Checking the work
1. Press the pedal and start the engine. If the pedal drops slightly, then the vacuum booster is working properly.
2. Depress the brake pedal several times with the engine running and check that the brake pedal travel reserve is always the same.
Leak test
3. Start the engine and turn it off after a couple of minutes. Slowly depress the brake pedal several times. The brake pedal travel should decrease each time.
4. Depress the brake pedal with the engine running, then turn off the engine without releasing the brake pedal. If the pedal does not drop within 30 seconds, the booster is sealed.
Removal
1. Remove the brake master cylinder. Disconnect the vacuum hose from the booster.
2. Disconnect the booster pushrod from the brake pedal.
3. Unscrew the four mounting nuts and remove the amplifier.
Installation
1. Installation is carried out in the reverse order of removal.
2. Connect a vacuum pump to the booster and create a vacuum of 500 mmHg.
3. Measure the distance from the surface of the vacuum booster to the pusher – this is distance "A".
4. Measure the distance from the mounting flange to the end of the master cylinder - this is distance "B".
5. Measure the distance from the end of the master cylinder to the recess in the piston - this is distance "B".
6. Subtract the value "B" from the value "B", then subtract the resulting value from the value "A". The resulting value is the servo amplifier pushrod clearance.
7. Adjust the length of the push rod (1) if necessary by loosening the lock nut (2) and turning the push rod adjuster.