BMW 7 Series: Master Brake Cylinder

OVERVIEW OF BRAKE MASTER CYLINDER/BRAKE BOOSTER

Fig. 89: Overview Of Brake Master Cylinder

1. Brake booster
2. Expansion tank
3. Vacuum hose
4. Brake master cylinder
5. Bleed braking system

REMOVING AND INSTALLING/REPLACING EXPANSION TANK FOR HYDRAULIC BRAKE CONTROL

Necessary preliminary tasks

• Read and comply with GENERAL INFORMATION.
• Remove COVER FOR COWL PANEL on left

NOTE: Extract brake fluid out of expansion tank. Use a suction bottle used exclusively for drawing off brake fluid.

Do not reuse drawn out brake fluid.

Disconnect plug connection (1).

Pull out locking pin (2) and lift out expansion tank in vertical direction.

Fig. 90: Identifying Plug Connection And Locking Pin

IMPORTANT: Check rubber plugs (1) in brake master cylinder for damage and replace if necessary.

Push the expansion tank vertically onto the master brake cylinder.

Fig. 91: Identifying Rubber Plugs

REMOVING AND INSTALLING/REPLACING MASTER BRAKE CYLINDER FOR DSC

Necessary preliminary tasks

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

After completing repair work, bleed BRAKE SYSTEM WITH DSC.

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. 92: Identifying Nuts, Brake Booster And Brake Master Cylinder

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. 93: Identifying Sealing Ring

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 completion of the repair work:

• Brake pedal travel sensor adjustment.

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