Lull 944E-42 Service Manual - Manual (Page 323)

8.71 Model 644E-42/944E-42 Rev. 6/04
Hydraulic System
Not
OK
Not
OK
Not
OK
Check pressure at front and
rear axles.
If service brakes are not
holding, check the pressure
at the brake valve.
Replace brake valve.
Check the brakes for
mechanical failure.
If OK
Replace brake valve.
Refer to ZF Axle Repair
Manual, Model MS-T 3045,
ZF part # 5871 550 002. JLG
part # 8990419 (644E Only)
or ZF Axle Repair Manual,
Model MS-T 3060, ZF part #
5871 560 002. JLG part #
8990430 (944E Only)
If OK
NOTE:
When checking pressures in
circuits, refer to Section 8.7,
“Hydraulic System Testing,” for
correct pressure readings.
Not
OK
Check front and rear brake
discs for wear.
Refer to Section 5.6.1, “Brake
Disc Inspection.”
If OK
Check the function of the
accumulator charge/
secondary function valve.
See “Accumulator Charge/
Secondary Function Valve”
on page 8.204.
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