34 21 812 Overhauling Left Or Right Rear Brake Caliper (Brake Caliper Removed)

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2008 BMW 750i, 2008 BMW 750Li, 2007 BMW 750i, 2007 BMW 750Li, and 2006 BMW 750i. However, it is still accessible from the selected car via links, so may be relevant.

Special tools required:

34 1 132

NOTE: Use original BMW repair kit.

Take off plastic caps (1).

Unscrew guide screws (2).

Installation:

Only clean guide screws; do not grease. Check guide bolts, replace if necessary.

Tightening torque: 34 21 5AZ. See 34 21 REAR BRAKE

Fig 1: Identifying Plastic Caps & Guide Screws

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Dismantle brake caliper and remove brake linings.

Installation:

Press brake lining fully outwards and insert spring (4).

Fig 2: Identifying Brake Linings

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WARNING: Danger of injury!

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

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 3: Locating Brake Caliper Piston

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

Fig 4: Identifying Guide Sleeve

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Remove sealing ring carefully with a plastic needle.

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.

Fig 5: Removing Sealing Ring

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Installation:

Apply a light coat of Ate brake cylinder paste to cylinder bore, piston and sealing sleeve, Refer to BRAKES - OPERATING FLUIDS .

Install sealing cover in rear annular groove of cylinder bore.

Press in piston with a hardwood board.

IMPORTANT: Do not tilt piston.

Fig 6: Installing Sealing Cover In Rear Annular Groove Of Cylinder

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Press on dust protection sleeve evenly up to stop with special tool 34 1 132 .

Installation:

The area between dust protection sleeve and brake caliper housing must be kept dry so as to ensure correct seating for the dust protection sleeve.

Keep Ate brake cylinder paste or brake fluid away from this area.

Make sure dust protection sleeve is correctly seated on piston.

Fig 7: Identifying Special Tool (34 1 132)

Courtesy of BMW OF NORTH AMERICA, INC.