BMW X3 (F25) Service & Repair Manual: Master brake cylinder

OVERVIEW OF BRAKE MASTER CYLINDER/BRAKE BOOSTER

• Removing and installing/replacing expansion tank for hydraulic brake control
• Removing and installing/replacing tandem brake master cylinder for dsc

Removing and installing/replacing expansion tank for hydraulic brake control

Necessary preliminary tasks:

• Read and comply with GENERAL INFORMATION.
• Remove COWL PANEL COVER /service opening 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).

Release retaining screw (2).

Detach expansion tank (3) by pulling vertically upward.

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.

Removing and installing/replacing tandem brake master cylinder for dsc

Necessary preliminary tasks:

• Read and comply with GENERAL INFORMATION.
• Remove EXPANSION TANK.
• REMOVE left partition wall for units compartment.

After completing repair work, bleed BRAKE SYSTEM WITH DSC.

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

Undo pipes (1) and close off.

Undo nuts (2) and pull tandem brake master cylinder (3) out of the brake servo.

Installation note: Replace self-locking nuts.

Installation note: Replace sealing ring (1).

When inserting the tandem brake master cylinder, the brake servo, make sure that the pushrod of the brake servo and the tandem brake master cylinder are exactly aligned with each other.