Checking the brake booster

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

With the engine off, depress the brake pedal strongly at least 5 times, then start the engine with the pedal depressed. The brake pedal should now feel good 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 being created.

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

If the car is equipped with 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 union for connecting the vacuum hose.

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