Troubleshooting - wsm STW37 Workshop Manual

STW34, STW37, STW40, WSM

1. TROUBLESHOOTING

Symptom
Implement Does Not
Rise (Without Relief
Valve Function Noise)
Implement Does Not
Rise (With Relief
Valve Function Noise)
Implement Does Not
Reach Maximum
Height
Implement Does Not
Lower
Probable Cause and
Checking Procedure
1. Control linkage is adjusted
improperly.
2. Control linkage improperly
assembled or damaged.
3. Position control valve is
damaged.
(unload poppet, spool,
popper 1, 2)
4. Relief valve spring is
weaken or damaged.
5. Auxiliary control valve is
damaged.
1. Hydraulic piston O-ring or
cylinder is damaged.
2. Transmission fluid is
improper or insufficient.
3. Hydraulic oil filter is
clogged.
4. Suction pipe is loosen or
damaged.
5. Suction pipe O-ring is
damaged.
6. Relief valve setting
pressure is too low.
7. Relief valve spring is
weaken or damaged.
8. Hydraulic pump is
damaged.
1. Position control feedback
rod is adjusted improperly.
2. Top link length is adjusted
improperly.
3. Position control valve
spool joint is adjusted
improperly.
4. Hydraulic arm shaft,
hydraulic arm or lift arm is
assembled improperly.
1. Position control valve is
damaged.
– Spool damaged.
2. Position control valve is
damaged.
– Poppet 2 or adjusting
set screw is adjusted
improperly.
Solution
Adjust control linkage.
Repair or replace control linkage.
Repair or replace position control valve.
Replace relief valve spring.
Repair or replace auxiliary control valve.
Replace hydraulic piston O-ring or
cylinder.
Change or fill transmission fluid.
Replace hydraulic oil filter.
Repair or replace suction pipe.
Replace O-ring.
Adjust relief valve setting pressure.
Replace relief valve spring.
Repair or replace hydraulic pump.
Adjust position control feedback rod.
Adjust top link length.
Adjust position control valve spool joint.
Assemble the hydraulic arm shaft, the
hydraulic arm and the lift arm properly.
Replace spool.
Adjust the poppet 2 and the adjusting set
screw properly.
8-S1
HYDRAULIC SYSTEM
Reference
Page
8-S11
8-S11
8-S17
8-S12
3-S24,
3-S36
8-S18
G-8
G-19
–
–
8-S12
8-S12
8-S14
8-S11
–
8-S17
8-S19
8-S17
8-S17
KiSC issued 11, 2014 A