Hydraulic system – Lull 944E-42 Service Manual User Manual
Page 315
8.63
Model 644E-42/944E-42
Rev. 6/04
Hydraulic System
Not
OK
Replace capsules or o-ring
seals.
Not
OK
Check the pilot pressure at
“PPG” port of accumulator
charge/secondary function
valve.
If OK
Adjust the pressure reducing
cartridge on the accumulator
charge/secondary function
valve.
Check capsules or seals in
joystick valve body.
If the joystick is not
functioning.
NOTE:
When checking pressures in
circuits, refer to Section 8.7,
“Hydraulic System Testing,” for
correct pressure readings.
If OK
Replace Joystick
NOTE:
Before pressure checking
circuits, refer to Section 9.8.29,
Troubleshooting,” to ensure the
electrical circuits for the pilot
select valve are functioning
Not OK
Install new seal kit in the
pressure reducing cartridge
on the accumulator charge/
secondary function valve.
Not OK
Replace the pressure
reducing cartridge on the
accumulator charge/
secondary function valve.
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