For 1990-2009 cars only
- With the engine stopped, eliminate the vacuum in the booster by pumping the brake pedal several times.
- Push the pedal down and hold it in this position.
- Start the engine.
- The booster is OK if the pedal drops further because of extra force produced.
- If the brake pedal does not drop, the vacuum system, vacuum hoses, check valve, etc., is probably defective and should be checked.
- If no defect is revealed by checking the vacuum system, the defect is in the booster itself.
