34 21 320 Removing and installing or replacing both rear brake discs

Special tools required:

34 1 280

Necessary preliminary tasks

Remove WHEELS .
Remove and clean BRAKE PADS

After completing work:

Adjusting PARKING BRAKE
Read and comply with notes on BREAKING IN NEW BRAKE DISCS/BRAKE PADS .

Check minimum brake disc thickness:

Position special tool 34 1 280 at three measuring points in area (1) and measure.
Compare measurement result and lowest value with SETPOINT VALUE .

New brake pads may only be fitted if the brake disc thickness is greater than the MINIMUM BRAKE DISC THICKNESS (MIN TH).

If the brake discs are replaced, you must also fit new brake pads.

Fig 1: Checking Minimum Brake Disc Thickness

Courtesy of BMW OF NORTH AMERICA, INC.

Always replace brake discs in pairs.

Release bolts (1) and detach brake anchor plate.

Installation note:

Tightening torque 34 21 2AZ .

Fig 2: Identifying Brake Anchor Plate And Bolts

Courtesy of BMW OF NORTH AMERICA, INC.

IMPORTANT: To release brake disc: Do not under any circumstances strike friction ring with a hammer or similar!
If necessary, carefully tap on base of brake disc chamber with a rubber mallet.
Clean contact surface of brake disc at wheel hub thoroughly and remove traces of corrosion.
Unevenness on contact surface may result in distortion of brake disc!

IMPORTANT: Brake discs must not be mixed up (directional ventilation).

Release screws (1) and remove brake disc.

Installation note:

Replace screw.

Tightening torque 34 21 1AZ .

Fig 3: Identifying Brake Disc Screws

Courtesy of BMW OF NORTH AMERICA, INC.