34 21 200 Removing and installing/replacing both rear brake pads of disc brake
Special tools required:
Attention!
- Brake pad wear sensor: After removal it must be replaced (brake pad wear sensor loses its retention capability in the break pad) .
- Retaining pins and expanding spring: for vehicles older than 48 months it is recommended to replace the retaining spring!
So as not to damage the surface coating, if possible do not mechanically clean the guide surfaces for the brake pads on the brake caliper mounting bracket, but rather clean with brake cleaner BMW TI. number 83 19 2 154 780 and apply a thin coating of break pad paste BMW TI. number 83 19 2 158 851 (3 gr.) or 83 19 2 158 852 (100 gr.) .
Spread brake pad paste onto the marked surfaces using a brush!
Observe GUIDELINE FOR APPLYING BRAKE PAD PASTE ON BRAKE PADS AND BRAKE ANCHOR PLATE !
Necessary preliminary tasks:
- Remove WHEELS .
- Remove BRAKE PAD WEAR SENSOR .
- Fully depress brake pedal several times so that brake pads contact brake discs.
- When installing new brake pads at front and rear axles, the brake fluid level must be brought up to "Max." marking.
- Read and comply with notes on BREAKING IN NEW BRAKE DISCS/BRAKE PADS .
- If necessary, when replacing brake pads, reset CBS display as per factory specification.
Lift out retaining spring (1).
Remove cover plug (1).
Unscrew guide bolts (1).
Withdraw brake caliper backwards.
Attention!
Tie brake caliper back and do not allow to hang from brake hose.
Installation note:
Tightening torque 34 21 4AZ .
Clean guide screws only; do not grease.
Check threads.
Replace all guide screws which are not in perfect condition.
Attention!
When pressing down piston, note brake fluid level in expansion tank.
Overflowing brake fluid will damage the paintwork.
Turn piston back fully with special tool 34 1 050 .
Attention!
Mark any worn brake pads.
In the event of one-sided brake pad wear, do not change brake pads round.
Remove outer brake pad.
Inner brake pad is located with its spring in the piston.
Clean brake pads.
Do not grease backs of brake pads sleeve.
Check minimum brake disc thickness:
- Position special tool 34 1 280 at three measuring points in area (1) and measure.
- Compare measuring result and lowest value with SETPOINT VALUE .
Attention!
New brake pads may only be installed if the brake disk thickness is greater than the minimum brake disc thickness.
Attention!
If new brake pads are mounted on a brake disc, the following must be observed:
- Bevel edges in the area (1) slightly (dimension A must not exceed maximum 1 mm).
These procedures applies for all the following described brake systems.
Check dust boot for damage and replace if necessary.
Clean contact surface (1) of brake piston with brake cleaner and apply a thin coating of brake pad paste.
Attention!
Dust boot must not come into contact with brake pad paste as this may cause the dust boot to swell.
Clean contact surfaces (1) of T-heads/brake caliper housing with brake cleaner and apply a thin coating of brake pad paste.
Clean contact surface (1) of brake caliper with brake cleaner and apply a thin coating of brake pad paste.
So as not to damage the surface coating, if possible do not mechanically clean the guide surfaces (1) for the brake pads on the brake caliper mounting bracket. Clean guide surfaces (1) with brake cleaner and apply a thin coating of brake pad paste.
So as not to damage the surface coating, if possible do not mechanically clean the guide surfaces (1 and 2) for the brake pads on the brake caliper mounting bracket. Clean guide surfaces (1 and 2) with brake cleaner and apply a thin coating of brake pad paste.
Lightly coat the T-head of the inner brake pad with brake pad paste in area (1 and 2).
Lightly coat the T-head of the outer brake pad with brake pad paste in area (1 and 2).