Brake Booster

Inspect the brake booster for the following:

• Excessive corrosion or damage
• Vacuum connections for leakage
• Vacuum hoses for kinks or leakage
• Brake booster check valve for correct operation

Changes in the brake pedal feel or travel are indicators that something could be wrong in the brake system. GO to SYMPTOM CHART  for abnormal condition diagnosis.

1. With the transmission in NEUTRAL and the engine stopped, apply the brakes several times to exhaust the vacuum in the vacuum boost system or the pressure in the Hydro-Boost system.
2. Hold the brake pedal in the applied position.
3. Start the engine.
4. If the power brake system is functioning correctly, the brake pedal can be felt to move downward after the engine starts.
5. With a vacuum type power brake booster, if engine vacuum is available to the power brake booster and no power assist is felt, replace the power brake booster and retest the system.

   If power steering pump pressure is available to the Hydro-Boost power brake booster and no power assist is felt, replace the Hydro-Boost power brake booster and retest the system.

   If power steering pump pressure is not available at the Hydro-Boost power brake booster, check the power steering pump pressure and flow. For additional information, refer to Section STEERING SYSTEM - GENERAL INFORMATION .

   On a Hydro-Max booster system, if power is available at the electric pump and no power assist is felt, replace the Hydro-Max booster assembly and retest the system.

   If power is not available at the electric pump, correct the electrical concern and retest the system.