Ls Control System Troubleshooting; Procedures For Hydraulic Pilot System Troubleshooting - Kubota KX080-3 Workshop Manual

WSM KX080-3 Service
d. LS control system troubleshooting
(1) General
The core of the hydraulic system corprated in KX080-3 is a combination of horsepower control and LS
control.
Trouble with the hydraulic system is therefore attributed chiefly to hydraulic equipment such as pumps
and control valves.
There may be cases where the hydraulic pilot system that controls the stroke of a control valve spool
is secondarily involved in trouble.
Of course, individual actuators may have trouble.
Troubleshooting is therefore performed in the following four portions to determine the causes of trou-
ble with the hydraulic system.
1) Pilot control system
2) Control valve
3) Pump
4)Actuators

(2) Procedures for Hydraulic Pilot System Troubleshooting

1) All the hydraulic pilot
sections are inoperative.
2) All the right or left
pilot sections are inoperative.
3) Any one hydraulic
pilot system is inoperative.
(Both A and B ports)
4) Either A or B in any
one hydraulic pilot section
is inoperative.
Pilot pump
Change valve(Unload valve)
Pilot valve, L&R
Pilot filter
High pressure selector popet
Compensation spool
Relief valve(Main, overload)
Unload valve
LS regurator
Horse power control pin, spool
Control pin
Cylinders
Swivel motor
Travel motor(Rotary joint)
Change valve(Unload valve)
Pilot filter
Pilot valve
Stick of the control spool in
the neutral position
Stick of the relevant spool of the pilot valve
(The case where both A and B are abnormal
is rare.)
Stick of the relevant spool of the pilot valve
Stick of the control valve spool on one side
IV-S-9
Hydraulic system