Kubota M5640SU Workshop Manual page 293

M5640SU, M5640DT-SU, WSM
1. TROUBLESHOOTING
Symptom
Implement Does Not
Rises (Not Noise)
(Noise)
Implement Does Not
Reach Maximum
Height
Implement Does Not
Lower
Implement Drops by
Weight
Implement Hunts
(Moves Up and
Down)
Probable Cause
Control linkage improperly assembled or
damaged
Control valve malfunctioning (unload valve,
spool, check valve, poppet valve)
Control valve broken
Control valve improperly adjusted
Relief valve spring damaged
Hydraulic piston O-ring, cylinder damaged
Safety valve damaged
Transmission fluid improper or insufficient
Oil filter clogged
Relief valve setting pressure too low
Relief valve spring weak or damaged
Hydraulic pump malfunctioning
Position rod and feedback rod improperly
adjusted
Lever stopper position improper
Control valve malfunctioning
Spool damaged
Poppet valve improperly adjusted (Adjusting
screw of poppet valve)
Lowering speed adjusting valve closed
Hydraulic cylinder worn or damaged
Hydraulic piston O-ring worn or damaged
Safety valve damaged
Lowering speed adjusting valve damaged
Check valve seat surface damaged (Control
valve malfunctioning)
Poppet valve seat surface damaged (Control
valve malfunctioning)
Poppet valve, poppet seat surface damaged
Check valve, check valve seat surface damaged
Control valve O-ring worn or damaged
Repair or replace
Repair or replace
Replace
Adjust
Replace
Replace
Replace
Change or replenish
Replace
Adjust
Replace
Repair or replace
Adjust
Adjust
Repair or replace
Replace
Adjust
Open
Replace
Replace
Replace
Replace
Replace
Replace
Replace
Replace
Replace
8-S1
HYDRAULIC SYSTEM
Reference
Solution
Page
8-S13
8-S12
8-S12
8-S12
8-S6
8-S14
8-S7
G-10
G-18
8-S6
8-S6
8-S15
8-S8
–
8-S12
–
–
–
8-S14
8-S14
8-S7
–
–
–
–
–
8-S12
9Y1210365HYS0001US0
KiSC issued 07, 2009 A