Vacuum booster — testing (Opel Omega A)

1. To check whether the servo motor is working or not, please do the following.

2. After the engine stops, press the brake pedal several times to dissipate the vacuum from the servo motor unit.

3. With the brake pedal depressed, start the engine. The pedal should move slightly toward the floor with additional assistance from the servo motor unit. If this does not happen, check the vacuum hose and check valve. If they work, the booster itself is defective and should be replaced.