Kubota KX080-3 Workshop Manual page 415

WSM KX080-3 Service
c. Case - Study : Poor Manipulation and Abnormal Operation
Problems
8 Swivel stop can't be not locked. The swivel slow return check-valve is clogged with dirt.
The swivel motor relief valve is clogged with dirt.
The swivel motor relief pressure is too low.
9 An abnormal sound is heard when the 1) The swivel makeup filter is clogged.
swivel is stopped.
2) Failure of swivel negative brake release
3) Pressure escape due to brake seal failure
4) Damage to the friction plate
10 When the machine is jacked up, the R This phenomenon, which is caused by a difference in the piping pressure
and L revolutions differ from each other loss, is normal.
during idle traveling. (The machine trav-
els straight on a level ground.)
11 Traveling does not stop even when the 1) Dirt has caused the travel counterbalance spool to get stuck.
lever is returned to the neutral position
on a downward slope. (Poor travel
block performance)
12 When making a travel turn, the travel 1) Dirt has caused the travel counterbalance spool to get stuck.
section on the stop side turns together
and the machine goes straight.
2) A heat shock has caused the travel counterbalance spool to get stuck.
3) Travel lever return failure
4) The control valve spool has got stuck.
13 The traveling speed decreases to about 1) The set pressure of the relief valve for dozer UP (rod side) is too high.
one half when the dozer UP is relieved.
Probable causes
Disassemble and clean the check-valve.
Disassemble and clean the relief valve.
Measure and readjust the swivel relief pres-
sure.
1) Clean the filter.
1) Check the brake release pressure (pilot
primary pressure).
1) Check the brake seal. Replace it if nec-
essary.
1) Overhaul the brake unit.
Normal
1) Disassemble, clean and correct the
counterbalance spool.
1) Disassemble, clean and correct the
counterbalance spool.
1) Lift the body and warm up the travel
motor.
1) Check the travel lever link.
1) Disassemble and correct the spool in the
control section.
1) Measure and readjust the relief pressure
on the dozer UP side.
Remedies Ref.Fig.
Hydraulic system
IV-S-7