Hitachi ZW370 User manual

TO97C5-E-02ZW370 WHEEL LOADER TECHNICAL MANUAL OPERATIONAL PRINCIPLE
PRINTED IN JAPAN (E) 2018, 03
Service Manual consists of the following separate Part No.
Technical Manual (Operational Principle) : Vol. No.TO97C5-E
Technical Manual (Troubleshooting) : Vol. No.TT97C5-E
Workshop Manual : Vol. No.W97C5-E
TO97C5-E-02
PART NO.
Wheel Loader
Technical Manual
Operational Principle
URL:http://www.hitachi-c-m.com
ZW370

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October 2016
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.
General Information
Function and structure
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 meth-
ods. 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.
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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.
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.
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.
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CONTENTS
00 General Information ......................................................................................................................................... 00-1
How to Use Manual ........................................................................................................................................... 00-2
Safety precautions ...................................................................................................................................... 00-2
Symbols ...................................................................................................................................................... 00-3
Outline ............................................................................................................................................................... 00-4
Layout of main components ........................................................................................................................ 00-4
Inspection and maintenance table .............................................................................................................. 00-6
Recommended lubricants ........................................................................................................................... 00-9
Coolant ..................................................................................................................................................... 00-10
Lubrication chart ........................................................................................................................................00-11
Weight of main components ..................................................................................................................... 00-12
Bolt tightening torque ................................................................................................................................ 00-13
Hose band tightening torque ..................................................................................................................... 00-17
Liquid gasket and screw lock agent .......................................................................................................... 00-18
Cautions regarding welding repair service ................................................................................................ 00-20
03 Measurement for Performance Check ............................................................................................................. 03-1
Cautions on Safety ............................................................................................................................................ 03-2
Standard Measurement Values for Performance Check ................................................................................... 03-3
12 Function & Structure Chassis Group ................................................................................................................ 12-1
Front Chassis .................................................................................................................................................... 12-2
Loading linkage ........................................................................................................................................... 12-2
Loading linkage pin ..................................................................................................................................... 12-4
Rear Chassis .................................................................................................................................................... 12-5
Fuel tank ..................................................................................................................................................... 12-5
Floor board mount ....................................................................................................................................... 12-6
Center Pin ......................................................................................................................................................... 12-7
Upper center pin ......................................................................................................................................... 12-7
Lower center pin ......................................................................................................................................... 12-7
Dust seal ..................................................................................................................................................... 12-8
13 Check & Adjustment Chassis Group ................................................................................................................ 13-1
Linkage Pin ....................................................................................................................................................... 13-2
Liner ............................................................................................................................................................ 13-2
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Center Pin .........................................................................................................................................................13-5
Adjusting shim .............................................................................................................................................13-5
Grease nipple installation direction .............................................................................................................13-5
Installing bearing outer ring .........................................................................................................................13-5
22 Function & Structure Power Group ..................................................................................................................22-1
Power Line ........................................................................................................................................................22-2
Engine / Transmission .......................................................................................................................................22-4
Engine / transmission mount .......................................................................................................................22-4
Radiator (S/N 9001~9150) ................................................................................................................................22-5
Radiator (S/N 9151~) ........................................................................................................................................22-6
Propeller Shaft ..................................................................................................................................................22-8
Second propeller shaft assembly ................................................................................................................22-9
Third propeller shaft assembly ..................................................................................................................22-10
Axle Assembly ................................................................................................................................................. 22-11
Axle Support ....................................................................................................................................................22-12
Torque Proportioning Type Differential Gear (TPD) ........................................................................................22-14
Function of T.P.D .......................................................................................................................................22-17
Operation of T.P.D .....................................................................................................................................22-18
Limited Slip Differential (LSD) (option) ............................................................................................................22-19
LSD structure ............................................................................................................................................22-19
LSD function ..............................................................................................................................................22-23
LSD operation ...........................................................................................................................................22-23
23 Check & Adjustment Power Group ...................................................................................................................23-1
Engine ...............................................................................................................................................................23-2
Measuring engine speed .............................................................................................................................23-2
Measuring engine oil pressure ....................................................................................................................23-2
Propeller Shaft ..................................................................................................................................................23-3
Propeller shaft phase ..................................................................................................................................23-3
Second propeller shaft alignment ................................................................................................................23-3
Propeller shaft tightening torque .................................................................................................................23-4
Axle ...................................................................................................................................................................23-5
Axle nut tightening procedure .....................................................................................................................23-5
Differential gear adjustment procedure .......................................................................................................23-6
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32 Function & Structure Torque Converter and Transmission Group ................................................................... 32-1
Torque Converter .............................................................................................................................................. 32-2
Torque converter structure .......................................................................................................................... 32-2
Power flow path .......................................................................................................................................... 32-2
Torque multiplication ................................................................................................................................... 32-2
Torque Converter (Lock-up) (Option) ................................................................................................................ 32-3
Lock-up clutch structure .............................................................................................................................. 32-4
Lock-up clutch function (only forward) ........................................................................................................ 32-4
Torque Converter Gear Pump ........................................................................................................................... 32-6
Gear pump specifications ........................................................................................................................... 32-6
Gear pump specifications ........................................................................................................................... 32-7
Transmission ..................................................................................................................................................... 32-8
Clutch combination ..................................................................................................................................... 32-8
Planetary gear ............................................................................................................................................. 32-8
Shift lever position ....................................................................................................................................... 32-8
Downshift button operation ......................................................................................................................... 32-8
Gear train and number of teeth ................................................................................................................... 32-9
Clutch Pack ..................................................................................................................................................... 32-12
Power Flow Path in the Transmission ............................................................................................................. 32-13
Forward 1st speed power flow path .......................................................................................................... 32-13
Forward 2nd speed power flow path ......................................................................................................... 32-14
Forward 3rd speed power flow path .......................................................................................................... 32-14
Forward 4th speed power flow path .......................................................................................................... 32-15
Reverse 1st speed power flow path .......................................................................................................... 32-16
Reverse 2nd speed power flow path ......................................................................................................... 32-16
Reverse 3rd speed power flow path ......................................................................................................... 32-17
Hydraulic System Diagram ............................................................................................................................. 32-18
Hydraulic Circuit Diagram ............................................................................................................................... 32-20
Oil Flow ........................................................................................................................................................... 32-22
Oil flow in the torque converter line ........................................................................................................... 32-22
Oil flow to the clutch .................................................................................................................................. 32-22
T/C and T/M Oil Circulation ............................................................................................................................. 32-23
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Modulator Valve Unit .......................................................................................................................................32-25
Interior schematic (simple explanation) .....................................................................................................32-27
Modulator valve function ...........................................................................................................................32-28
Modulator valve operation .........................................................................................................................32-30
Control Valve Assembly ..................................................................................................................................32-32
Check valve ...............................................................................................................................................32-34
Clutch solenoid valve assembly ................................................................................................................32-35
Clutch valve assembly ..............................................................................................................................32-39
33 Check & Adjustment Torque Converter and Transmission Group ...................................................................33-1
Clutch Oil Pressure and Time Lag ....................................................................................................................33-2
Measuring clutch oil pressure .....................................................................................................................33-2
Measuring clutch time lag ...........................................................................................................................33-4
42 Function & Structure Hydraulic Group ..............................................................................................................42-1
Flushing Hydraulic Circuit .................................................................................................................................42-2
Purpose of flushing .....................................................................................................................................42-2
Cautions on Hydraulic Parts Replacement .......................................................................................................42-3
Hydraulic Circuit Symbols .................................................................................................................................42-4
Hydraulic lines .............................................................................................................................................42-4
Pumps & motors ..........................................................................................................................................42-4
Cylinders .....................................................................................................................................................42-4
Operation methods ......................................................................................................................................42-5
Pressure control valve .................................................................................................................................42-5
Flow control valve .......................................................................................................................................42-5
Directional control valve ..............................................................................................................................42-6
Check valve .................................................................................................................................................42-6
Miscellaneous hydraulic symbols ................................................................................................................42-7
Hydraulic System Operation .............................................................................................................................42-8
Hydraulic system operation outline .............................................................................................................42-8
Layout of Hydraulic Units ................................................................................................................................42-10
Hydraulic Tank ................................................................................................................................................. 42-11
Hydraulic Tank (S/N 9001~9300) .............................................................................................................. 42-11
Hydraulic Tank (S/N 9301~) ......................................................................................................................42-13
Hydraulic tank specifications .....................................................................................................................42-15
Hydraulic oil level check ............................................................................................................................42-16
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Hydraulic Pump ............................................................................................................................................... 42-17
Loading and pilot and brake pump/Steering pump ................................................................................... 42-17
Loading and pilot and brake pump/Steering pump specifications ............................................................. 42-17
Hydraulic pump principle ........................................................................................................................... 42-18
Hydraulic pump wear plate ....................................................................................................................... 42-19
Hydraulic pump bushing lubrication .......................................................................................................... 42-19
Hydraulic Cylinder ........................................................................................................................................... 42-20
Boom cylinder ........................................................................................................................................... 42-20
Bucket cylinder .......................................................................................................................................... 42-20
Steering cylinder ....................................................................................................................................... 42-21
Hydraulic cylinder specifications ............................................................................................................... 42-22
Loading System .............................................................................................................................................. 42-23
Reducing Valve (for Pilot Pressure) ................................................................................................................ 42-24
Pilot valve (S/N 9001~9250) ........................................................................................................................... 42-25
Pilot valve (S/N 9251~9255) ........................................................................................................................... 42-30
Pilot valve (S/N 9256~) ................................................................................................................................... 42-35
Multiple Control Valve (KML35A/2T003B) ....................................................................................................... 42-40
Multiple control valve specifications .......................................................................................................... 42-41
Multiple control valve main relief valve ..................................................................................................... 42-42
Multiple control valve overload relief valve (with make-up function) ......................................................... 42-44
Multiple control valve make-up valve ........................................................................................................ 42-45
Multiple control valve bucket spool ........................................................................................................... 42-46
Multiple control valve boom spool ............................................................................................................. 42-48
Adapter (Orifice) .............................................................................................................................................. 42-51
Ride Control (OPT) ......................................................................................................................................... 42-52
Ride control hydraulic circuit ..................................................................................................................... 42-52
Ride control operation ............................................................................................................................... 42-53
Ride control valve assembly (Reducing valve circuit) ............................................................................... 42-55
Ride control valve assembly (Accumulator circuit) ................................................................................... 42-58
Accumulator (for ride control) .................................................................................................................... 42-61
Steering System .............................................................................................................................................. 42-62
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Orbitrol®...........................................................................................................................................................42-63
Orbitrol®structure .....................................................................................................................................42-63
Orbitrol®specifications ..............................................................................................................................42-64
Orbitrol®operation ....................................................................................................................................42-65
Orbitrol®feed-back mechanism operation ................................................................................................42-67
Steering speed and flow rate control .........................................................................................................42-68
Hydraulic pump oil amount and steering force ..........................................................................................42-68
Orbit rotor operation principle ....................................................................................................................42-69
Steering Valve (KVS32-A4.0/20) .....................................................................................................................42-70
Steering valve operation ...........................................................................................................................42-72
Steering spool variable throttle ..................................................................................................................42-74
Steering valve flow control spool ...............................................................................................................42-75
Steering valve main relief valve ................................................................................................................42-76
Steering valve overload relief valve ..........................................................................................................42-78
Steering pilot circuit and its operation .......................................................................................................42-80
Stop Valve .......................................................................................................................................................42-82
Stop valve function ....................................................................................................................................42-83
Stop valve operation .................................................................................................................................42-83
Reducing Valve (for Orbitrol®) .........................................................................................................................42-84
Steering Line Filter ..........................................................................................................................................42-85
K-Lever (OPT) .................................................................................................................................................42-86
Hydraulic circuit .........................................................................................................................................42-86
Hydraulic line diagram ...............................................................................................................................42-87
Hydraulic line .............................................................................................................................................42-88
Solenoid valve mount ................................................................................................................................42-89
Solenoid valve assembly (1/2) ..................................................................................................................42-90
Solenoid valve assembly (2/2) ..................................................................................................................42-91
Efficient Loading System .................................................................................................................................42-92
Efficient loading system outline .................................................................................................................42-92
Mounting of the ELS valve ........................................................................................................................42-93
Mounting of the variable kickout sensor ....................................................................................................42-94
Efficient loading system operation ............................................................................................................42-95
Fan Motor System ...........................................................................................................................................42-96
Mounting of fan motor ...............................................................................................................................42-96
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