34 31 181 Removing and installing / replacing expansion tank for hydraulic brake actuation

WARNING: This page is about a different car, the 2010 BMW M3, 2009 BMW M3, and 2008 BMW M3. 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 lower section of microfilter housing

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.

Pull off supply hose (1) of clutch hydraulic system if necessary.

Unfasten plug connection (2) and disconnect.

Unlock quick-release fastener (3) and disconnect vacuum line.

Feed brake line out of rubber grommet and remove cover (4).

Fig 1: Identifying Quick-Release Fastener, Plug Connection, Cover And Supply Hose

Courtesy of BMW OF NORTH AMERICA, INC.

Unclip locking pin (1) from retaining lugs (2) and pull out locking pin.

Pull expansion tank in direction of arrow vertically out of brake master cylinder.

Fig 2: Identifying Locking Pin And Retaining Lugs

Courtesy of BMW OF NORTH AMERICA, INC.

IMPORTANT: Check rubber plug in brake master cylinder for damage and replace if necessary.
Push the expansion tank vertically onto the master brake cylinder.

Fig 3: Identifying Expansion Tank Vertically Onto Master Brake Cylinder

Courtesy of BMW OF NORTH AMERICA, INC.

After installation:

Bleed braking system