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

Special tools required: 

• 32 1 270

Necessary preliminary tasks: 

• Remove expansion tank, refer to 34 31 181 REMOVING AND INSTALLING / REPLACING EXPANSION TANK FOR HYDRAULIC BRAKE ACTUATION .
• Remove footwell trim.
• Read and comply with General Information, refer to 34 00 ... GENERAL INFORMATION .

After completing tasks, bleed brake system with DSC, refer to 34 00 050 BLEEDING BRAKE SYSTEM WITH DSC .

Remove locking clip (1) and disengage and pull out locking pin. Slacken nuts (2).

Fig 1: Removing Locking Clip

Courtesy of BMW OF NORTH AMERICA, INC.

Installation: 

Replace self-locking nuts. Tightening torque, refer to 35 11 1AZ in BRAKES - TIGHTENING TORQUES - 645CI .

Unfasten brake lines (1). Detach brake lines at junction (2) and remove short sections. Seal off brake lines and brake master cylinder with plugs 32 1 270

Fig 2: Detaching Brake Lines At Junction

Courtesy of BMW OF NORTH AMERICA, INC.

Installation: 

1. Fit lines at both connection points and then tighten down. Tightening torque, refer to 34 32 1AZ in BRAKES - TIGHTENING TORQUES - 645CI .

Release nuts (3) and feed brake master cylinder out of brake booster.

Installation: 

1. Replace self-locking nuts. Tightening torque, refer to 34 31 1AZ in BRAKES - TIGHTENING TORQUES - 645CI .

Installation: 

1. Replace sealing ring.

Fig 3: Replacing Sealing Ring

Courtesy of BMW OF NORTH AMERICA, INC.

Installation: 

When inserting the brake master cylinder (2) into the brake booster (1), make sure the pressure rod of the brake booster and that of the brake master cylinder meet each other on one level.

Fig 4: identifying Brake Master Cylinder (2) And Brake Booster (1)

Courtesy of BMW OF NORTH AMERICA, INC.