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 2017 BMW 550i GT xDrive, 2017 BMW 535i GT xDrive, 2017 BMW 535i GT, 2016 BMW 550i GT xDrive, and 2016 BMW 535i GT xDrive. However, it is still accessible from the selected car via links, so may be relevant.

Special tools required:

00 9 316

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

NOTE: Use repair kit.

Check guide sleeves (5). If necessary, fit repair kit guide sleeve.

Fig 1: Identifying Rear Brake Caliper Guide Sleeves

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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: Forcing Out Piston Through Connection Bore Using Compressed Air

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Press off dust sleeve (1).

Fig 3: Identifying Dust Sleeve

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Carefully remove sealing ring (1) special tool 00 9 316 .

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 sealing ring (1).

Installation :

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

Fig 4: Removing/Installing Sealing Ring

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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.

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.

Fig 5: Fitting Dust Sleeve In Annular Groove Of Piston

Courtesy of BMW OF NORTH AMERICA, INC.