Counterbalance Valve Function Troubleshooting - Kubota KX080-3 Workshop Manual

WSM KX080-3 Service
(2)Counterbalance valve function
Trouble
1. Motor will not rotate or rotates but
slow.
2. Motor will not stop or stops but
slow.
3. Machine is shocked severely
when traveling is stopped.
4. Abnormal noise is heard.
Possible Cause
Plunger does not switch.
1) Hydraulic pressure is not gener-
ated.
2) Foreign matter exists between
the plunger and the base plate.
3) Orifice is clogged.
Plunger does not return to neutral.
1) Foreign matter exists between
the plunger and the base plate.
2) Spring is not set properly.
3) Spring is damaged or broken.
4) Orifice is clogged.
Plunger returns too quickly.
Spring seat is not set properly.
Plunger notch restricts oil flow.
1) Foreign matter exists between
the plunger and the base plate.
2) Spring is damaged or broken.
3) Orifice is clogged.
IV-S-19
Remedy
Check whether piping is damaged
or not.
Remove foreign matter completely.
Repair damaged part and
assemble it after cleaning. If the
damage and leakage are severe,
replace the part.
Clean it with washing oil and re-
assemble.
Remove foreign matter completely.
Repair damaged part and
assemble it after cleaning. If the
damage and leakage are severe,
replace the part.
Set the spring at proper position.
Replace the spring. Remove foreign
matter completely. Repair damaged
part and re-assemble it after clean-
ing.
Clean it with washing oil and re-
assemble.
Orifice plug came off
Set the spring seat at proper posi-
tion.
Remove foreign matter completely.
Repair damaged part and
assemble it after cleaning. If the
damage and leakage are severe,
replace the part.
Replace the spring. Remove foreign
matter completely. Repair damaged
part and re-assemble it after clean-
ing.
Clean it with washing oil and re-
assemble.
Hydraulic system
re-
re-
re-