G874174P10: Excessive/Erratic Brake Pedal Travel

PINPOINT TEST G874174p10: EXCESSIVE/ERRATIC BRAKE PEDAL TRAVEL

G874174t33: TEST ON ROUGH ROAD

1. Road test the vehicle on rough road conditions.
2. Apply the brakes slowly.

^ Is the brake pedal effort and brake pedal travel normal?

-> Yes
Vehicle is OK.

-> No
GO to Pinpoint Test G874174t34.

G874174t34: CHECK BRAKE FLUID LEVEL

1. Check the brake master cylinder reservoir fluid level.

^ Is the fluid level OK?

-> Yes
GO to Pinpoint Test G874174t35.

-> No
CHECK brake master cylinder reservoir sealing points. Refer to Brake master cylinder component test. Brake Master Cylinder ADD brake fluid and BLEED the brake system. TEST the system for normal operation. REPEAT road test if necessary.

G874174t35: CHECK BRAKE PEDAL RESERVE

1. Run engine at idle speed.
2. Apply the brake pedal lightly three or four times.
3. Wait 15 seconds for the vacuum to replenish.
4. Push down on the brake pedal until it stops moving downward or an increased resistance to the brake pedal travel occurs.
5. Hold the brake pedal in the applied position while increasing the engine speed to 2000 rpm.
6. Release the accelerator pedal.

^ Does the brake pedal move downward as the engine speed returns to idle?

-> Yes
GO to Pinpoint Test G874174t36.

-> No
CHECK the vacuum to the brake booster.

G874174t36: CHECK THE FRONT WHEEL BEARING ASSEMBLY

1. Check the front wheel bearing assembly.

^ Are the front wheel bearings loose?

-> Yes
INSTALL a new front wheel bearing if damaged.
TEST the system for normal operation.

-> No
CHECK the front brake discs for thickness variances.