34 21 812 Overhauling left or right rear brake caliper (brake caliper removed)

WARNING: This page does not describe the selected car, but rather 21 other vehicles, including the 2013 BMW 328xi, 2013 BMW 328i, 2012 BMW 328xi, 2012 BMW 328i, and 2011 BMW 328xi. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: In the following work step, large forces occur at the brake caliper piston (up to more than 2800 N). Risk of injury!

Check guide sleeves (5), fitting repair-kit guide sleeve if necessary.

Fig 1: Check Guide Sleeves (5), Fitting Repair-Kit Guide Sleeve If Necessary

Courtesy of BMW OF NORTH AMERICA, INC.

Carefully force piston out through connection bore with compressed air. To protect piston, place a protective plate (e.g. hard wood or hard felt) in caliper recess. Do not grip piston with fingers - risk of trapping!

Fig 2: Carefully Force Piston Out Through Connection Bore

Courtesy of BMW OF NORTH AMERICA, INC.

Press off dust sleeve.

Carefully remove sealing ring (1) special tool Sealing lip wedge 00 9 316 in set 00 9 310 ASSEMBLY WEDGES (SET IN PLASTIC CASE) . Clean cylinder bores and parts with alcohol and dry with compressed air. Thoroughly inspect cylinder bore, piston and flange surfaces. Machining of cylinders and pistons is not permitted. Install new seal.

Fig 3: Carefully Remove Sealing Ring (1) Special Tool 00 9 316

Courtesy of BMW OF NORTH AMERICA, INC.

Installation: Apply a light coat of Ate brake cylinder paste to cylinder bore, piston and seal.

Fit dust sleeve (1) in annular groove of piston (2). Press piston into cylinder bore.

IMPORTANT: Do not twist brake piston.

Evenly press dust sleeve (1) onto brake caliper housing as far as it will go.

Fig 4: Fit Dust Sleeve (1) In Annular Groove Of Piston

Courtesy of BMW OF NORTH AMERICA, INC.

Installation: The area between the dust sleeve and the brake caliper housing must be kept dry. It must not come into contact with Ate brake cylinder paste or brake fluid so as to ensure that the dust sleeve is perfectly seated.