Examination
1. During operation, this unit does not require any maintenance. You should only check the condition of the hose and the amplifier body.
2. To check the operation of the booster, press the brake pedal several times with the engine off. The pedal travel should not change with each press (checked by the distance to the floor).
3. Press the pedal and start the engine – the pedal should move forward slightly.
4. Start the engine, stop it after 1-2 minutes. Press the pedal hard several times – the pedal stroke should gradually decrease.
5. Start the engine and press the pedal. Keeping the pedal pressed, stop the engine – the pedal position should not change within 30 seconds after stopping.
6. If the amplifier is faulty, it will need to be replaced.
Removal
1. Disconnect the hose from the amplifier (indicated by the arrow).
2. Loosen the master cylinder nuts and carefully remove the cylinder from the studs.
3. In the passenger compartment, unpin the axle and detach the pedal spring (the pusher axis and spring are indicated by arrows). Remove the axle and disconnect the pushrod fork from the pedal.
4. Loosen the booster mounting nuts (indicated by arrows) to the engine compartment bulkhead.
5. Carefully feed the amplifier and remove it when the pins come out of the bulkhead.
Installation
1. Installation is performed in reverse order. Replace the axle pin. Adjust the brake pedal.
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 taking into account the gasket (1 - clearance). This is dimension A. There should be no clearance between the tappet and the cylinder piston, otherwise the brake pedal travel will increase. On the other hand, the tappet should not rest excessively against the piston, since braking will be incomplete.
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 clearance between the tappet and the piston is (B - C) - A. Adjust the tappet protrusion by rotating the tappet tip. Set the protrusion A so that the clearance is 0.