BrakesBrake System Internal Leak Test
Brake System Internal Leak Test
Warning: Refer to
Brake Fluid Irritant Warning .
Caution: Refer to
Brake Fluid Effects on Paint and Electrical
Components Caution .
| 1. |
Start the engine and allow it
to idle. |
| 2. |
Apply light, steady pressure
to the brake pedal. Observe both the brake pedal feel and
travel. |
| 3. |
Release the brakes and turn
OFF the ignition. |
| 4. |
If the brake pedal apply felt
spongy, but the brake pedal travel was not excessive, perform the
following steps: |
| 5. |
If the brake pedal apply did
not feel spongy, but the brake pedal travel was excessive, perform
the following steps: |
| |
5.1 |
Loosen the master
cylinder-to-brake power booster mounting nuts. |
| |
5.2 |
Carefully pull the master
cylinder away from the brake power booster just enough to inspect
the mounting surface of the master cylinder. |
| |
5.3 |
Inspect the master cylinder
mounting surface at the primary piston (2) for brake fluid
leaks. |
| 6. |
If the master cylinder
exhibits any leakage around the primary piston (2), then the
primary piston primary seal (4) and/or secondary seal (3) is
leaking and the master cylinder requires overhaul or
replacement. |
| 8. |
If the brake pedal apply did
not feel spongy, and the brake pedal travel was initially steady
and not excessive, but then gradually fell, then the master
cylinder requires overhaul or replacement due to an internal leak
past the secondary piston (1) from the secondary piston primary
seal (6) or secondary seal (5). |
| 9. |
If the brake pedal apply did
not feel spongy, and the brake pedal travel was initially steady
and not excessive, then fell slightly, then became steady again,
then the brake pressure modulator valve (BPMV) may be leaking
internally, and may require replacement. |
|
|
07 Brakes
