Overhauling brake caliper, front
WARNING:
Vehicle may slip off the vehicle hoist if the vehicle hoist is handled incorrectly.
Danger! Immobilization period-threatening injuries!
Danger! Immobilization period-threatening injuries!
- Observe safety instructions on raising the vehicle using a vehicle hoist.
- For additional information see: RAISING THE VEHICLE WITH A VEHICLE LIFT .
NOTE:
TECHNICAL INFORMATION
General information on changing the brake pads:
For vehicles older than 48 months it is recommended to replace the retaining spring or expanding spring.
The brake pad wear sensor must be replaced once it has been removed because the brake pad wear sensor loses its retention capability in the brake pad.
A CBS reset must be done after every brake pad exchange:
A CBS reset in the vehicle is possible in the event of a partially ground down brake pad wear sensor. The CBS display in the Central Information Display (CID) is active.
In the event of a brake pad wear sensor that is not partially ground down , a CBS reset is only possible with the diagnostic system. No CBS display in the Central Information Display (CID).
If adhesive bonded brake pads are installed, the brake pads must be replaced after releasing the adhesive bond!
General information on changing the brake pads:
For vehicles older than 48 months it is recommended to replace the retaining spring or expanding spring.
The brake pad wear sensor must be replaced once it has been removed because the brake pad wear sensor loses its retention capability in the brake pad.
A CBS reset must be done after every brake pad exchange:
A CBS reset in the vehicle is possible in the event of a partially ground down brake pad wear sensor. The CBS display in the Central Information Display (CID) is active.
In the event of a brake pad wear sensor that is not partially ground down , a CBS reset is only possible with the diagnostic system. No CBS display in the Central Information Display (CID).
If adhesive bonded brake pads are installed, the brake pads must be replaced after releasing the adhesive bond!
NOTE:
TECHNICAL INFORMATION
To prevent damage to the surface coating: With floating calipers on the brake caliper mounting bracket or with fixed calipers in the brake caliper housing, do not clean the contact surfaces for the brake pads to the extent that it is possible.
Clean the contact surfaces with brake cleaner (BMW part number 83 19 2 154 780). Next, apply a thin coat of brake pad paste (BMW part number 83 19 2 158 851 for 3 g, or 83 19 2 158 852 for 100 g).
Spread brake pad paste on the marked surfaces with a brush.
For additional information see: GUIDELINE FOR APPLYING BRAKE PAD PASTE ON BRAKE PADS AND BRAKE ANCHOR PLATE .
To prevent damage to the surface coating: With floating calipers on the brake caliper mounting bracket or with fixed calipers in the brake caliper housing, do not clean the contact surfaces for the brake pads to the extent that it is possible.
Clean the contact surfaces with brake cleaner (BMW part number 83 19 2 154 780). Next, apply a thin coat of brake pad paste (BMW part number 83 19 2 158 851 for 3 g, or 83 19 2 158 852 for 100 g).
Spread brake pad paste on the marked surfaces with a brush.
For additional information see: GUIDELINE FOR APPLYING BRAKE PAD PASTE ON BRAKE PADS AND BRAKE ANCHOR PLATE .
Preliminary work
- Refer to REMOVING THE FRONT LEFT AND RIGHT WHEELS .
- Refer to REMOVING BRAKE PAD WEAR SENSOR TO THE FRONT .
- Refer to REMOVING FRONT BRAKE PADS (BRAKE HIGH) .
- Refer to MEASURING THE MINIMUM BRAKE DISC THICKNESS (FRONT BRAKE) .
- Refer to REMOVING THE FRONT BRAKE CALIPER (BRAKING SYSTEM REMAINS CLOSED) .
- Do not grip brake piston (2) with fingers - pinch hazard!
- Push out all brake pistons (1) where dimension A=20 mm.
- To protect the brake piston, place a protective plate (1) (for example, made out of hardwood or rubber) in the brake caliper housing.
NOTE:
The description is provided only at one component. The procedure is the same for all other components.
- Press the dust boot (1) shut.
- Clean the brake pistons (1) and dry with compressed air.
- Check brake pistons (1)
and the flange surfaces for damage. If necessary, replace the brake caliper.
Work on cylinders and brake pistons that removes material is not permitted.
- Place the dust boot (1) on the brake piston (3) .
- Press the dust boot (1) in evenly in the arrow direction into the brake caliper housing.
- To ensure that the dust boot fits perfectly: keep the area between the dust boot and brake caliper housing dry.
The area between the dust boot and the brake caliper housing must not come in contact with the lubricating grease or brake fluid.
- Ensure that the dust boot is inserted in the annular groove (1) and in the brake caliper housing (2) correctly.
Follow-up work
- Refer to INSTALLING THE FRONT BRAKE CALIPER (BRAKING SYSTEM REMAINS CLOSED) .
- Refer to GREASE BRAKE PADS, BRAKE ANCHOR PLATE AND BRAKE CALIPER WITH BRAKE PAD PASTE (BRAKE HIGH) .
- Refer to INSTALLING FRONT PADS (HIGH BRAKE) .
- Refer to ADHESION OF BRAKE PADS TO BRAKE PISTONS .
- Refer to INSTALLING THE FRONT BRAKE PAD WEAR SENSOR .
- Refer to INSTALLING THE FRONT LEFT AND RIGHT WHEELS .
- Refer to COMMISSIONING OR BEDDING IN (BRAKE) OF NEW BRAKE PADS AND DISCS (HIGH BRAKE) .