When checking the brake booster for leaks, make sure that it is completely sealed to the brake master cylinder. If there is a leak, replace the gasket (A).
Checking the tightness of the brake booster should be performed on vehicles with serviceable hydraulic wiring.
Connect the device between the brake booster and the vacuum source (intake manifold) using a "tee" and as short a hose as possible.
Start the engine and let it idle for about 10 minutes.
Clamp the hose between the "tee" and the vacuum source using the device (Ms. 583) (1).
If the vacuum decreases by more than 33 mbar in 15 seconds, this indicates the presence of a leak, which may occur:
- in the area of the check valve (replace it),
- pusher diaphragm (the brake booster must be replaced).
If the vacuum booster is faulty, the brake system will still function, but the force applied to the brake pedal for effective braking will be significantly greater than with a functioning booster.