10 - 1
FAULT
A One or both brakes do not apply.
(Brake travel not excessive, brakes
not pulling to one side).
B Pedal travel excessive (but not
touching floor).
C Applying one brake (pedals
unlocked) also partially engages
the other brake.
D Pedal hard to operate.
E Pedals touch floor under constant
pressure - no fluid loss.
F Pedals touch floor under constant
pressure - and fluid loss.
G Pulling to one side when pedals
locked together.
Brake System
Note: The brakes generate a high temperature when operating, this means that the casing will be hot to touch, this condition
is normal.
POSSIBLE CAUSE
1 Master cylinder fault.
2 Friction/counter plate distortion.
1 Air in hydraulic system.
2 Leak in hydraulic system.
3 Friction/counter plate distortion.
1 Valve stem seal inside (non-active)
master cylinder piston not sealing.
1 Tightness at pedal pivot.
2 Fluid contamination/seal damage.
3 Misaligned push rod/pedal.
4 Kinked or crushed brake pipes.
1 Master cylinder fault.
2 Friction/counter plate distortion.
3 Air in hydraulic system.
1 External fluid leaks.
2 Internal fluid leaks.
1 Compensating feature not
working.
ACTION
1 Check master cylinder in single and
coupled pedal modes to identify fault
area, service as required.
2 Check friction/counter plates.
1 Check fluid reservoir level. Check for
fluid/air leaks, rectify as required.
2 Check for fluid loss at master
cylinder and brake piston, all pipes
and fittings for loose connections.
Rectify as required.
3 Renew friction/counter plates -
BOTH sides.
1 Renew master cylinder piston.
1 Inspect pedal pivot. Free-
off/lubricate.
2 Flush system and renew all hydraulic
seals.
3 Check and rectify as required.
4 Check/renew brake pipework.
1 Check master cylinder in single and
coupled pedal modes to identify fault
area, service as required.
2 Renew friction/counter plates -
BOTH sides.
3 See item B.1.
1 Visually check brake circuit for fluid
loss, service as required.
2 Refer to Service Procedures -
Brake Piston Seal Leakage Test.
1 Inspect master cylinder
compensating operation. Check if
blockage in bridging pipe. Service as
required.
Section G Brakes
9803/7130
Section G
10 - 1
Issue 1
Fault Finding
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