34 21 200 Removing And Installing Or Replacing Brake Linings On Both Rear Disc Brakes
Special tools required:
- 34 1 050
- 34 1 080
- 34 1 280
Necessary preliminary tasks:
- Remove wheels.
- Remove brake pad wear sensor .
Observe safety instructions on raising the vehicle. See 00...... LIFTING VEHICLE WITH A LIFTING PLATFORM .
If necessary, when replacing linings, reset CBS display in accordance with factory specification.
- Fully depress brake pedal several times so that brake linings contact brake discs.
- When installing new brake linings at front and rear axles, brake fluid level must be brought up to "MAX" marking.
- Read and comply with notes on breaking in new brake discs/ brake pads.
The fault memory entry must be deleted. The vacuum pressure sensor only has to be replaced if the fault is entered repeatedly.
Remove plastic plugs (1).
Right side:
Disconnect plug connection for brake lining wear sensor.
If necessary, replace brake lining wear sensor.
Release guide screws (2) with special tool 34 1 080.
Installation:
Only clean guide screws; do not grease.
Check threads.
Replace all guide screws which are not in perfect condition.
Lift out retaining spring (3).
Withdraw brake caliper backwards.
Turn piston fully back with special tool 34 1 050.
- Pay attention to brake fluid level in expansion tank; brake fluid that spills over will damage paintwork.
Remove outer brake lining.
Inner brake lining is located with its spring in the piston.
If the brake linings are worn on one side, they must not be mixed up!
Observe minimum thickness of brake linings.
Clean brake linings.
Do not apply grease to brake pad backplate.
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.
New brake linings may only be installed if the brake disc thickness is greater than or equal to the minimum brake disc thickness (MIN TH).
Check dust sleeve (1) for damage and replace if necessary.
Clean contact face (2) of brake piston and apply a thin coating of anti-squeak compound.
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 mounting faces (1) and (2) of brake lining hammer heads/brake caliper housing and coat with anti-squeak compound.
Clean contact face (3) of brake caliper and apply a thin coating of anti-squeak compound.
Clean brake caliper mounting bracket at hammer head guides and apply a thin coating of anti-squeak compound.