Overhauling Left or Right Rear Brake Caliper (Brake Caliper Removed)

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





Special tools required:
- 34 1 132 34 1 130 Installation Sleeves





Note:
Use original BMW repair kit.





Take off plastic caps (1).

Unscrew guide screws (2).

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

Tightening torque: 34 21 5AZ 34 21 Rear Brake.





Dismantle brake caliper and remove brake linings.

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





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!





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





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.





Installation Note:
Apply a light coat of Ate brake cylinder paste to cylinder bore, piston and sealing sleeve,

Refer to BMW Service Operating Fluids.

Install sealing cover in rear annular groove of cylinder bore.

Press in piston with a hardwood board.

Important!
Do not tilt piston.





Press on dust protection sleeve evenly up to stop with special tool 34 1 132 34 1 130 Installation Sleeves.

Installation Note:
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.