Checking the brake booster (VW Passat B3)

The brake booster should be checked when an unusually high force must be applied to the brake pedal to achieve sufficient braking effect.

With the engine off, press the brake pedal hard at least 5 times, then start the engine with the pedal pressed. Now the brake pedal should be easy to feel under your foot.

Otherwise, unscrew the brake booster vacuum hose and start the engine. Place your finger on the end of the vacuum hose to check if a vacuum is created.

If there is no vacuum: check the vacuum hose for leaks and damage, replace the hose if necessary. Tighten all clamps securely.

If the vehicle has a diesel engine, disconnect the vacuum hose from the vacuum pump and check with your finger whether a vacuum is created at the inlet of the vacuum hose connection nipple.

If there is a vacuum: measure the vacuum, replace the brake booster if necessary (workshop work).