Service Manual User guide

8.143
Model 644E-42/944E-42 Rev. 6/04
Hydraulic System
NOTE:
When checking pressures in
circuits, refer to Section 8.7,
“Hydraulic System Testing,” for
correct pressure readings.
If the auxiliary hydraulic
connection can’t connect
Not
OK
Push the auxiliary hydraulic
pressure release switch.
If OK
Refer to Section 9.14.5,
“Auxiliary Hydraulic Pressure
Release Switch 644E-42,
Not
OK
Check auxiliary hydraulic
pressure release valve.
NOTE:
Before pressure checking
circuits, refer to Section 9.8.29,
“Dual Joystick - Auxiliary
Hydraulic Circuit &
Troubleshooting,” to ensure the
electrical circuits for the pilot
select valve are functioning
properly.
Replace the release valve.
If the auxiliary hydraulic
connection can’t connect
or disconnect.
Before troubleshooting any
hydraulic circuit, ALWAYS
begin by checking the
following:
1. Hydraulic oil level in the
reservoir
2. All hoses, tubes, fittings
for leaks, kinks,
interference, etc.
3. Air in the lines