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January 24, 2017
Structure Function Principle
CLG835H
Steering hydraulic system
a. For power steering, pressure oil flows into stator and rotor pair in certain proportion (flow amplify-
ing function) through spool and valve bushing pair to push rotor to rotate with steering wheel and
oil from plunger pump flows into left cavity or right cavity of steering cylinder to realize steering.
b. For manual steering, the stator and rotor pair of metering pump will play the role of oil pump to
press the oil in one cavity of steering cylinder to another cavity. Oil cylinder piston rod will push the
wheel to realize steering. Manual steering has low steering torque.
Installation and troubleshooting of metering pump
When installing, make sure that metering pump is concentric with steering column and there shall be
clearance in axial direction to avoid jacking of spool. Check whether turning is flexible after installation.
Fault and troubleshooting:
Faults
Symptom
Cause
Troubleshooting
methods
Oil leakage
Oil leakage in joint surface of parts
Dirt in joint surface
Check the joint surface
and clean it up
Oil leakage at front cover
Shaft seal ring is damaged
Replace the seal ring
Oil leakage in bolt (plug)
Insufficient tightening torque
of bolt (plug)
Tighten bolt (plug)
Heavy steering
Steering wheel is heavy when
turned quickly
Oil supply is insufficient
Check the oil pump and oil
supply line
Steering wheel is light when turned
slowly
Main priority valve spool is
stuck
Check whether the main
priority valve spool is flexi-
ble
Cylinder crawling
Air in steering system
Bleed air in the system
and check oil pump inlet
for air leakage
Foam in oil
Irregular noise
Heavy steering, no steering cylinder
action
Manual steering check valve
failure
Check whether the steel
ball exists and whether it is
chocked
No-load steering is light, heavy load
steering is heavy
Leakage caused by chocked
safety valve or safety valve
spring failure
Clean and check the
safety valve in priority
valve
Heavy steering
High hydraulic oil viscosity
Steering failure
No steering back to neutral position Leaf spring failure
Replace leaf spring
Pressure oscillation is significantly
increased, even no steering
Pull pin bend or broken
Rupture at linkage shaft pin
slot
Replace the pull pin or
linkage shaft
When you turn the steering wheel, it
immediately rotates in the opposite
direction or swings from side to side
Incorrect mutual alignment of
linkage shaft and rotor
Reassembly
No turning
Priority valve seizure, no oil at
CF port, LS port blocked
Summary of Contents for CLG835H
Page 2: ......
Page 4: ...Contents January 24 2017 CLG835H...
Page 6: ...1 2 General Information January 24 2017 CLG835H...
Page 38: ...1 34 Machine Inspection Table January 24 2017 CLG835H...
Page 156: ...3 2 Power Train System January 24 2017 CLG835H...
Page 214: ...3 2 Power Train System January 24 2017 CLG835H...
Page 272: ...3 60 Testing and adjustment January 24 2017 Power Train Test CLG835H...
Page 276: ...4 4 Hydraulic System January 24 2017 CLG835H...
Page 552: ...6 2 Driver s Cab System January 24 2017 CLG835H...
Page 608: ...7 2 Structure January 24 2017 CLG835H...
Page 662: ...8 4 Electrical System January 24 2017 CLG835H...
Page 677: ...8 19 January 24 2017 Structure Function Principle CLG835H Power System P18E00014...