34 21 200 Removing and Installing/Replacing Both Rear Disc Brakes
34 21 200 Removing And Installing/Replacing Brake Pads Of Both Rear Disc Brakes
Special tools required:
IMPORTANT:
- Brake pad wear sensor: after removal it must be replaced (brake pad wear sensor loses its retention capability in the break pad).
- Retaining 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.
Instead, clean with brake cleaner BMW part no. 83 19 2 154 780 and apply a thin coating of brake pad paste BMW part no. 83 19 2 158 851.
Necessary preliminary work:
- Remove wheels.
- Remove brake pad wear sensor
Detach retaining clip (1) in direction of arrow.
Disengage parking brake Bowden cable (2) from operating lever (3) at brake caliper.
Feed out parking brake Bowden cable (2) downwards.
IMPORTANT:
Both guide bolts must be released and then the brake caliper detached towards the rear.
The springs may be bent when only one bolt is released and the brake caliper is folded up.
Unscrew guide bolts (1).
If necessary, grip at hexagon head (2).
Installation note:
Replace guide bolts.
Tightening torque 34 21 3AZ. 00 00 Excerpt From Company Standard BMW GS 90003-2
IMPORTANT:
Mark any worn brake pads.
In the event of one-sided brake pad wear, do not change brake pads round.
Remove brake pads (1) in direction of arrow from brake anchor plate.
Observe minimum thickness of brake pads.
Clean brake pads.
Do not apply grease to brake lining backplate.
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.
IMPORTANT: New brake pads may only be fitted if the brake disk thickness is greater than the minimum brake disc thickness (MIN TH).
IMPORTANT:
When pressing piston back, note brake fluid level in expansion tank.
Overflowing brake fluid will damage the paintwork.
Screw brake piston with special tools 34 6 309, 34 6 306, 34 6 307, 34 6 308 into brake caliper.
IMPORTANT: Dust boot must not come into contact with brake pad paste as this may cause the dust boot to swell.
Check dust boot (1) for damage and replace if necessary.
Clean contact surface (2) of brake piston 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.
IMPORTANT: Brake pad with indentation (1) is intended for accommodating the brake pad wear sensor and must be fitted on the piston side.
So as not to damage the surface coating, if possible do not mechanically clean pad guides (1). Instead, clean with brake cleaner and apply a thin coating of brake pad paste.
IMPORTANT:
After completing work:
- When installing new brake pads at front and rear axles, brake fluid level must be brought up to "MAX" marking.
- Read and comply with notes on braking in new brake discs / brake pads.
- Fully depress brake pedal several times so that brake pads contact brake discs.
- If necessary, when replacing pads, reset CBS display in accordance with factory specification.
Replacement:
Remove lining springs (1) and replace.
Installation note:
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.
Instead, clean with brake cleaner and apply a thin coating of brake pad paste.