Hydraulic system – Lull 944E-42 Service Manual User Manual

Page 319

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8.67

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 OK

Replace Joystick

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.

NOTE:

When checking pressures in

circuits, refer to Section 8.7,

“Hydraulic System Testing,” for

correct pressure readings.

If the joystick is not

functioning.

NOTE:

Before pressure checking

circuits, refer to Section 9.8.30,

“Single Joystick - Auxiliary

Hydraulic

Circuit & Troubleshooting

(Option),” to ensure the electrical

circuits for the pilot select valve

are functioning properly.

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

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