Vacuum Brake Booster: Service and Repair

34 33 505 - Removing and installing or replacing brake booster





Necessary preliminary tasks:
- Read and comply with General Information Service and Repair.
- Remove brake master cylinder 34 31 505 Removing and Installing/Replacing Master Brake Cylinder for DSC
- Remove left suspension cross-brace 51 71 371 Removing and Installing/Replacing Tension Strut on Left or Right Spring Strut Dome
- Disconnect battery negative lead 61 20 900 Disconnecting and Connecting Battery Negative Lead
- Remove trim panel 51 45 184 Removing and Installing/Replacing Panel For Pedals for pedal assembly
- Remove clutch master cylinder Service and Repair from bearing block (clutch hydraulic system remains closed)





Release brake lines (1) and remove.

Installation:
Tightening torque 34 32 1AZ 34 32 Brake Lines.

Remove non-return valve (2) in direction of arrow from brake booster.

Installation:
Check rubber seal in brake booster and replace if necessary.





Disconnect plug connection (1).
Release screw (2) and swing out battery terminal.





Disconnect plug connection (1).
Unhinge the recoil spring (2).
Remove retaining clip (3).

Installation:
Replace locking clip (3).
Locking clip (3) must be seated with both legs in the pin groove.

Release screws (4).

Installation:
Tightening torque 35 11 1AZ 35 11 Pedal Assembly Console.





Move brake booster a little towards engine compartment.
Feed piston rod (1) by turning bearing block out of retaining lug (2).

Installation:
Feed brake pedal in depressed position into piston rod, moving the brake booster a little towards the engine compartment.

Remove mounting block.

Important!
Do not use any force when removing and installing the brake unit; the brake unit can be damaged under certain circumstances.
Brake lines must not be bent.





Carefully pull brake booster (1) out of bulkhead and tilt out.