SkyTrak 6042 Service Manual - Manual (Page 247)

8.15 Model 6042 Legacy Origin 7/02
Hydraulic System
Not
OK
Not
OK
Not
OK
Not
OK
Not
OK
Not
OK
Check pressure at front axle.
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.
If park brake fails to
hold, check the “PBG”
port on the secondary
function manifold. Should
read 0 psi.
If park brake fails to
release, check the “PBG”
port on the secondary
function manifold. Should
read 550 psi (38 bar).
Check relief valve on
secondary function
manifold.
Refer to Section 9.15,
“Switches and Solenoids.”
Not
OK
Within the front axle:
If not holding, check the park
brake springs.
If not releasing, check the
piston seals.
Install seal kit/replace
solenoid valve cartridges.
If OK
Adjust/repair/replace
relief valve.
If OK
Check solenoid valve
cartridges.
Check solenoid valves on the
secondary function manifold.
Refer to ZF Axle Repair
Manual: Model MS-T 3045,
OmniQuip P/N 8990419
(ZF P/N 5871 550 002).
If OK
If OK
NOTE:
When checking pressures in
circuits, refer to Section 8.7,
“Hydraulic System Testing” for
correct pressure readings.
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
Not
OK
Check front and rear brake
discs for wear.
Refer to the appropriate
Owners/Operators Manual.
If OK
Not
OK
Check front brake
discs for wear.
Refer to the appropriate
Owners/Operators Manual.
If OK
Refer to ZF Axle Repair
Manual: Model MS-T 3045,
OmniQuip P/N 8990419
(ZF P/N 5871 550 002).