Kubota KX080-4 Workshop Manual page 326

KX080-4, WSM
Slow during multiple operations
No. Cause
Seat of unload LS valve (aUN) faulty
1
Seat of main LS valve (aLS) faulty
2
Horsepower control valve faulty or loose
3
[3] TRAVEL SYSTEM TROUBLESHOOTING
Fails to travel right and left or is slow
• It is unlikely that the right and left pilot valve, travel motor, control valves (travel section), etc. would become faulty
at the same time.
• If neither right nor left will travel, it is likely a common pilot system is faulty.
• Adjust the left/right track tension and get rid of any clumps of mud.
No. Cause
1 Travel pilot valve filter blockage
Pp2, Pp4 filters and/or orifices
2
blocked
Independent travel valve's sub-spool
3
and/or main spool sticking
One side fails to travel, is slow or meanders
No. Cause
Defective travel pilot valve
1
Travel main relief valve faulty
2
Main spool inside control valve or
travel section is sticking or damaged
3
Defective travel motor
4
Swivel joint faulty
5
• Measure unload LS valve pressure
1. Disassemble and clean or replace the relief valve
• Measure main LS valve pressure
1. Disassemble, clean and adjust or replace the relief valve
Check and adjust for loose nuts
Remedy
Clean the pilot valve filter
Clean the filters and orifices
• Inspect and replace the sub-spool and/or main spool
1. Take the sub-spool and/or main spool out of the control valve and
clean it.
2. After applying hydraulic oil, check whether it slides properly and
return to the control valve.
Remedy
• Measure the pilot secondary pressure
• Temporarily swap main relief valves forwards/backwards or left
right.
[Assessment]
If problem swaps forwards/backwards or left-right: travel main relief
valve is faulty
If problem is the same: the main spool is sticking or damaged or the
swivel joint and/or travel motor are faulty
• Swap the left-right travel hoses on the control valve side and see
if the problem changes sides too.
[Assessment]
If problem switches sides: main spool is sticking or damaged
If problem doesn't change: swivel joint and/or travel motor are faulty
• Measure the drain volume
[Assessment]
If within factory specs: swivel joint is faulty
If outside specs: travel motor is faulty
• Swap the left/right travel hoses (swivel joint to travel motor) on the
swivel joint side and see if the problem changes sides too.
3-S167
Remedy
HYDRAULIC SYSTEM
Notes
RY9212148HYS0362US0
Notes
RY9212148HYS0364US0
Notes
RY9212148HYS0365US0
KiSC issued 08, 2015 A