34 31 505 Removing and installing / replacing master brake cylinder for DSC

WARNING: This page is about a different car, the 2011 BMW 750xi, 2011 BMW 750Lxi, 2010 BMW 750xi, and 2010 BMW 750Lxi. However, it is still accessible from the selected car via links, so may be relevant.

Necessary preliminary tasks:

Read and comply with GENERAL INFORMATION .
Remove EXPANSION TANK .
Remove BRAKE BOOSTER .

After completing repair work, bleed BRAKE SYSTEM WITH DSC .

IMPORTANT: Before beginning work, fully press the brake pedal several times to reduce the vacuum pressure in the brake servo.

Set brake booster down on a suitable surface.

Release nuts (1) and withdraw brake master cylinder (2) from brake booster (3).

Installation note:

Replace self-locking nuts.

Tightening torque 34 31 1AZ .

Fig 1: Identifying Brake Master Cylinder, Brake Booster And Nuts

Courtesy of BMW OF NORTH AMERICA, INC.

Installation note:

Replace sealing ring (1).

When inserting the brake master cylinder into the brake servo, make sure the pushrod of the brake servo and the brake master cylinder are in perfect alignment.

Fig 2: Identifying Brake Master Cylinder Sealing Ring

Courtesy of BMW OF NORTH AMERICA, INC.

F04 only:

The brake pedal travel sensor has to be transferred when the brake master cylinder is replaced.

The following service function must be performed after completing the repair work:

Calibrate brake pedal travel sensor.