JLG sky trak mmv Service Manual page 315

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
NOTE:
When checking pressures in
circuits, refer to Section 9.7,
Hydraulic System Testing for
correct pressure readings.
Model MMV Rev. 12/04
If service brakes are not
holding, check the pressure
at the brake valve.
If OK
Check pressure at front axle.
If OK
Check front and rear brake
discs for wear.
If OK
Check the brakes for
mechanical failure.
Hydraulic System
Not
Replace brake valve.
OK
Not
Replace brake valve.
OK
Refer to Section 2.13.12,
Not
OK
Brake Disc Wear Check .
Refer to ZF Axle Repair
Manuals:
(Front) Model MS-T 3060,
Not
ZF part # 5871 560 002
OK
JLG part # 8990430
(Rear) Model MS-T 3045,
ZF part # 5871 550 002
JLG part # 8990419
9.17