The brake booster is mounted between the brake pedal and the brake master cylinder. It helps reduce the force the driver must exert against the brake pedal in order for the brakes to work.
Symptoms of Wear or Failure
- Brake pedal may feel hard when pressed
- More force from the driver is needed to stop the vehicle
- Rough or high engine idle and/or illumination of the Check Engine Light (due to vacuum leak)
- Hissing type noise from brake pedal area when brakes are applied
Related Repair Advice
- We recommend using an OEM, factory quality brake booster replacement part and verifying that the brake master cylinder is not leaking any brake fluid. Leaking brake fluid can work its way into the brake booster housing and cause the new brake booster to fail prematurely.
- Excessive brake pedal stopping effort is not always caused by a defective brake booster. It can also be caused by engine vacuum leaks, glazed brake rotors and drums, very hard brake pads and shoes, or sticking, rusty disc brake calipers and drum brake components.