Brake Booster

Brake Booster

Special tools, testers and auxiliary items required

• Brake Charger/Bleeder Unit (VAS 5234)

Removing

- Remove the driver side trim panel.

- Remove the brake lamp switch/brake pedal switch. Refer to => [ Brake Lamp and Brake Pedal Switch ] Service and Repair.

- Remove the bracket for brake lamp switch.

- Separate the brake pedal from the brake booster. Refer to => [ Brake Pedal and Booster, Separating and Connecting ] Service and Repair.

- Remove the support on the mounting bracket through which the pressure rod of the brake booster runs.





- Remove the plenum chamber cover.

- Remove the engine compartment seal and cover strip in the area of the brake booster.

- Remove the facing wall of the plenum chamber.

- Disconnect the connector from the brake pressure sensor.

- Disconnect the connector from the brake fluid level warning switch (F34).

- Remove the ground wire from ground point on the body behind the E-box, remove the wiring harness from the retainer behind the brake booster and lay aside.

- Remove the E-box from the left plenum chamber retainer and lay as far as possible aside.





- Place sufficient lint free cloths in the plenum chamber in the area of the master cylinder.

- Extract as much brake fluid as possible from the brake fluid reservoir using the (VAS 5234) or (V.A.G 1869/4).

- Remove the brake fluid reservoir, press the engagement straps toward the outside of the reservoir and simultaneously pull the reservoir out of the sealing plugs.

- Remove the left front brake line from the retainer on the master cylinder.

- Disconnect the brake lines from the master cylinder and seal the brake lines using sealing plugs from kit (1H0 698 311 A).

- Remove the master cylinder nuts.

- Carefully remove the master cylinder from the brake booster.

- Remove the brake booster membrane position sensor. Refer to => [ Brake Booster Membrane Position Sensor ] Service and Repair.

- Remove the vacuum hose from the brake booster.

- Remove the brake lines from the triple retainer on the brake booster.

- Disconnect the left front brake line at the separating point in the left front wheel housing.

- Remove the nuts for the brake booster.





- Carefully remove the brake booster from the plenum chamber.

Installing

- Installation is performed in the reverse order of removal.

Observe the following points when installing:

Brake Pedal and Brake Booster, Connecting

- Hold the push rod ball head in front of the mount and push the brake pedal toward the brake booster until the ball head engages audibly.

- After installing, bleed the brake system. Refer to => [ Brake System Bleeding ] Service and Repair.

After bleeding the brake system, the basic setting for brake pressure sensor 1 (G201) must be performed.

(VAS 5051), connecting and selecting functions. Refer to => [ VAS 5051, Connecting and Selecting Functions ] Testing and Inspection.

- Install the brake lamp switch. Refer to => [ Brake Lamp and Brake Pedal Switch ] Service and Repair.