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

WARNING: This page does not describe the selected car, but rather 18 other vehicles, including the 2015 BMW Alpina B7L xDrive, 2015 BMW Alpina B7 xDrive, 2015 BMW 750i xDrive, 2015 BMW 750Li xDrive, and 2015 BMW 740Li xDrive. However, it is still accessible from the selected car via links, so may be relevant.

Special tools required:

00 9 316

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

NOTE: Use repair kit.

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

Fig 1: Identifying 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: Removing Piston Out From Connection Bore Using Compressed Air

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Press off dust sleeve (1).

Fig 3: Identifying Piston 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 ANTI-SQUEAK/CORROSION PASTE to cylinder bore, piston and seal.

Fig 4: Removing Sealing Ring Using Special Tool (00 9 316)

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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 brake cylinder paste or brake fluid so as to ensure that the dust sleeve is perfectly seated.

Fig 5: Identifying Dust Sleeve And Piston

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