34 21 320 Removing and installing/replacing both brake discs

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2013 BMW 128i, 2012 BMW 128i, 2011 BMW 128i, 2010 BMW 128i, and 2009 BMW 128i. However, it is still accessible from the selected car via links, so may be relevant.

Special tools required:

34 1 280

See BRAKES - SPECIAL TOOLS

Necessary preliminary tasks:

Remove wheels . See WHEELS .
Remove and clean 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.

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

Always replace brake discs in pairs.

Fig 1: Measuring Minimum Brake Disc Thickness

Courtesy of BMW OF NORTH AMERICA, INC.

IMPORTANT: New brake pads may only be installed if the brake disc thickness is greater than or equal to the minimum brake disc thickness (MIN TH) (not incl. M vehicles).
In the case of M vehicles and perforated brake discs, new brake pads may only be installed if the brake disc thickness is greater than the minimum brake disc thickness (MIN TH).

See BRAKES - TECHNICAL DATA .

NOTE: The minimum brake disc thickness is configured in such a way that it lasts the life of a further set of brake pads (does not apply to M vehicles and perforated brake discs).

Release bolts (1) and detach brake anchor plate.

Installation:

Replace screws.

Tightening torque, see 34 21 REAR BRAKE .

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!

Fig 3: Identifying Brake Disc And Screw

Courtesy of BMW OF NORTH AMERICA, INC.

Release screw (1) and remove brake disc (2).

Installation:

Replace screw.

Tightening torque, see 34 21 REAR BRAKE .

After installation:

Adjusting parking brake
Read and comply with notes on braking in new brake discs / brake pads .