Power Brake Booster
- Run engine for 1-2 minutes, and then turn off. Depress brake pedal several times using normal foot pressure. Maximum travel should be obtained on first brake application, and pedal should gradually rise after each following application. If okay, proceed to next step.
- With engine stopped, depress brake pedal several times. Hold brake pedal down and start engine. If brake pedal goes down slightly, power brake booster is functioning properly.
- With engine running, depress brake pedal and turn engine off. Hold pedal down for 30 seconds. If pedal height does not change, power brake booster is functioning properly. If all tests are okay, power brake booster is in good condition. If tests results are not as stated, check vacuum hose, vacuum supply and vacuum check valve before replacing power brake booster.