What is the Vacuum Brake Booster Check Valve all about?

The vacuum brake booster check valve is part of the brake booster, and plays an essential role in brake system operation. It is a one-way valve that allows air to be sucked out of the booster, but does not allow air to enter it. This is a safety solution to ensure that if the engine is turned off, or if frequent stops or pedal presses are required, the brakes still operate. Its capacity ensures that you have enough boost for several brake applications. The vacuum brake booster check valve connects the vacuum hose from the engine to the body of the brake booster.

Keep in mind:

• The vacuum brake booster check valve is not designed to require maintenance, so it will not be inspected during routine services.
• Damage to the vacuum hose from the engine can mimic problems with the check valve.

How it's done:

• The faulty vacuum brake booster check valve is located and identified
• The vacuum brake booster check valve is removed
• The new vacuum brake booster check valve is installed
• The brakes are tested for proper vacuum brake booster check valve operation
• The vehicle is road tested and checked for proper vacuum brake booster check valve and brakes operation

Our recommendation:

Many different issues can create problems with the braking system, including air in the lines, dirty/burned brake fluid, and more. If you suspect a vacuum brake booster check valve issue, have one of our expert mechanics diagnose it.

What common symptoms indicate you may need to replace the Vacuum Brake Booster Check Valve?

• Brake pedal feels spongy when pressed
• Brake pedal is very hard to press
• Brake pedal begins as easy to press then becomes very difficult

How important is this service?

While a leak in the vacuum brake booster check valve will not eliminate your ability to stop, it will make braking much more difficult and increase your stopping distance. It should be repaired as soon as possible.