What is the Vacuum Booster all about?
Today’s braking systems use a number of different components, one of which is called the vacuum booster, or brake booster. It is the main component in the power brake system. The vacuum booster is attached to the brake master cylinder, and sits between the master cylinder and the firewall on the driver’s side, to the rear of the engine compartment. It has a rod that extends into the brake master cylinder to create line pressure, forcing the caliper to squeeze the brake rotors. The vacuum booster ‘boosts’ brake pedal pressure with vacuum to make it easier to press the pedal.
Keep in mind:
- The vacuum booster is a sealed component and is difficult to inspect.
- A leaking check valve can produce the same symptoms as a failed vacuum booster.
How it's done:
- The brake master cylinder is removed for to gain access to vacuum booster
- The defective vacuum booster is removed from the firewall and brake pedal
- The new vacuum booster is installed and connected to the brake pedal
- The brake master cylinder is reinstalled and brakes are bled of air
- The vehicle is road tested for proper brake operation
The vacuum booster does not require any maintenance and is designed to last the lifetime of your vehicle. It is possible, though very rare, for an internal failure to occur. If that is the case, have one of our expert technicians diagnose the vacuum booster.
What common symptoms indicate you may need to replace the Vacuum Booster?
- Brake pedal is extremely hard to press
- Stopping distance is increased
- Brake pedal feel is inconsistent on the same application
How important is this service?
While a failed vacuum booster will not render the brakes completely dysfunctional, it will make the brakes much harder to apply. Stopping distance is increased, which poses a safety risk in short braking situations. Have a faulty vacuum booster replaced immediately.