Examination
1. Press the brake pedal several times with the engine off to create equal pressure in the cavities of the vacuum booster (close to atmospheric).
2. At the same time, by the force applied to the pedal, determine if the valve body is sticking.
3. Stop the brake pedal in the middle of its travel and start the engine. With a working vacuum booster, the brake pedal should go forward after starting the engine. If the pedal does not move forward, check the attachment of the hose tip, the condition of the attachment flange of the tip in the amplifier, the condition of the hose and fitting.
4. On vehicles with diesel engines, also check the operation of the vacuum pump.
Removing
1. Remove the master brake cylinder.
2. Loosen the clamp and disconnect the vacuum hose from the brake booster one-way valve. In the passenger compartment, remove the cover of the fuse box.
3. Disconnect the electrical connector from the key block, unscrew the fastening screws and remove the lower trim of the instrument panel. Remove the mounting bracket and remove the pin with a head and a hole for the cotter pin that secures the brake pedal pusher to the vacuum brake booster.
4. Unscrew the nuts securing the vacuum booster to the bulkhead of the engine compartment, remove it.
Installation
1. Before installing the vacuum booster, measure the distance from the end of the pusher of the vacuum booster to the mating surface of the master brake cylinder, which should be 22.3±0.1 mm.
2. Make sure the gasket is properly installed on the back of the vacuum booster, then install the vacuum booster in the engine compartment.
3. Check that the pusher is correctly aligned with the brake pedal, then screw on the vacuum booster mounting nuts and tighten them to the required torque.
4. Align the pedal with the pusher, insert the pin with the head and the hole for the cotter pin and secure with the fastening brackets. Install the lower instrument panel trim.
5. Connect the vacuum hose to the one-way valve and secure with a hose clamp.
6. Install the master cylinder and bleed the air from the brake system.