34 31 181 Removing And Installing / Replacing Expansion Tank For Hydraulic Brake Actuation

WARNING: This page is about a different car, the 2010 BMW M5, 2009 BMW M5, 2008 BMW M5, 2007 BMW M5, and 2006 BMW M5. However, it is still accessible from the selected car via links, so may be relevant.

Necessary preliminary tasks:

Remove lower section of microfilter housing. See 64 31 061 REMOVING AND INSTALLING/REPLACING LEFT OR RIGHT MICROFILTER HOUSING LOWER SECTION .
Read and comply with General Information .

Suck the brake fluid out of the expansion tank. Use suction bottle exclusively to draw off brake fluid.

IMPORTANT: Do not reuse drawn out brake fluid.

Fig 1: Identifying Expansion Tank

Courtesy of BMW OF NORTH AMERICA, INC.

Unfasten plug connection (1) and disconnect.

Release retaining screw (2).

Installation:

Tighten to specified torque 34 31 3AZ .

Pull expansion tank vertically out of brake master cylinder.

Fig 2: Identifying Plug Connection And Screw

Courtesy of BMW OF NORTH AMERICA, INC.

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: Pushing Expansion Tank Vertically Onto Master Brake Cylinder

Courtesy of BMW OF NORTH AMERICA, INC.