Checking the brake booster (VW Polo 4)

If an unusually high force is required on the brake pedal to achieve sufficient braking effect, the brake booster must be checked.

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.

If not, disconnect the vacuum hose at the brake booster 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.

Diesel engine: Disconnect the vacuum hose at the vacuum pump and check for vacuum at the vacuum hose connection.

If there is a vacuum, measure the vacuum and, if necessary, replace the brake booster (at a service station).