Workshop Manual

5C–7
POWER–ASSISTED BRAKE SYSTEM
General Diagnosis
Condition Possible cause Correction
Brake Pull
Tire inflation pressure is unequal. Adjust
Front wheel alignment is incorrect. Adjust
Unmatched tires on same axle. Tires with approx. the same amount
of tread should be used on the same
axle.
Restricted brake pipes or hoses. Check for soft hoses and damaged
lines. Replace with new hoses and
new double“walled steel brake
piping.
Water or oil on the brake pads. Clean or replace.
Brake pads hardened. Replace
Brake pads worn excessively. Replace
Brake rotor worn or scored. Grind or replace.
Disc brake caliper malfunctioning. Clean or replace.
Front hub bearing preload incorrect. Adjust or replace.
Loose suspension parts. Check all suspension mountings.
Loose calipers. Check and tighten the bolts to
specifications.
Brake Roughness or Chatter
(Pulsates)
Excessive lateral runout. Check per instructions. If not within
specifications, replace or machine
the rotor.
Parallelism not within specifications. Check per instructions. If not within
specifications, replace or machine
the rotor.
Wheel bearings not adjusted. Adjust wheel bearings to correct
specifications
Pad reversed (steel against iron). Replace the brake pad and machine
rotor to within specifications.
Excessive Pedal Effort
Malfunctioning vacuum booster. Check the vacuum booster operation
and repair, if necessary.
Partial system failure. Check the front and rear brake
system for failure and repair. Also,
check the brake warning light. If a
failed system is found, the light
should indicate failure.
Excessively worn pad. Check and replace pads in sets.
Piston in caliper stuck or sluggish. Remove caliper and rebuild.
Fading brakes due to incorrect pad. Remove and replace with original
equipment pad or equivalent.
Vacuum leak to vacuum booster. Check for ruptured or loose hose.
Check the direction of check valve
within vacuum hose.
Correct vacuum hose direction.
Grease on the brake pads. Replace or clean.