts out *

Hydraulic Group

Solution

Internal boom cylinder piston seal oil leakage

Seal replacement

Internal bucket cylinder piston seal oil leakage

Seal replacement

Internal oil leakage from multiple control valve main spool

Disassembly & repair

Internal oil leakage from multiple control valve overload relief valve

Disassembly & repair

Remarks

* This test may cause a serious accident. The test must be done carefully.

01-18

Boom is spongy just after quick lowering

Boom cannot support the lifted front wheels, or the lifted front wheels soon drop

Boom and bucket are strong enough if the engine runs at the full speed while dumping or lowering

Possible cause

Bucket is spongy just after dumping

Symptoms/check point

(1) Be sure the boom control lever is not pushed fully forward into the "FLOAT" position.

Overload relief pressure is too low

Check before starting work

In case that the overload relief valves are switched*, the boom and bucket are strong enough to support the front wheels.

4. Boom and /or bucket are spongy (Holding bucket against the ground is not possible-front wheels off the ground)

TROUBLESHOOTING 01

Bucket cannot support the lifted front wheels, or the lifted front wheels soon drop

70ZV

During digging operation, the bucket tilts back even though the lever is at the neutral position

Hydraulic Group

Solution

Internal oil leakage from overload relief valve for bucket rod side Internal oil leakage from make-up valve for bucket rod side

Disassembly & repair

Make-up valve does not open on bucket rod side**

Disassembly & repair

Internal oil leakage from make-up valve for boom rod side Make-up valve opening impossible on boom rod side

Disassembly & repair

* Regarding check point above, switching the overload relief valves means that the valves should be changed between the rod and bottom sides of the bucket circuit. ** If an oversized attachment (very large bucket, Quick Coupler attachment, log forks etc.) is used the dumping speed and force may be too great. It requires the use of a slow dump or cushion dump valve option. Failure to install and properly

Remarks

adjust the dump valve to reduce the dumping speed and force can result in damage to the hoist arm and linkage.

01-19

(1) Check the fuses. (2) Check that the distance between the proximity switch and detection bar is properly adjusted. 5 ± 2mm (0.2 ± 0.08in) (3) Check all the connectors of the electrical power line to be sure they are properly connected.

Possible cause

Symptoms/check point

Check before starting work

LED lamp of the proximity switch does not light (starter switch ON & metal plate in front of proximity switch face)

5. Bucket positioner (kick-out) does not work

TROUBLESHOOTING 01

Magnet coil resistance value is indicated as infinity or 0 Ω

70ZV

Remove the connector of the proximity switch, and connect the wire harness (brown/white), from the pilot valve, of the connector on the chassis side to the ground. Check that the lever is held properly.

Hydraulic Group

Solution

Defective proximity switch

Proximity switch replacement

Broken detent solenoid coil inside pilot valve

Magnet replacement

Disconnected electrical power line

Repair

01-20

TROUBLESHOOTING 01

Overload relief pressure is too low

Steering relief pressure is too low in one direction only

Increasing the engine speed enables smooth operation

Steering is not possible at both the idling and full speeds

Steering relief valve produces a noise

Steering is possible in either the right or left direction

Boom is too slow in rising

Steering wheel is too loose (too light)

Possible cause

Steering wheel does not rotate or is hard to rotate

(1) Check the oil level in the hydraulic tank. (2) Check that the stop bolts for the stop valves are properly adjusted. (3) Check operating conditions. Full brake application & heavy loading may create hard steering even when steering system is normal. (4) Measure steering wheel force to see if it is greater than normal. (5) Check that the pilot valve inline filter is not clogged.

Symptoms/check point

Check before starting work

Steering is not possible (or hard) in both the right and left directions

6. Steering is not possible or hard to steer

Pump is extremely heated

70ZV

If the overload relief valves are exchanged*, steering problem switches sides

Hydraulic Group

Solution

Internally damaged Orbitrol ®

Disassembly & repair

Sticking stop valve spool Internally damaged steering pump (deteriorated performance)

Disassembly & repair

Malfunctioning steering valve or flow control spool

Disassembly & repair

Defective main relief valve

Disassembly & repair

Defective overload relief valve

Disassembly & repair

Defective steering cylinder

Disassembly & repair

Suction line is pinched or internally defective

Check & repair

Cold oil / viscosity too thick for weather

Warm up hydraulics Replace oil w/proper oil

Defective steering pilot line reducing valve

Disassembly & repair

* Regarding check point above, exchange of the overload relief valve means that the valves should be changed between the left and right sides. The problem will switch sides also (weak steering to the left will, after exchange, become

Remarks

weak steering to the right).

01-21

Hydraulic Group

70ZV

TROUBLESHOOTING 01

Steering cylinders or circuit recently repaired

Shock is noticed only when steering fully to right or left

Shock is applied to the machine after quick steering

Machine sways after quick steering

Possible cause

While the machine is travelling straight, the machine sways even if the steering wheel is held steady

Symptoms/check point

7. Machine sways, or has a shock during steering

Solution

Loose steering cylinder pin *

Pin replacement or shim add

Tire having different diameter

Use of equal diameter tires

Large difference in air pressure of tires

Air pressure adjustment

Steering stopper bolt or bolts misadjusted or missing

Adjust stopper bolts

Air trapped in steering cylinders

Steer full L & R several times to purge air

* Have an operator quickly move the steering wheel right and left a few degrees. If the cylinder pin moves back & forth

Remarks

replace the pin & bushing. If the cylinders jump up & down add shims.

01-22

Hydraulic Group

70ZV

TROUBLESHOOTING 01

Noise may vary with engine speed or circuit being used

Increasing the engine speed emits a whining sound-Hydraulics slow

Possible cause

Pump emits a shrieking sound

Symptoms/check point

8. Abnormal noise in hydraulic system

Solution

Air drawn into pump suction line

Hose band tightening and inspection

Internally broken pump High-pressure hose contact with chassis - loose sheet metal Suction hose pinched or internally defective

Hose clamp check and repair

Suction line or strainer restricted

Drain & inspect tank

Disassembly & repair

Inspect or replace hose

01-23

Defective (incompletely closed) load check valve in multiple control valve boom line Defective (incompletely closed) load check valve in multiple control valve bucket line

Engine cooling water (torque converter oil) overheats. (Fan motor does not switch to high speed.)

Oil milky white

Hydraulic cylinder packings leak repeatedly

Hydraulic oil is mixed with the torque converter oil

Hydraulic oil is foaming

Boom or bucket control lever is too tight or too loose

Possible cause

When the boom lever is switched from"DOWN" to "NEUTRAL" , the boom will continue to lower*

Symptoms/check point

9. Others

TROUBLESHOOTING 01

When the bucket lever is set to "Roll-back" position, the bucket will be dumped slightly down first and then tilt back

70ZV

When the boom lever is set to "UP" position, the boom will drop slightly first and then rise

Hydraulic Group

Solution Disassembly & repair Disassembly & repair

Clogged orifice of adapter in boom line* Malfunctioning multiple control valve or pilot valve is sticking

Disassembly & repair

Air drawn into pump suction line

Tightening hose band

Damaged hydraulic oil pump

Pump disassembly and repair

Excessive hydraulic oil temp, due to cooler problems or improper operation

Test cooling Change operation

Water in hydraulic oil

Drain & replace oil

Defective thermo sensing valve

Disassembly & repair

Defective relief valve

Check & repair

Disassembly & repair

* Very cold or thick oil will also cause this symptom. If the problem stops when the oil warms up or the proper viscosity oil is used the orifice is normal. Clogged adapter orifice will cause slow boom response in both up and down

Remarks

directions.

01-24

Brake Group

70ZV

TROUBLESHOOTING 01

Brake warning lamp is turned on and buzzer is turned on

Machine turns when the brake is applied suddenly (the steering wheel slips from our hands)

Brake is hard to work when the right pedal is depressed

Possible cause

When the pedal is pressed, the brake oil pressure greatly differs between the front axle brake and rear axle brake.

(1) Check the Nitrogen gas pressure in the accumulator. (2) Check the brake piping for leakage

Symptoms/check point

Check before starting work

Both the right and left pedals have low braking resistance when pressed

1. Brake does not work well (In the worst case, the brake does not work at all)

Measure the wear of the brake disk using calipers. The obtained wear value is less than the specified limit value.

Brake Group

Solution

Worn brake disk

Disassembly & repair

Defective accumulator

Disassembly & repair

Sticking brake valve spool

Disassembly & repair

Damaged brake oil pipe

Pipe replacement

Improperly aligned oil passages inside wheel hub

Remove & realign

Damaged brake piston seals one wheel

Seal replacement

01-25

Brake Group

70ZV

TROUBLESHOOTING 01

2. Brake is dragging when released

Manual rotation of the tire is not possible

Either the left or right wheel causes dragging

Either the front or rear axle causes dragging

Possible cause

Manual rotation of the tire is possible

(1) Check that the cover of the planetary gear is too hot(more than 100°C [212°F]). (2) Jack up the tires, and check that manual rotation of the tire is not possible.

Symptoms/check point

How to check dragging:

Solution

Stepping on brake pedal during traveling (Riding the brakes)

Instruction for operator

Insufficient return of brake pedal

Disassembly & repair

Incomplete air bleeding from the brake oil circuit

Disassembly, repair, and air bleeding

Distorted brake disk due to seizure

Disassembly & repair

Insufficient return of brake piston

Disassembly & repair

Defective brake valve

Disassembly & repair

01-26

Brake Group

70ZV

TROUBLESHOOTING 01

3. Stepping on the brake pedal sounds the buzzer

Parking brake is not released

External pipe is oily, leaking

Too much time is required for accumulator gas charging

Unloader valve on-load pressure is too low

Possible cause

Buzzer sounds when the pedal is repeatedly depressed

(1) Check the accumulator Nitrogen gas pressure (2) Step on the pedal, and check that oil is not leaking.

Pedal resistance is too low when depressed

Check before starting work:

Symptoms/check point

(1) Low accumulator pressure [3.9MPa (40kgf/cm2) (569 psi) or less].

Buzzer sounds each time the brake pedal is stepped on

Conditions for buzzer sounding:

Solution

Insufficient Nitrogen gas pressure in main accumulator

Adjust gas pressure

Low unloader valve switching pressure

Inspection & readjustment

Delay in working unloader valve

Inspection & readjustment

Large amount of oil leakage from brake piping

Disassembly & repair

Defective low oil pressure warning switch

Replace switch

Defective pilot pump

Replace pump

Brake oil piping damaged or loose

Repair / tightening

01-27

Brake Group

70ZV

TROUBLESHOOTING 01

Low accumulator pressure in a certain accumulator only

Possible cause

Low accumulator pressure in all two accumulator

Symptoms/check point

4. Accumulator pressure does not rise, or too slow in rising.

Solution

Low unloader valve switching pressure

Inspection & readjustment

Defective unloader valve

Disassembly & repair

Internally damaged accumulator

Disassembly & repair

Defective pilot pump

Replace pump

01-28

Heavy movement of solenoid valve manual release knob

Coil of the solenoid valve has extremely high or zero resistance

Turning on /off the parking brake switch activates the link under the cylinder

Possible cause

Turning on /off the parking brake switch causes a solenoid valve emitting noise

(1) Check the fuses of the electrical system. (2) Check the main accumulator pressure. If the low brake pressure warning swich senses low accumulator pressure the parking brake will not release.

Symptoms/check point

Check before starting work:

TROUBLESHOOTING 01

Turning the manual release knob of the solenoid valve counterclockwise releases the parking brake*

5. Parking brake does not work (or: Releasing the brake is not possible)

Parking brake remains unreleased

70ZV

Brake does not work even if the parking switch is turned to "ON" position

Brake Group

Solution

Defective coil of parking solenoid valve

Solenoid valve replacement

Sticking spool of parking solenoid valve

Solenoid valve replacement

Oil leaking from line between solenoid valve and parking brake spring chamber

Inspection & repair

Defective parking brake switch

Switch replacement

Disconnected or defective electrical line

Repair cable

Sticking parking brake spring chamber

Inspection & repair

Defective link between parking brake spring chamber and brake drum Worn brake lining

Inspection & repair Readjustment or replace

Accumulator pressure in main accumulator is low

Inspection & repair

Defective low oil pressure warning switch

Switch replacement

Remarks

* Before doing this block the wheels so the machine can not roll unexpectedly.

01-29

Electrical Group

70ZV

TROUBLESHOOTING 01

T/M(transmission) solenoid valve does not operate based on the speed set by the shift lever

Speed indicated on the instrument panel does not correspond with the speed set by the shift lever

Hour meter does not operate

Pointers of all the gauges are deflected to their limits

One of the gauges does not indicate properly *

All the gauge pointers do not move

One of the gauge pointers does not move

Pointer of the tachometer does not move

During operation, two or more monitor lamps light improperly *

Possible cause

During operation, one of the monitor lamps lights improperly *

(1) Check the fuses. (2) Lamp test Turn the starter switch key to "ON" position and leave it there for 3 seconds. Check the indicator lamps.

Symptoms/check point

Check before starting work

Two or more monitor lamps will not light after setting the starter key to ON

1. Instrument panel does not indicate properly

One of the monitor lamps will not light after setting the starter key to ON

Electrical Group

Solution

Bulb of monitor lamp burnt out

Bulb replacement

Defective sensor or improper wiring

Sensor replacement

Disconnected or defective electrical circuit

Repairing cable

Loose connector

Connector check and re-connection

T/M controller breaker turned off

Inspection & repair

T/M controller failure alarm turned on

Inspection & repair

Defective T/M controller

Controller replacement

Defective inside mechanism of gauge or meter

Replacement

Defective board of instrument panel

Replacement

T/M solenoid valves improperly connected

Properly connect

Gauge circuit grounded improperly

Inspection & repair

* If the gauge and warning lamps do not agree there probably is a defect in the wiring. Stop immediately and diagnose

Remarks

the defect.

01-30

Clutch solenoid valve power line contact with chassis (Wire chaffed or pinched by other components, etc.) Clutch solenoid valve power line occasional contact with chassis

Breaker is turned off when a certain speed or direction is selected

Coil of the solenoid valve has extremely low resistance

Breaker is turned off if the machine sways during travelling

Possible cause

Breaker is turned off immedeately after turning on

Symptoms/check point

2. Breaker of the transmission controller is turned off

Controller failure lamp is on and will not go out

TROUBLESHOOTING 01

Both the forward and reverse shift lever position enable the engine to start

70ZV

In the solenoid valve continuity test, change the positive and negative sides to each other. After that, power is still supplied to the solenoid valve

Electrical Group

Solution Inspection & repair Inspection & repair

Clutch solenoid valve coil short circuited

Solenoid valve replacement

Clutch solenoid valve diode failed

Solenoid valve replacement

Neutral relay power line contact with chassis

Inspection & repair

Neutral relay power line occasional contact with chassis Controller failure relay power line contact with chassis Controller failure relay power line occasional contact with chassis

Inspection & repair Inspection & repair Inspection & repair

01-31

MEMO

MEASUREMENT FOR PERFORMANCE CHECK 03 Standard Measurement Values for Performance Check ............................03-2 Preparation for Performance Check ...........................................................03-6 Measuring Engine Speed ...........................................................................03-8 Oil Pressure Gauge Port with Quick Coupler ...........................................03-12 Measuring Clutch Oil Pressure and Time Lag ..........................................03-13 Measuring Cylinder Drift ...........................................................................03-16 Measuring Boom Cycle Time ....................................................................03-18 Measuring Full Steering Cycle Time .........................................................03-19 Measuring Relief Valve Setting Pressures ...............................................03-21 Measuring Fan Revolution ........................................................................03-27 Checking Brake Performance ...................................................................03-29 Measuring Brake Line Oil Pressure ..........................................................03-31 Measuring Accumulator Circuit Charging Time ........................................03-35 Measuring Number of Brake Pedal Applications ......................................03-37 Measuring Declutch Engagement .............................................................03-38

03-1

Standard Measurement Values for Performance Check

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Standard Measurement Values for Performance Check (S/N 5001~5130) Measurement conditions: Temperature of torque converter oil : 50 to 80°C (120~180°F) Temperature of hydraulic oil : 50 to 80°C (120~180°F) Temperature of engine coolant : 50 to 80°C (120~180°F)

Measurement item

Standard measurement values for performance check

Minimum no-load speed, Low Idle (LI)

775 ± 50

Maximum no-load speed, High Idle (HI)

2,600 ± 50

Maximum speed in torque converter stall mode

2,455 ± 100

Maximum speed in multiple control valve relief mode

2,450 ± 100

Maximum speed in torque converter stall plus multiple control valve relief mode

1,900 +150 - 100

Item

Transmission

Engine

System

Engine speed (min-1) (rpm)

Clutch pressure MPa (kgf/cm2) (psi) Clutch time lag (sec) Cylinder drift (when boom and bucket are horizontal and with no load) (mm/min) (in/min) Boom rising time (no load) (sec)

Hydraulic pressure

Full steering time (sec)

Relief valve setting pressure MPa (kgf/cm2) (psi)

Idling(LI)

Remarks

1.5 (15) (213) or more

Engine speed Maximum(HI)

1.8~2.1 (18~21) (256~299)

Neutral → Forward 1st speed (engine speed: 1,500 min-1 (rpm))

0.3 ± 0.1

Boom cylinder

3 (1/8) or less

Bucket cylinder

4 (5/32) or less Idling (LI)

Engine speed

Before wheels move

21 ± 3.0

1,500 min (rpm)

10 ± 1.0

Maximum (HI)

6.0 ± 0.5

Idling (LI)

5.0 ± 0.5

-1

1,500 min (rpm)

2.1 ± 0.3

Maximum (HI)

2.0 ± 0.3

-1

Loading line main relief pressure (HI)

20.6 ± 0.5 (210 ± 5) (2,986 ± 71)

Loading line overload relief pressure (LI)

23.5 ± 0.5 (240 ±5) (3,413±71)

Steering line main relief pressure (HI)

20.6 ± 0.5 (210 ± 5) (2,986 ± 71)

Steering line overload relief pressure (LI)

Fan motor line relief pressure (HI) (Reference values)

+10 24.5 +1.0 0 (250 0 ) +142 (3,555 0 )

Run engine at lowest possible speed while setting

+8 +114 Low press.: 9.1 +0.8 - 0.5 (93 - 5) (1,320 - 71 ) +0.8 +8 +114 ❈ High press.: 17.5 - 0.5 (178 - 5) (2,530 - 71 )

✽

Pilot line reducing pressure (LI)

3.5 (36) (512)

Fan Max.revolution

Engine water temp. < 94°C (200°F )

1,400 +75 - 50

✽

Low press.: 9.1 +0.8 - 0.5

min-1 (rpm)

Engine water temp. > 94°C (200°F )

2,000 +75 - 50

❈

High press.: 17.5 +0.8 - 0.5

03-2

Standard Measurement Values for Performance Check

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Item System

Measurement item

Performance of service brake

Brake

Performance of parking brake

Brake line setting pressure MPa (kgf/cm2) (psi)

Shift lever position

2nd speed reverse

Engine speed

Maximum (HI)

Shift lever position

3rd speed reverse

Remarks

Slowly increase the engine speed, and check that the machine does not move at the maximum engine speed.

Brake pedal fully depressed and held down during test.

↑

Before brake check, be sure to disconnect the cable connector of parking brake solenoid valve.

Engine speed

Maximum (HI)

Unloader valve setting pressure (LI)

Off (Cut-out)

11.8 ± 0.5 (120 ± 5) (1,706 ± 71)

On (Cut-in)

6.9 ± 1.0 (70 ± 10) (995 ± 142)

Low-pressure alarm switch setting pressure (For brake accumulator circuit)

Engine speed (LI)

3.9 ± 0.5 (40 ± 5) (569 ± 71) 12.3 (125) (1,778)

Brake line reducing pressure

Accumulator charge time (sec)

Standard measurement values for performance check

The time from the low-pressure alarm is turned off till the unloading valve cuts off pressure

Number of brake pedal applications

Run engine 1 minute high idle, then stop the engine. (Turn key switch "ON" with engine off.) Step on the brake pedal and release, and check the number of times until the low-pressure alarm is turned on.

at least 9 times

Repeat stepping on the brake pedal as follows: On: 5 sec. Off: 5 sec.

Declutch engagement (cm) (in)

Engine: Maximum speed / Inching pedal: Quick release (Distance the loader rolls back before moving forward)

15 (6) or less

1/5 slope (approx. 11°), unladen, 1st speed

03-3

Standard Measurement Values for Performance Check

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

(S/N 5131~) Measurement conditions: Temperature of torque converter oil : 50 to 80°C (120~180°F) Temperature of hydraulic oil : 50 to 80°C (120~180°F) Temperature of engine coolant : 50 to 80°C (120~180°F)

Measurement item

Standard measurement values for performance check

Minimum no-load speed, Low Idle (LI)

775 ± 50

Maximum no-load speed, High Idle (HI)

2,600 ± 50

Maximum speed in torque converter stall mode

2,455 ± 100

Maximum speed in multiple control valve relief mode

2,450 ± 100

Maximum speed in torque converter stall plus multiple control valve relief mode

1,900 +150 - 100

Item

Transmission

Engine

System

Engine speed (min-1) (rpm)

Clutch pressure MPa (kgf/cm2) (psi) Clutch time lag (sec) Cylinder drift (when boom and bucket are horizontal and with no load) (mm/min) (in/min) Boom rising time (no load) (sec)

Hydraulic pressure

Full steering time (sec)

Relief valve setting pressure MPa (kgf/cm2) (psi)

Idling(LI)

Remarks

1.5 (15) (213) or more

Engine speed Maximum(HI)

1.8~2.1 (18~21) (256~299)

Neutral → Forward 1st speed (engine speed: 1,500 min-1 (rpm))

0.3 ± 0.1

Boom cylinder

3 (1/8) or less

Bucket cylinder

4 (5/32) or less Idling (LI)

Engine speed

Before wheels move

21 ± 3.0

1,500 min (rpm)

10 ± 1.0

Maximum (HI)

6.0 ± 0.5

Idling (LI)

5.0 ± 0.5

-1

1,500 min (rpm)

2.1 ± 0.3

Maximum (HI)

2.0 ± 0.3

-1

Loading line main relief pressure (HI)

20.6 ± 0.5 (210 ± 5) (2,986 ± 71)

Loading line overload relief pressure (LI)

23.5 ± 0.5 (240 ±5) (3,413±71)

Steering line main relief pressure (HI)

20.6 ± 0.5 (210 ± 5) (2,986 ± 71)

Steering line overload relief pressure (LI)

Fan motor line relief pressure (HI) (Reference values)

+10 24.5 +1.0 0 (250 0 ) +142 (3,555 0 )

Run engine at lowest possible speed while setting

+8 +114 Low press.: 7.4 +0.8 - 0.5 (75 - 5) (1,075 - 71 ) +0.8 +8 +114 ❈ High press.: 14.7 - 0.5 (150 - 5) (2,130 - 71 )

✽

Pilot line reducing pressure (LI)

3.5 (36) (512)

Fan Max.revolution

Engine water temp. < 80°C (176°F )

1,400 +75 - 50

✽

Low press.: 7.4 MPa

min-1 (rpm)

Engine water temp. > 93°C (200°F )

+75 - 50

❈

High press.: 14.7 MPa

2,000

03-4

Standard Measurement Values for Performance Check

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Item System

Measurement item

Performance of service brake

Brake

Performance of parking brake

Brake line setting pressure MPa (kgf/cm2) (psi)

Shift lever position

2nd speed reverse

Engine speed

Maximum (HI)

Shift lever position

3rd speed reverse

Remarks

Slowly increase the engine speed, and check that the machine does not move at the maximum engine speed.

Brake pedal fully depressed and held down during test.

↑

Before brake check, be sure to disconnect the cable connector of parking brake solenoid valve.

Engine speed

Maximum (HI)

Unloader valve setting pressure (LI)

Off (Cut-out)

11.8 ± 0.5 (120 ± 5) (1,706 ± 71)

On (Cut-in)

6.9 ± 1.0 (70 ± 10) (995 ± 142)

Low-pressure alarm switch setting pressure (For brake accumulator circuit)

Engine speed (LI)

3.9 ± 0.5 (40 ± 5) (569 ± 71) 12.3 (125) (1,778)

Brake line reducing pressure

Accumulator charge time (sec)

Standard measurement values for performance check

The time from the low-pressure alarm is turned off till the unloading valve cuts off pressure

Number of brake pedal applications

at least 9 times

Repeat stepping on the brake pedal as follows: On: 5 sec. Off: 5 sec.

Declutch engagement (cm) (in)

Engine: Maximum speed / Inching pedal: Quick release (Distance the loader rolls back before moving forward)

15 (6) or less

1/5 slope (approx. 11°), unladen, 1st speed

03-5

Preparation for Performance Check

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Preparation for Performance Check WARNING

CAUTION

Unexpected movement of the machine may cause an accident resulting in injury or death. Therefore, to provide repair service with the engine running, be sure to observe the following items: - Park the machine on level ground. - Apply the parking brake. - Block the tires with chocks to prevent the tires from moving. - Determine the signals between the service men. - Prohibit any person from walking into dangerous areas. - Near articulation area of the machine - Under the machine - Around the engine - In front of or behind the machine

Do not touch the fan or V-belt of the engine or a hig-temperature section if the engine is running. An accident resulting in injury may occur. Be sure to stop the engine before you open the side cover of the engine room. Keep all guards in place. Avoid high temperature components even when the engine is stopped.

Preparation of measurement units - To measure pressure, be sure to prepare the hose, adapter, and wrench for pressure port plug in addition to the measurement instruments.

Cautions regarding measurement - Take safety precautions before starting measurement work, and carefully measure and record the valves. - Measure a value three times or more. If the obtained values greatly differs from each other, an error has been made in measuring the value. Measure the value again. Calculate the average value from the various readings.

- Check operation of the measurement instruments. Carefully handle the instruments. If something comes in contact with an instrument or large shock is applied to an instrument, the instrument may be damaged. In addition, periodic inspection of the instruments is also important. If the zero point of an instruments is not properly adjusted, the value indicated by the instrument may be wrong.

Warm-up - If the machine is too cold, measured values may be wrong. To prevent incorrect readings, be sure to warm up the machine until the torque converter oil, hydraulic oil, and engine coolant are heated to the specified temperature.

03-6

Preparation for Performance Check

70ZV

Procedure for warm-up 1) Torque converter oil temperature Perform torque converter stall operation by referring to "Stall speed measurement procedure". Check the approximate temperature using the temperature gauge in the instrument panel. 2) Hydraulic oil temperature Perform multiple control valve relief operation by referring to "Engine speed measurement procedure in multiple control valve relief mode". Check the approximate temperature using the contact thermometer attached to the outside surface of the hydraulic tank.

MEASUREMENT FOR PERFORMANCE CHECK 03

(140°F) (176°F) (212°F) (230°F) 60°C 80°C 100°C 110°C

T/C OIL TEMP

Torque converter oil temperature gauge

(140°F) (176°F) (194°F) (230°F) 60°C 80°C 100°C 110°C

3) Engine coolant temperature Warming up the torque converter oil and hydraulic oil also warms up the engine. Check the engine coolant temperature using the temperature gauge in the instrument panel.

03-7

WATER TEMP

Engine coolant temperature gauge 65ZV03004

Measuring Engine Speed

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Measuring Engine Speed WARNING

CAUTION

Do not touch the fan or V-belt of the engine or a high-temperature section if the engine is running. An accident resulting in injury may occur. Be sure to stop the engine before you open the side cover of the engine room. Keep all guards in place. Avoid high temperature components even after the engine is stopped.

Measurement instrument - Tachometer drive port Note : A tachometer is already provided on the instrument panel. Warm - up the engine before measuring the engine speed Standard measurement value (min-1) (rpm) Minimum no-load speed (LI)

775 ± 50

Minimum no-load speed (HI)

2,600 ± 50

Maximum speed in torque converter stall mode

2,455 ± 100

Maximum speed in multiple control valve relief mode

2,450 ± 100

Maximum speed in torque converter stall plus multiple control valve relief mode (Full stall)

1,900 ± 150 100

03-8

Measuring Engine Speed

70ZV

Stall speed measurement procedure

MEASUREMENT FOR PERFORMANCE CHECK 03

Engine speed measurement procedure in multiple control valve relief mode

WARNING

IMPORTANT

Unexpected movement of the machine for abnormal brake performance may cause an accident resulting in injury or death. Before measuring, make sure that the machine has sufficient brake performance.

When the relief valve is activated, the oil temperature rises rapidly. Therefore, long relief operation may damage the seals or cause the spool to stick inside the valve. This is why relief operation should be limited to 10 seconds. To repeat the relief operation, be sure to wait more than 10 seconds with medium engine speed before next relief operation, and cool the inside of the valve. Using this cycle safely warms up cold oil.

IMPORTANT In the stall mode, the torque converter oil temperature rises rapidly. Therefore, long stall operation may damage the seals, and the damaged seal may cause oil leakage. This is why stall test should be limited to 20 seconds. The torque converter oil temperature should not be exceeded 120°C (250°F). To repeat the stall operation, be sure to wait more than 10 seconds with medium engine speed before next stall operation so that the torque converter oil is cooled enough.

1) Lower the boom to the lowest limit. Roll back the bucket fully until the bucket contacts to the stopper. 2) Set the parking brake to the "ON" position. 3) Set the engine speed to HI. 4) Place the bucket control lever in roll back position. Measure the engine speed.

1) Lower the boom to the lowest limit. Roll back the bucket fully until the bucket contacts to the stopper. 2) Set the parking brake to the "OFF" position. 3) Set the clutch cut off switch to OFF. 4) Press the brake pedal all the way to the floor, and then set the transmission shift lever to the maximum forward speed position ("4"). Note : Cancel the auto shift mode. (Refer to Section 62 Transmission Control Circuit.) As a result the transmission shift lever "A" position works as "4" position. 5) Gradually increase the engine speed. Measure the engine speed when the accelerator pedal is fully pressed down. 6) Record the engine speed at T/C stall. (During stall speed measurement, do not operate the steering system, boom, bucket, etc.)

03-9

97ZV03002

Measuring Engine Speed

70ZV

Full stall procedure

IMPORTANT In the stall mode, the torque converter oil temperature and the hydraulic oil temperature rise rapidly. Therefore, long stall operation may damage the seals, and the damaged seal may cause oil leakage. This is why stall test should be limited to 10 seconds. The torque converter oil temperature should not be exceeded 120°C (250°F). To repeat the stall operation, be sure to wait more than 10 seconds with medium engine speed before next stall operation, and cool the torque converter oil and the inside of the valve. Using this cycle safely warms up cold oil.

1) Lower the boom to the lowest limit. Roll back the bucket fully until the bucket contacts to the stopper. 2) Set the parking brake to the "OFF" position. 3) Set the clutch cut off switch to OFF. 4) Press the brake pedal all the way to the floor, and then set the transmission shift lever to the maximum forward speed position ("4"). Note : Cancel the auto shift mode. (Refer to Section 62 Transmission Control Circuit.) As a result the transmission shift lever "A" position works as "4" position. 5) Gradually increase the engine speed. 6) Place the bucket control lever in roll back position. 7) Measure the engine speed when the accelerator pedal is fully pressed down.

03-10

MEASUREMENT FOR PERFORMANCE CHECK 03

Measuring Engine Speed

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Cause of extremely high or low measurement value and solution Minimum no-load speed(LI) or maximum no-load speed(HI) low

Possible cause Insufficient warm up Malfunctioning accelerator pedal

Solution

Possible cause

Warm up

Relief valve pressure too low

Adjustment or disassembly

Defective hydraulic pump / pump seals

Disassembly & repair

Inspection & repair

Clogged fuel filter

Clean

Defective fuel pump

Repair

Defective fuel injection nozzle

Repair

Valve clearances incorrect Insufficient compression pressure

The engine speed is too high in multiple control valve relief mode.

The engine speed is too low in multiple control valve relief mode.

Adjustment Possible cause

Repair

The engine speed is too high in torque converter stall mode.

Possible cause

Solution

Slipping transmission clutch or defect inside of transmission

Disassembly & repair

Defect inside torque converter

Disassembly & repair

Solution

Engine low power

Inspection & repair

Extremely high relief pressure of multiple control valve

Adjustment

The engine speed is too high in torque converter stall plus multiple control valve relief mode. (Full stall)

The engine speed is too low in torque converter stall mode.

Possible cause

Solution

Slipping transmission clutch or defect inside of transmission or T/C

Disassembly & repair

Relief pressure too low

Adjustment

Defective pump / pump seals

Disassembly & repair

Caused by reduction in engine power Possible cause Clogged air cleaner element Improper type of fuel Clogged fuel filter or suction strainer Frozen fuel / wax build up Malfunctioning accelerator pedal

The engine speed is too low in torque converter stall plus multiple control valve relief mode. (Full stall)

Solution Cleaning Fuel replacement

Possible cause

Clean or replace Use antifreeze mixture Inspection & repair

Defective fuel pump

Repair

Defective fuel injector nozzle

Repair

Insufficient compression pressure

Repair

03-11

Solution

Engine low power

Inspection & repair

Extremely high relief pressure of multiple control valve or steering valve

Adjustment

Oil Pressure Gauge Port with Quick Coupler

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Oil Pressure Gauge Port with Quick Coupler (For USA Spec.)

2 3

70ZV03001

1. T/M clutch oil pressure 2. Hydraulic line oil pressure 3. Steering line oil pressure 4. Pilot line reducing oil pressure

03-12

Measuring Clutch Oil Pressure and Time Lag

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Measuring Clutch Oil Pressure and Time Lag WARNING Unexpected movement of the machine may cause an accident resulting in injury or death. Therefore, to provide repair service with the engine running, be sure to observe the following items: - Park the machine on level ground. - Apply the parking brake. - Block the tires with chocks to prevent the tires from moving. - Determine the signals between the service men. - Prohibit any person from walking into dangerous areas. - Near articulation area of the machine - Under the machine - Around the engine - In front of or behind the machine

- Standard measurement value

Clutch pressure MPa (kgf/cm2) (psi)

Clutch time lag (sec)

Measurement instruments: - Pressure gauge: 2.9 MPa (30 kgf/cm2) (500 psi)

Low idle

1.5 (15) (213) or more

High idle

1.8 ~ 2.1 (18 ~ 21) (256 ~ 299)

Neutral1st forward speed (engine speed: 1,500 min-1 (rpm))

0.3 ± 0.1

Engine speed

with 2 ~ 3 m (6 ~ 10 ft.) hose Pressure measurement port: PF1/4 with O-ring - Tachometer - Stop watch Warm-up the engine before measuring the clutch oil pressure and time lag Clutch oil pressure measurement procedure 1) Lower the boom to the lowest limit, and lower the attachment onto the ground. 2) Set the parking brake to the "ON" position. 3) Set the transmission shift lever to the neutral position. 4) Stop the engine. Attach the pressure gauge to the pressure measurement port. Place the gauge inside the operator's area, start the engine. 5) As the clutch oil pressure rises just after the engine is started, adjust the engine to the specified speed before the pressure measurement. 6) Measure and record the pressure in each speed range. 7) Change the transmission speed range while keeping the shift lever at the neutral position. Check that the pressure instantaneously lowers just after speed change, and then rises to the original pressure again.

03-13

70ZV03001J

Clutch oil pressure test port location

Measuring Clutch Oil Pressure and Time Lag

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

4th speed clutch oil pressure (PF1/4) 1st speed clutch oil pressure (PF1/4) 2nd speed clutch oil pressure (PF1/4) B

View from A

3rd speed clutch oil pressure (PF1/4)

Forward clutch oil pressure (PF1/4)

Main oil pressure (PF1/4)

Reverse clutch oil pressure (PF1/4)

View from B

70ZV03002

Clutch oil pressure measurement port location

03-14

Measuring Clutch Oil Pressure and Time Lag

70ZV

Time lag measurement procedure: 1) Lower the boom to the lowest limit, and fully roll back the attachment until the attachment contacts to the stopper. 2) Set the parking brake switch to the "OFF" position. Do not apply the service brakes. 3) Set the transmission shift lever to the neutral 1st speed. 4) Keep the engine speed at 1,500 min-1 (rpm). 5) Move the shift lever to the forward position. At the same time, start the stop watch to measure the time required before the machine moves. Possible causes for low clutch oil pressure and clutch time lag Clutch oil pressure too low

Possible cause

Solution

• Pressure is too low in all speed ranges and both directions • Defective clutch oil regulator valve • Defective torque converter charge pump

Disassembly & repair

• Pressure is too low in one speed range or direction • Oil leakage between control valve and clutch • Clutch piston seal • Rotating seal rings

Inspection & repair

Clutch time lag

Possible cause

Solution

• Pressure is too low in all speed ranges and both directions • Defective torque converter pump • Defective main accumulator

Replacement

• Defective main pressure sensing valve

Disassembly & repair

• Pressure is too low in one speed range or direction • Oil leakage between control valve and clutch

Inspection & repair

• Defective solenoid valve

Replacement

• Defective speed selector spool

Disassembly & repair

• 1st or 2nd speed accumulator defective

Disassembly & repair

03-15

MEASUREMENT FOR PERFORMANCE CHECK 03

WARNING Unexpected movement of the machine may cause an accident resulting in injury or death. To crawl under the machine, be sure to stop the engine, and block the tires with chocks to prevent them from moving. Give signals to the person in the cab during the work.

Measuring Cylinder Drift

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Measuring Cylinder Drift WARNING Standing under the boom or bucket during service work is dangerous. An accident resulting in injury or death may be caused. To prevent such an accident, be sure to lock the boom and bucket control levers in the cab, securely support the boom, and remove the starter key. In addition, hang a "DO NOT OPERATE!" tag on the steering wheel.

Measurement instrument - Scale : 150 to 300 mm (1 ft.) - Stop watch - Black vinyl "electrician's" tape Warm-up the hydraulic oil before measuring cylinder drift

Reference : Drift rate depends on the viscosity of the hydraulic oil and its temperature. In other words, high temperature of the hydraulic oil reduces the viscosity. Reduction in oil viscosity increases oil leakage through the seals, and increases the drift rate. Cold thick oil reduces the drift rate.

Standard measurement value (mm/min)(in/min) Boom cylinder

3 (1/8) or less

Bucket cylinder

4 (5/32) or less

Measurement procedure 1) Unload the bucket or forks. 2) Keep the boom and bucket horizontal. 3) Set the parking brake switch to the "ON" position. 4) Lock the boom and bucket control levers using the safety lock. 5) Stop the engine. 6) Mark the cylinder rod at a point 100 to 150 mm (4~6 in) away from the cylinder head cover. 7) Measure the accurate distance from the cylinder head cover to the mark. This is distance "A" mm (in). Measure the distance again 5 minutes later. This is distance "B" mm (in). Cylinder drift (mm/min) = A – B (mm) (in) 5 (min) (in/min) 8) Immediately remove the tape from the cylinder rod. 03-16

Mark Scale

85ZV03002

IMPORTANT At the completion of measurement, if the vinyl tape used for measurement is not removed from the cylinder rod, the tape may be caught by the rod seal. The tape will cause oil leakage from the rod seal. To prevent oil leakage, be sure to remove the vinyl tape.

Measuring Cylinder Drift

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Possible causes of excessive cylinder drift: Bucket cylinder Possible cause

Solution

Damaged cylinder piston seal / barrel

Disassembly & repair

Defective multiple control valve overload relief valve

Disassembly & repair

Oil leakage from multiple control valve bucket spool

Disassembly & repair

- Identifying defective part Pressure is applied to the bucket cylinder bottom side to support the bucket. There should be no pressure applied to the cylinder rod side.

Bucket cylinder

Keep the boom and bucket horizontal, and stop the engine. Carefully loosen the split flange (see the arrow) on the cylinder rod side. If the compressed oil spouts from the cylinder, judge that the piston seal and/or cylinder barrel is damaged. If the compressed oil spouts from the hose side, judge that the piston seal of the other cylinder is defective. (65TMV/ 90ZV/95ZV/115ZV) If no compressed oil spouts from the cylinder, judge that the cause is the defective multiple control overload relief valve or oil leakage from the main spool of multiple control valve. Note : If only a few drops come out per minute it is considered normal.

70ZV03003

Bucket cylinder rod side flange

Boom cylinder Possible cause

Solution

Damaged cylinder piston seal / barrel

Disassembly & repair

Oil leakage from multiple control valve boom spool

Disassembly & repair

- Identifying defective part Just like the bucket cylinder, no pressure should be applied to the rod side of the boom cylinder when the weight of the boom is resting on the boom cylinders. Carefully loosen the split flange (see the arrow) for the pipe on the cylinder rod side. If the compressed oil spouts from the cylinder, judge that the piston seal and/or barrel of the boom cylinder is damaged. If the compressed oil spouts from the pipe side, judge that the piston seal of the other cylinder is defective. It is possible both cylinders are defective.

Boom cylinder

70ZV03004

Boom cylinder rod side flange If no oil spouts from the split flange, judge that oil is leaking from the multiple control valve spool.

03-17

Measuring Boom Cycle Time

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Measuring Boom Cycle Time Possible causes of slow boom cycle time:

WARNING

Possible cause

Standing under the boom or bucket during service work is dangerous. An accident resulting in injury or death may occur. Stay out of the area around the raised boom.

Damaged main pump / seals Damaged steering pump / seals Multiple control valve spool sticking

Measuring instrument - Stop watch - Tachometer (if required) Warm-up the engine and hydraulic system before measuring boom rising time Standard measurement value

Engine speed

How to determine the cause (damaged main pump or steering pump): Measure the full steering time. If normal the main pump is damaged or the mcv spool is sticking. If steering time is also slow the steering pump is damaged. Boom cylinder

(Seconds)

21 ± 3.0

Idling (LI) 1,500 min (RPM)

10 ± 1.0

Maximum (HI)

6.0 ± 0.5

-1

Solution Disassembly & repair Disassembly & repair Disassembly & repair

To steering line Steering valve

Measurement procedure 1) Unload the bucket or forks. 2) Lower the boom to the lower limit, and roll back the bucket. 3) Set the parking brake switch to the "ON" position. Stop the engine and install the tachometer. 4) Adjust the engine speed to the specified point. 5) Measure the time required for raising the boom from the lowest limit to the highest limit. Note : Even if the boom kick out system (optional) is installed, the boom control lever should be held in the UP position until the boom rises to the highest limit.

97ZV03005

03-18

Multiple control valve Steering pump

Main pump

Hydraulic oil tank 95ZV03004

Measuring Full Steering Cycle Time

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Measuring Full Steering Cycle Time WARNING Standing in the articulation area during service work is dangerous. An accident resulting in injury or death may occur. During this test, prevent any person from walking around the machine or in the articulation area. Measuring instrument - Stop watch - Tachometer (if required)

97ZV03007

Full steering

Warm-up the engine and hydraulic system before measuring full steering time Standard measurement value

2.1 ± 0.3

Maximum (HI)

2.0 ± 0.3

Measurement procedure 1) Adjust the stopper bolts of the front chassis so that the front chassis stopper contacts to the rear chassis in both directions. 2) Unload the bucket. 3) Lower the boom to the lower limit, and roll back the bucket. 4) Set the parking brake switch to the "OFF" position and release the brake pedal. 5) Adjust the engine speed to the specified point. 6) Measure and record the time required for full steering. - From full left to full right or - From full right to full left Turn the steering wheel as fast as possible during the test. Note : The machine must be on level ground. Using a hard surface, like concrete or asphalt is best. Soft surfaces can create drag and increase steering time.

IMPORTANT After measuring, return the stopper bolts. (Refer to "Stop Valve" in Check & Adjustment.) 03-19

Front chassis Reference dimension 33.8~38.7 mm (1.33~1.52 in) Stopper (bolt) length

70ZV44018

Front chassis

38°

1,500 min (RPM) -1

36°~

Engine speed

Stopper (bolt)

5.0 ± 0.5

Idling (LI)

Stop valve (rear chassis) (L.H, R.H)

(Seconds)

Rear chassis Reference dimension 8.3~16.6 mm (0.33~0.54 in) Clearance between machine body and stopper 85ZVE43003

Measuring Full Steering Cycle Time

70ZV

Possible causes for slow steering times: Possible cause

Solution

Damaged steering pump / seals

Disassembly & repair

Malfunctioning steering valve flow control plunger or steering spool

Disassembly & repair

Flow control plunger

P Pc

Steering valve

90ZV03005

03-20

MEASUREMENT FOR PERFORMANCE CHECK 03

Measuring Relief Valve Setting Pressures

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Measuring Relief Valve Setting Pressures WARNING

CAUTION

Unexpected movement of the machine may cause an accident resulting in injury or death. Therefore, to provide repair service with the engine running, be sure to observe the following items : - Park the machine on level ground. - Apply the parking brake. - Block the tires with chocks to prevent the tires from moving. - Determine the signals between the service man. - Prohibit any person from walking into dangerous areas. - Near articulation areas of the machine - Under the machine - Around the engine - In front of or behind the machine

2. Standard measurement value MPa (kgf/cm2) (psi)

CAUTION Be careful, you may get burned if the high pressure oil spouts out. To prevent such an accident, be sure to release the residual pressure from the pipe, and open the cap of the hydraulic oil tank before removing the plug and hose from the pressure measurement port.

Loading line main relief pressure (at maximum speed)

20.6 ± 0.5 (210 ± 5) (2,986 ± 71)

Loading line overload relief pressure (at idling speed)

23.5 ± 0.5 (240 ± 5) (3,413 ± 71)

Steering line main relief pressure (at maximum speed)

20.6 ± 0.5 (210 ± 5) (2,986 ± 71)

Steering line overload relief pressure (at idling speed)

24.5 +1.0 0 +142 (250 +10 0 ) (3,555 0 )

Pilot line reducing valve pressure (at idling speed)

3.5 (36) (512)

Hydraulic oil temp : 50~80 °C (120~180 °F)

1. Measurement instruments : Pressure gauge 34.3 MPa (350 kgf/cm2) (5,000 psi) (for loading and steering lines) with 1.5~3 m (4~10 ft.) hose 4.9 MPa (50 kgf/cm2) (1,000 psi) (for pilot line) with 2~3 m (6~10 ft.) hose Note : For safety, route the gauge to an area where it may be safely read by the person doing the test. North American machines can be tested using pressure gauge kit available from the Kawasaki dealer.

Releasing residual pressure from tank and pipes. Keep the bottom surface of the bucket horizontal, and stop the engine when the bucket is approximately 30 cm (1 ft.) above the ground. Tilt down the bucket until it comes in contact with the ground. Place the bucket control lever in the roll back position, and then lower the boom. Push down on, then open the cap of the hydraulic oil tank to release the residual pressure. Use the same procedure for other types of attachments.

03-21

Measuring Relief Valve Setting Pressures

70ZV

Loading Circuit

MEASUREMENT FOR PERFORMANCE CHECK 03

Bucket cylinder

1. Gauge port and port size Gauge port location Main relief pressure Overload relief pressure

➀, ➁, ➂ ➀, ➁, ➂

Port size

➀…Rc (PT) 1/4 , ➁ ……➂

G (PF) 1/4 with O-ring Note: North America equipped M/c's have a quick connector in port 3 for testing.

➃…G (PF) 3/8 Pilot line pressure (Reducing valve)

➃, ➄

with O-ring

➄…G (PF) 1/4

70ZV43001

with O-ring

Multiple control valve Warm up the hydraulic system before testing.

Main relief valve

2. Measuring loading line main relief pressure 1) Unload the bucket or forks. 2) Lower the boom to the lowest limit. 3) Attach the pressure gauge 29.4 MPa (5,000 psi) to the quick connector port (➂). 4) Set the parking brake switch to the "ON" position. 5) Move the bucket control lever to the roll back position. Hold the lever at that position. 6) Increase the engine speed to the maximum, and measure and record the pressure using the pressure gauge.

Overload relief valve

Overload relief valve 70ZV43002

Valve assembly 5 (Z)

(PPI)

(Z2)

(Z1)

(PA) ACF (PARKING) (TA)

Adjusting main relief pressure : Loosen the lock nut and adjust the pressure by the adjusting screw. Turn the adjusting screw clockwise to raise the set pressure, or turn the adjusting screw counterclockwise to lower the set pressure.

IMPORTANT

TOP

(T)

(ACCF)

(ACCR) (PI)

(P)

Reducing valve (for pilot) 70ZV43003

Main relief valve Adjusting screw

At the completion of check and adjustment of main relief valve pressure, be sure to tighten the lock nut. Recheck the pressure setting to confirm the adjustment.

Lock nut 70ZV43004

03-22

Measuring Relief Valve Setting Pressures

70ZV

3. Measuring loading line overload relief pressure Note : Perform this test only when there is a problem with cylinder drift. Do not preform this procedure as a routine test. 1) Attach the pressure gauge to the port ➂ 2) Adjust the main relief valve pressure to 24.5 MPa (3,555 psi) + 1/4 additional turn, so the pressure is above the overload relief pressure. Bucket cylinder bottom side : (1) Lower the boom to the lowest limit. (2) Move the bucket control lever to the roll back position. (3) Keep the engine speed at low idle. (4) Hold the bucket control lever at the roll back position and record the pressure. Bucket cylinder rod side : (1) Keep the boom horizontal. (2) Move the bucket control lever to the dump position, hold and then measure and record the pressure. Adjusting overload relief pressure : Loosen the lock nut and adjust the pressure by the adjusting screw. Turn clockwise the adjusting screw to raise the set pressure, or turn counterclockwise the adjusting screw to lower the set pressure.

MEASUREMENT FOR PERFORMANCE CHECK 03

4. Measuring pilot line pressure

WARNING Trapped pressure in brake circuit could cause serious injury when the plug is removed. Fully release all residual accumulator pressure before servicing. Depress and release the brake pedal 80~100 times to discharge the oil pressure. 1) Attach the pressure gauge to the port (➃ or ➄). 2) Keep the engine speed at low idle (when the brake line pressure is normal) and then measure and record the pressure. Adjusting pilot line pressure : Loosen the lock nut and adjust the pressure by the adjusting screw. Turn clockwise the adjusting screw to raise the pilot line pressure.

IMPORTANT After the completion of the adjustment of the pilot line pressure, be sure to tighten the lock nut.

Reducing valve

IMPORTANT

Lock nut

At the completion of check and adjustment of overload relief valve pressure, be sure to reset the main relief valve to the original condition.

Adjusting screw 70ZV43006

Overload relief valve

Lock nut

Adjusting screw 70ZV43005

03-23

Measuring Relief Valve Setting Pressures

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Steering Circuit

Steering cylinder

1. Gauge port and port size Gauge port location

Port size

➀, ➁

G (PF) 1/4 with O-ring

Main relief pressure Overload relief pressure Reducing pressure

➂

Note: North America equipped 1 M/c's have quick connectors at ports 1 and 2 .

Rc (PT 1/8)

70ZV43007

Warm up the hydraulic system before testing. Reducing valve

2. Measuring steering line main relief pressure 1) Attach the pressure gauge to the gauge port (➀ or ➁). 2) In case the pressure gauge is installed to ➀, steer the machine to the left until the front and rear chassis contact each other. Continue to turn the steering wheel at a steady speed of rotation. Note : Because the stop valve is installed into the steering line, oil pressure does not reach the set point when the steering is fully turned. When measuring oil pressure, be sure to apply the articulation stopper or screw the stopper (bolt) in until the front and rear chassis contact each other.

(A)

115ZV43006

(B)

Steering valve Overload relief valve

WARNING If the machine begins to move with the articulation stopper applied, it may cause an accident resulting in injury or death. After the measurement, be sure to disconnect and store the articulation stopper.

Main relief valve

70ZV43008

Main relief valve Lock nut

3) Increase the engine speed to high idle, and measure and record the pressure. Adjusting steering line main pressure : Loosen the lock nut and adjust the pressure by the adjusting screw. Turn clockwise the adjusting screw to raise the steering line main pressure. 03-24

Adjusting screw

Steering valve

70ZV43009

Measuring Relief Valve Setting Pressures

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

3. Measuring steering line overload relief pressure 1) Attach the pressure gauge to the port (➀ for the left turn, ➁ for the right turn). 2) Adjust the main relief valve pressure to 25.5 MPa (260 kgf/cm2) (3,697 psi) + 1/4 additional turn, so the pressure is above the overload relief pressure. 3) Steer the machine until the front and rear chassis contact each other. Continue to turn the steering wheel at a steady speed of rotation. Note : Because the stop valve is installed into the steering line, oil pressure does not reach the set point when the steering is fully turned. When measuring oil pressure, be sure to apply the articulation stopper or screw the stopper (bolt) in until the front and rear chassis contact each other. 4) Keep the engine speed at low idle, and measure and record the pressure. Raise the engine speed to 1,000 min-1 if the engine

Stopper (bolt)

Port B To steering valve

Port A From Orbitrol ®

Spool

Bolt Installed on front chassis

Check valve Installed on rear chassis 70ZV42049

will not maintain low idle speed. Adjusting overload relief pressure : Loosen the lock nut and adjust the pressure by the adjusting screw. Turn clockwise the adjusting screw to raise the set pressure, or turn counterclockwise the adjusting screw to lower the set pressure.

Overload relief valve Lock nut

Adjusting screw 70ZV43005

IMPORTANT

IMPORTANT After measuring, return the stopper bolts. (Refer to "Stop Valve" in Check & Adjustment.)

At the completion of check and adjustment of overload relief valve pressure, be sure to reset the main relief valve to the original condition.

03-25

Measuring Relief Valve Setting Pressures

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

4. Measuring pilot circuit relief pressure (Reducing pressure)

Adjusting screw Lock nut

1) Attach the pressure gauge to the port (➂). Gauge port plug width across flat : 5 mm 2) Move the bucket control lever to the roll back position. 3) Keep the engine speed at low idle. 4) Hold the bucket control lever at the roll back position and record the pressure. Adjusting pilot line pressure : Loosen the lock nut and adjust the pressure by the adjusting screw. Turn clockwise the adjusting screw to raise the pilot line pressure.

(T)

(A)

3 (TS)

(B)

IMPORTANT After the completion of the adjustment of the pilot line pressure, be sure to tighten the lock nut.

03-26

115ZV43007

Measuring Fan Revolution

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Measuring Fan Revolution (S/N 5001~5130)

Fan revolution adjustment procedure WARNING P1

Trapped hydraulic pressure in the hydraulic line could cause serious injury when the plug is removed. Observe the following items: - Park the machine on level ground, and apply the parking brake. In addition, block the tires with chocks to prevent wheels from moving. - Relieve the internal pressure from the hydraulic tank and the hydraulic line to prevent the oil from spouting out. - Remove the engine key, and hang a "DO NOT START ENGINE!" tag on steering wheel.

21 22 PX

PG P2

23 24

Solenoid valve

95ZV42065

Note: Whenever the fan max. revolution is adjusted, always adjust the high revolution first, because when the high revolution is changed, the low revolution is also changed. Measurement instrument: - Spanner: 22, 27, 32 mm (0.87, 1.06, 1.26 in) - Pressure gauge: 29.4 MPa (5,000 psi gauge will work) [Gauge port: PG port (PF1/4)] - Tachometer (Photo tachometer)

1. High revolution (High pressure) adjustment

2. Low revolution (Low pressure) adjustment

1) Remove the solenoid valve connection wire. When the solenoid valve is OFF, the high revolution can be adjusted. 2) Loosen the lock nut (21), adjust the rpm's (pressure) by turning the adjusting screw (22). Turn the adjusting screw clockwise as viewed from the valve end to raise the rpm's (pressure). Note: Do not raise the pressure more than 18.6 MPa (2,702 psi) during adjustment. Set revolution 2,000 min-1 (rpm) [Set pressure 17.5 MPa (179 kgf/cm2) (2,540 psi)] 3) After adjusting the fan rpm's, tighten the lock nut (21) while holding adjusting screw (22) so as not to turn it at the same time. : Lock nut 45.1 N-m (33.3 lb-ft)

1) Confirm the radiator cooling water temperature is lower than 80 °C (176 °F), and then adjust the rpm's keeping the solenoid valve connection wire installed on the relief block. When the radiator cooling water temperature is low, the solenoid valve is ON. 2) Loosen the lock nut (23), adjust the rpm's (pressure) by turning the adjusting screw (24). Turn the adjustment screw clockwise as viewed from the valve end to raise the rpm's (pressure). Set revolution 1,400 min-1 (rpm) [Set pressure 9.1 MPa (93 kgf/cm2) (1,320 psi)] 3) After adjusting the fan rpm's, tighten the lock nut (23) while holding the adjusting screw (24) so as not to turn it at the same time. : Lock nut 31.4 N-m (23.2 lb-ft)

03-27

Measuring Fan Revolution

70ZV

(S/N 5131~)

MEASUREMENT FOR PERFORMANCE CHECK 03

Fan motor (71)

Cooling fan

WARNING

23.0 cm3/rev

The residual oil pressure in the hydraulic line could spout high pressure oil and cause serious injury such as burn when a hose or plug is removed. Press the hydraulic tank cap downward to release the residual pressure from the line and the internal pressure from the tank before starting adjustment.

Check valve (73)

P1 Ps

T 14.7MPa(2,132psi)

Thermo-sensing valve (74)

Radiator

T2 Ts

P High : 14.9MPa(2,160psi)

From unloader valve

Low : 6.7MPa( 972psi)

Measuring and adjusting the maximum number of revolutions 1) Remove hose and adapter from the port Pp, and plug port Pp. Port size … PF 1/4 2) Remove the plug from the port Ps, and attach a gauge. Gauge … About 19.6 MPa (200 kgf/cm2) (3,000 psi) Port size … PF 1/4 3) Measure the number of fan revolutions while the engine is at high idle. Set pressure Engine at high idle Number of fan revolution Relief set pressure (guideline)

High Low

Relief valve (72)

Hydraulic circuit diagram

T Relief valve Adapter

Adapter Pp

2,000

min-1 (rpm)

1,400

+75 –50

min (rpm)

Plug

Ts P1

2,600 min-1 (rpm) +75 –50

70ZV42063

Plug

-1

High

14.7 MPa (150 kgf/cm2) (2,130 psi)

Low

7.4 MPa (75 kgf/cm2) (1,075 psi)

4) If the maximum number of revolutions is not correct, adjust it using the adjusting screw in the relief valve. Turn the adjusting screw clockwise to increase both the pressure and the number of fan revolution Note : - The relief valve on the low pressure side cannot be adjusted because it accommodates a thermo-sensing valve. It can be only confirmed. - After placing hose and adapter in the port Pp to normal, measure the pressure while the fan is moving at low speed. At this time, the engine cooling water temperature should be 80 °C (176 °F) or less (Engine at HI). 03-28

P 70ZV03005

Adjusting screw

Lock nut

Relief valve

65ZV43007

Checking Brake Performance

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Checking Brake Performance Service brake performance check 1) Method 1

2) Method 2 If no test course available as described "Method 1", carry out the following method.

WARNING Separate the test course by using rope etc. and keep persons away from the test course. In addition, post persons in several positions near the course to warn others and avoid an accident while checking the service brake performance.

IMPORTANT

- Condition (1) Test course Level, straight, dry and the paved ground. (2) Bucket empty (3) Run the machine and depress the brake pedal at 35 km/h (22 mph). Measure and record the braking distance. - Standard measurement valve Braking distance......14 m (15 1/2 yd) or shorter - Possible causes of extremely long braking distance Possible cause

Solution

Low brake line pressure

Check and repair

Friction plate wear

Check and repair

Brake valve malfunction

Check and repair

The following method is easy and simple, however it is not an accurate way, because the braking force and rim-pull may vary on each machine. Confirm engine & transmission performance via using a stall test. See page 03-3. Reconfirm the brake performance by the method 1 as soon as possible.

WARNING Unexpected movement of the machine may cause an accident resulting in injury or death. Before starting brake performance check, be sure to observe the following items: - Place the machine on level ground. - Check that there is enough clearance for brake performance check around the machine. - During performance check, prohibit any person to walking near the machine. (1) Lower the boom to the lowest limit, and roll back the bucket fully until the bucket contacts to the stopper. (2) Set the parking brake switch to the "OFF" position. (3) Set the T/M (transmission) cut-off switch to OFF, and then depress the brake pedal all the way to the floor. (4) Set the shift lever to 2nd reverse speed. (5) Gradually increase the engine speed. The machine should not move at the maximum engine speed.

Note: The brake performance check methods 1 and 2 are based on the law and the regulation in Japan. When checking the service brake performance, follow the law and/or local regulation in your country, state, or province. 03-29

- Possible cause of machine moving during brake performance check. Possible cause

Solution

Low brake line pressure

Check and repair

Friction plate wear

Check and repair

Brake valve malfunction

Check and repair

Checking Brake Performance

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Parking brake performance check 1) Method 1

2) Method 2 If no test course available as described "Method 1", carry out the following method.

IMPORTANT The following method is easy and simple, however it is not an accurate way, because the braking force and rim-pull may vary on each machine. Confirm engine & transmission performance via stall test. See page 03-3. Reconfirm the brake performance by the method 1 as soon as possible.

WARNING - Condition (1) Test course 1/5 slope (Approx. 11° 19') (2) Bucket empty (3) Parking switch ON - Standard measurement No movement on 1/5 slope.

Unexpected movement of the machine may cause an accident resulting in injury or death. Before starting brake performance check, be sure to observe the following items: - Place the machine on level ground. - Check that there is enough clearance for brake performance check around the machine. - During performance check, prohibit any person to walking near the machine.

- Possible cause of machine moving during brake performance check Possible cause

(1) Set the parking brake switch to PARKING SOLINOID the "ON" position. (2) Disconnect the cable connector of parking brake solenoid valve. 65ZV03005 (3) Place the shift lever to the 3rd reverse position. (4) Gradually increase the engine speed. The machine should not move at the maximum engine speed.

Solution

Clearance between brake drum and Clearance adjustment shoe too large Improperly adjusted spring chamber link Check and adjustment Broken spring chamber spring

Check and repair

Parking brake solenoid valve malfunction Check and repair

IMPORTANT

If the machine begins to move with the parking brake applied, the brake shoes are burnt or misadjusted. At the completion of parking brake test, be sure to connect the connector of electrical line to the solenoid valve again. Possible cause

Solution

Clearance between brake drum and shoe too large Clearance adjustment Improperly adjusted spring chamber link

Check and adjustment

Broken spring chamber spring

Check and repair

Parking brake solenoid valve malfunction

Check and repair

03-30

Measuring Brake Line Oil Pressure

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Measuring Brake Line Oil Pressure WARNING

CAUTION

Be careful, you may get burned if the high pressure oil spouts out. To prevent such an accident, be sure to release the residual pressure from the pipe, and open the cap of the hydraulic oil tank before removing the plug and hose from the pressure measurement port.

(PPI)

(Z2)

(Z)

(Z1)

(PA)

ACF (PARKING)

(ACCF)

(ACCR) (PI)

(TA)

(T)

(P)

Warm up the hydraulic system before testing.

1. Brake line main pressure Brake line main pressure is regulated by the unloader valve. 1) Measuring unloader valve setting pressure - Measurement instrument Hydraulic pressure gauge: 19.6 MPa (200 kgf/cm2) (3,000 psi) - Gauge measuring port ACF port on valve assembly......Rc (PT) 1/8 - Measuring pressure (1) Lower the boom to the lowest limit, and tilt the bucket down to the ground. Then set the parking brake switch to the "ON" position. (2) Stop the engine. Repeatedly depress and release the brake pedal until the brake pedal resistance is gone. Then the accumulator pressure is discharged. (3) Remove the ACF port plug on the valve assembly and attach the pressure gauge to the port. (4) Start the engine, and keep the speed at low idle. Measure and record the pressure when the pointer of the pressure gauge stops rising (cutout pressure). (5) Keep the engine at low idle, and repeatedly depress and release the brake pedal to reduce the accumulator pressure. Measure and record the pressure when the pointer of the pressure gauge stops and then starts rising again (cut-in pressure). - Setting pressure Cut-out

11.8 ± 0.5 MPa (120 ± 5 kgf/cm2) (1,706 ± 71 psi)

Cut-in

6.9 ± 1.0 MPa (70 ± 10 kgf/cm2) (995 ± 142 psi)

ACF port

Valve assembly

65ZV03007

WARNING

Injection Hazard Depress brake pedal 80~100 times to completely discharge the brake accumulators prior to removing these test plugs. 65ZV03009

24 21

22 Fan motor port

Pump port

Unloader valve 65ZV03008

03-31

Measuring Brake Line Oil Pressure

70ZV

2) Adjusting unloader valve setting pressure - Adjusting procedure (1) Remove the cap nut (24) and loosen the lock nut (22). (2) Adjust the pressure by the adjusting screw (21). Turn the screw clockwise to raise the pressure. Note: In a case that the "ON" or "OFF" pressure does not match the standard setting pressure, set the "ON" (cut-in) pressure to the standard setting pressure. Tightening torque : N-m (kgf-m) (lb-ft) ACF port plug......11.3 (1.15) (8.3) #22......16.7 (1.7) (12) #24......78.5 (8.0) (58) Before disconnecting the gauge, hose, and fitting, discharge the accumulator pressure as described in (1) and (2) above in the measuring pressure.

03-32

MEASUREMENT FOR PERFORMANCE CHECK 03

Measuring Brake Line Oil Pressure

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

2. Measuring and adjusting accumulator line pressure Accumulator line pressure is regulated by the unloader valve. However, the reducing valve also may affect brake manifold pressure or accumulator pressure, as it is installed between the unloader valve and brake manifold. Measure pressure at the ACF ports to determine the manifold pressure when there is a brake pressure problem.

(PPI)

(Z2)

(Z)

(Z1)

(PA)

ACF (PARKING)

(ACCF)

(ACCR) (PI)

(TA)

(T)

(P)

1) Measuring reducing valve setting pressure - Measurement instrument Hydraulic pressure gauge: 19.6 MPa (200 kgf/cm2) (3,000 psi)

ACF port

- Gauge measuring port ACF port on valve assembly......Rc (PT) 1/8 - Measuring pressure Measure the pressure in the same way of measuring the unloader setting pressure. Note: In case the pressure is lower than the unloader cut-in pressure, adjust the reducing valve setting pressure to see if this may affect the pressure setting. It may have a stuck plunger or another malfunction.

Valve assembly 95ZV03014

Adjusting screw

Lock nut

2) Adjusting reducing valve setting pressure (1) Raise the setting pressure of the unloader valve to 12.7 MPa (130 kgf/cm2) (1,849 psi). (2) Loosen the lockout of the reducing valve and adjust the pressure by the adjusting screw. Turn clockwise the screw to raise the pressure.

Note: After raising the pressure to check function of valve, be sure to reset the unloader valve pressure to the original setting pressure. Tightening torque : N-m (kgf-m) (lb-ft) Lock nut......7.8 (0.8) (5.8) B

Reducing valve

03-33

70ZV53003

Measuring Brake Line Oil Pressure

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

● Possible cause of extremely high or low measurement value and solution Unloader valve The pressure is too low.

Possible cause

Solution

Inappropriate set unloader valve pressure

Adjustment

Debris stuck in pilot valve (poppet)

Disassembly & clean

Pilot spring broken

Disassembly & repair

Defect inside pilot pump

Disassembly & repair

Inappropriate set reducing valve pressure

Inspection & repair

Spring Spring

Poppet

The pressure is too high

Possible cause

Solution

Inappropriate set unloader valve pressure

Adjustment

65ZV03006

Reducing valve The pressure is too low.

Possible cause

Solution

Inappropriate set reducing valve pressure

Adjustment

Debris stuck in ball seat face

Disassembly & clean

Spring broken

Disassembly & repair

The pressure is too high.

Possible cause

Solution

Inappropriate set reducing valve pressure

Adjustment

Debris stuck in orifice

Disassembly & clean

Sticking plunger

Disassembly & clean

03-34

Measuring Accumulator Circuit Charging Time

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Measuring Accumulator Circuit Charging Time WARNING

CAUTION

(PPI)

(Z2)

(Z)

(Z1)

(PA)

ACF (PARKING)

(ACCF)

(PI)

(TA)

Warm up the hydraulic system before testing.

(T)

● Measurement instrument - Hydraulic pressure gauge : 19.6 MPa (200 kgf/cm2) (3,000 psi) - Stop watch ● Gauge installation position - Valve assembly ACF port : size Rc (PT) 1/8 ● Standard measurement value Engine speed : Low idle

(P)

ACF port

Valve assembly 95ZV03014

Unloader valve pressure ↑

3.9 MPa (40 kgf/cm2) (569 psi)

11.8 MPa (120 kgf/cm2) (1,706 psi)

(ACCR)

8 sec.

WARNING

● Measurement procedure 1.Lower the boom to the lowest limit, and tilt down the bucket to the ground. 2.Set the parking brake switch to the "ON" position. 3.Stop the engine. Repeatedly depress and release the brake pedal to discharge accumulator pressure. 4.Attach the pressure gauge to the valve assembly ACF port. 5.Start the engine, and keep the engine speed at low idle speed. 6.Measure and record the time from the low pressure alarm is turned off 3.9 ± 0.5 MPa (40 ± 5 kgf/cm2) (569 ± 71 psi) until the pointer of the pressure gauge stops rising 11.8 ± 0.5 MPa (120 ± 5 kgf/cm2) (1,706 ± 71 psi). 03-35

Injection Hazard Depress brake pedal 80~100 times to completely discharge the brake accumulators prior to removing these test plugs. 65ZV03009

Measuring Accumulator Circuit Charging Time

70ZV

● Possible causes of extremely high measurement value and solution Accumulator charging time is too long

Possible cause

Solution

Defective unloader valve

Disassembly & repair

Oil leakage from pipe

Check and repair

Defective pilot pump

Disassembly & repair

Accumulator charging time is too short

Possible cause Defective accumulator

Solution Repair or Replace

03-36

MEASUREMENT FOR PERFORMANCE CHECK 03

Measuring Number of Brake Pedal Applications

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Measuring Number of Brake Pedal Applications WARNING

CAUTION

Do not touch the fan or V-belt of the engine or a hig-temperature section if the engine is running. An accident resulting in injury may occur. Be sure to stop the engine before you open the side cover of the engine room.Keep all guards in place. Avoid high temperature components even when the engine is stopped.

● Standard measurement value

● Possible causes of extremely low measurement value and solution

Run engine 1 minute high idle, then stop the engine. Turn the key to the "ON" position. Step on the brake pedal and release, and check the number of times until the low pressure alarm is turned on 3.9 ± 0.5 MPa (40 ± 5 kgf/cm2) (569 ± 71 psi)

9 times or more

Possible cause

● Measurement procedure 1.Lower the boom to the lowest limit, and tilt down the bucket to the ground. 2.Set the parking brake switch to the "ON" position. 3.Run engine 1 minute high idle, then stop the engine. 4.Turn the starter switch to "ON". 5.Depress the right brake pedal all the way to the floor, and hold down the pedal for 5 seconds. Release the pedal, and wait for 5 seconds to depress the pedal again. Repeat. 6.Count and record the number of pedal applications until the low pressure alarm buzzer starts to sound.

03-37

Solution

Insufficient accumulator pressure due to defective unloader valve

Check and repair

Insufficient accumulator gas (N2) pressure

Charging

Insufficient accumulator pressure due to defective pilot pump

Check and repair

Defective brake valve

Check and repair

Defective service brake piston seal

Check and repair

Oil leakage from pipe

Check and repair

Measuring Declutch Engagement

70ZV

MEASUREMENT FOR PERFORMANCE CHECK 03

Measuring Declutch Engagement WARNING Brake performance check on a slope is dangerous work. An accident resulting in injury or death may occur. Before starting declutch engagement test observe the following: - Check that the slope is smooth. - Check that the brake works well. - Prohibit any person from walking into the dangerous - Determine the signs between the service men. - Do not enter the area near the moving machine.

70ZV03005J

● Measurement instrument - Chalk - Scale (approx. 1 m) (3 ft.) or tapemeasure - Thin rod (approx. 1 m) (3 ft.) used as measurement rod - Vinyl tape - Assistant / operator - Nylon tie straps (2 or 3) ● Warm-up the engine and transmission before measuring declutch engagement ● Standard measurement value 1/5 slope (approx. 11°19'), unloaded bucket, engine maximum speed at 1st speed position, quickly released inching pedal, the machine may roll only

15 cm (6 in) or less

● Cause of extremely high measurement value and solution Possible cause

Solution

Too much delay in resetting declutch switch

Check and replace declutch switch

Too much time lag in engaging clutch

Refer to "Time lag measurement procedure".

Measurement rod attached to step

● Measurement procedure 1) Park the machine on level ground. 2) Attach the measurement rod to the step. 3) Position the boom approximately 50 cm (11/2ft.) above the ground. Roll the bucket fully back until the bucket contacts to the stopper. 4) Stop the machine on a 1/5 slope (approx. 11°19') so that the machine is in the climbing direction (bucket up hill) . 5) Set the inching cut-off switch to ON. 6) Set the parking brake switch to the "OFF" position. 7) Press the inching brake pedal (left pedal) all the way to floor. 8) Mark the ground at the pointer position with chalk or tape. Increase the engine speed to its maximum, and set the transmission shift lever to the 1st forward speed. 9) Quickly release the inching brake pedal, and mark the point at which the machine stops rolling back (using the pointer) and starts moving up the slope. 10) Measure and record the distance on the slope.

03-38

Notes