Checking the work
1. Press the brake pedal several times with the engine off. The pedal travel should not change with each press.
2. Press the pedal and start the engine – the pedal should move forward slightly.
Checking for leaks
1. Start the engine, stop it after 1–2 minutes.
2. Press the pedal slowly several times – the pedal stroke should gradually decrease.
3. Start the engine and press the pedal.
4. Keeping the pedal pressed, stop the engine – the pedal position should not change within 30 seconds after stopping.
Removal
If the amplifier is faulty, it will need to be replaced; repairing the unit is impossible even in a car service center.
1. Remove the master cylinder.
2. Remove the driver's side knee pad and locate the booster pushrod fork (the arrows indicate the pushrod fork axle cotter pins and brake booster mounting nuts).
3. Unsplit the fork axle.
4. While holding the pushrod fork, loosen the pushrod locknut.
5. Disconnect the hose from the brake booster.
6. Remove the four nuts securing the brake booster to the engine compartment bulkhead.
7. Carefully feed the amplifier and remove it when the studs come out of the bulkhead.
Installation
1. Installation is carried out in reverse order.
2. If a new unit is installed, adjust the protrusion of the master cylinder pushrod above the booster housing. To do this, do the following.
3. Measure the tappet protrusion. This is dimension A.
4. Measure the distance from the end of the master cylinder to the flange. This is dimension B.
5. Measure the distance from the end of the cylinder to the bottom of the piston recess. This is dimension C.
6. The gap between the pusher and the piston is (B – C) – A and should be equal to 0.
7. Rotate the push rod tip to set the protrusion A so that the gap is equal to B – C. Check the gap again.
8. Repeat adjustment if necessary.
9. Once finished, install the master cylinder, connect the tubes, adjust the pedal height and free play (see subsection 2.34).
10. Remove air from the hydraulic drive.