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

Necessary preliminary tasks:

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 1: Identifying Hydraulic Brake Control Plug Connection And Locking Pin

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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 2: Identifying Brake Master Cylinder Rubber Plugs

Courtesy of BMW OF NORTH AMERICA, INC.