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PARKING BRAKE MALFUNCTIONS
PARKING BRAKE MALFUNCTIONS
2)
2)
Problem
Cause
Remedy
Brakes chatter
Brakes chatter
Air in brake system.
Worn brake surface material.
Wrong oil in differential.
Do brake bleed procedure.
Inspect brake surface material.
Drain.Refill.
H i s s i n g n o i s e w h e n
H i s s i n g n o i s e w h e n
brake pedal is held with
brake pedal is held with
engine stopped
engine stopped
Leakage in brake valve, or brake
piston.
Do brake system leakage test.
Brake pressure warning
Brake pressure warning
light will not go out or
light will not go out or
stays on excessively long
stays on excessively long
after start-up
after start-up
M a l f u n c t i o n i n b r a k e l o w
pressure warning switch.
Brake accumulator pressure too
low.
L o w b r a k e p u m p s t a n d b y
pressure setting.
Leakage in pressure reducing
manifold block.
Leakage in brake system.
Worn brake pump.
L e a k a g e i n p a r k i n g b ra ke
solenoid.
Replace switch.
Recharge accumulator.
Do brake pump standby pressure test.
Do pressure reducing valve manifold leakage
test.
Do brake system components leakage tests.
Do brake pump flow test.
Do parking brake pressure test.
Problem
Cause
Remedy
Brake will not hold
Brake will not hold
Pads not adjusted correctly.
Malfunctioning parking brake
solenoid.
Worn brake disk and / or brake
pads.
Brake piston hangs up in bore.
Adjust parking brake.
Inspect and replace.
Disassemble, inspect, repair.
Remove and inspect. Repair.
Brake disk overheats
Brake disk overheats
Pads out of adjustment.
Brake not released.
Adjust parking brake.
Release parking brake.
Disassemble, inspect brake.
Repair if necessary.
Inspect for loosen or broken lines between brake
pressure switch and indicator on dash.
Parking brake indicator in
Parking brake indicator in
monitor does not come
monitor does not come
on when brake applied
on when brake applied
Faulty wiring or switch.
Inspect for loose or broken lines between brake
pressure switch and indicator on dash.
Inspect for a faulty indicator on dash. Replace if
necessary.
Brake will not apply
Brake will not apply
Pads out of adjustment.
Malfunctioning wiring, switch, or
solenoid.
Restriction between brake valve
and brake.
Adjust parking brake.
Check electric circuit.
Remove hose and inspect. Replace.
Summary of Contents for HL955
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