34 33 505 Removing and installing or replacing brake booster

Necessary preliminary tasks:

Read and comply with GENERAL INFORMATION .
Remove BRAKE MASTER CYLINDER
Disconnect BATTERY NEGATIVE LEAD
Remove TRIM PANEL for pedal assembly

Release brake lines (1) and remove.

Installation:

Tightening torque 34 32 1AZ .

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

Installation:

Check rubber seal in brake booster and replace if necessary.

Fig 1: Removing Non-Return Valve From Brake Booster

Courtesy of BMW OF NORTH AMERICA, INC.

Disconnect plug connection (1).

Release screw (2) and swing out battery terminal.

Fig 2: Removing Battery Terminal Plug Connection And Screw

Courtesy of BMW OF NORTH AMERICA, INC.

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.

Unscrew nuts (4).

Installation:

Tightening torque 35 11 1AZ .

Fig 3: Identifying Plug Connection, Recoil Spring, Locking Clip And Nuts

Courtesy of BMW OF NORTH AMERICA, INC.

Move brake booster a little towards engine compartment.

Feed piston rod (1) by turning bearing support 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 bearing support.

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.

Fig 4: Removing Piston Rod Out Of Retaining Lug

Courtesy of BMW OF NORTH AMERICA, INC.

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

Fig 5: Identifying Brake Booster

Courtesy of BMW OF NORTH AMERICA, INC.