34 11 000 Removing and Installing/Replacing Brake Pads on Both Disc Brakes (2 Pistons)

34 11 000 Removing and installing/replacing brake pads on both disc brakes (2 pistons)

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 tasks:
- Remove front wheels
- Remove brake pad wear sensor







Lever out retaining spring (1) in direction of arrow towards rear.

Installation note:
Attach retaining spring first at top and bottom on brake caliper and then allow to engage in recesses of brake caliper housing.







Remove plastic plugs (1).







Unscrew guide bolts (1). Withdraw brake calliper backwards.

IMPORTANT:
Guide screws (1) are hexagon socket screws (width across flats 9).
Tie brake caliper back and do not allow to hang from brake hose.

Installation note:
Only clean guide bolts; do not grease.

Check threads.
Replace all guide screws which are not in perfect condition.
Tightening torque 34 11 4AZ.







IMPORTANT:
When forcing piston back:
- Pay attention to brake fluid level in expansion tank; brake fluid that spills over will damage paintwork.

Press back brake pads and piston with special tool 34 1 050.







IMPORTANT:
Mark any worn brake pads.
In the event of one-sided brake pad wear, do not change brake pads round.
Observe minimum thickness of brake pads.
Do not apply grease to brake lining backplate.

Remove outer brake pad (1) in direction of arrow.
Force inner brake pad (2) in direction of arrow off piston and remove.

NOTE: The inner brake pad is seated with springs in the piston or in the brake caliper housing.

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 set point value.







IMPORTANT: New brake pads may only be fitted if the brake disc thickness is greater than the minimum brake disc thickness (MIN TH).







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 surfaces (1) of brake pad T-heads/ brake caliper housing 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 pad guides (1). Instead, clean with brake cleaner and apply a thin coating of brake pad paste.







NOTE:
After completing work:
- Fully depress brake pedal several times so that brake pads contact brake discs.
- 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.
- When replacing pads, reset CBS display in accordance with factory specification.