Parking Brake System: Adjustments

34 10 014 - Adjusting handbrake





Special tools required:
- 34 6 301 34 6 300 Brake Piston Tool
- 34 6 306 34 6 300 Brake Piston Tool
- 34 6 307 34 6 300 Brake Piston Tool
- 34 6 308 34 6 300 Brake Piston Tool





Perform inspection in the following manner:

When 1st ratchet is engaged, no braking force should be exerted.

The difference in wheel circumferential forces between the left and right wheels may deviate by max. 30 % from the greater value (measured on brake analyzer).

In event of larger deviations of wheel circumferential force: readjust parking brake.

Braking with locked wheels must be possible with the parking brake.

The parking brake must be reset if the actuation stroke is greater than 6 teeth.





Note:
Accurate adjustment of the parking brake is only possible if the parking brake Bowden cables and all moving parts on the parking brake move easily and function correctly.

Basic setting of the parking brake is required:

- When replacing rear wheel brake pads.
- When replacing brake discs.
- In event of excessive actuation stroke (6 teeth).
- When replacing parking brake Bowden cables
- When replacing parking brake lever





Setting instruction for parking brake Bowden cables

Release gaiter (1) of parking brake lever from clip.

Release self-locking nut (2) until the load on the Bowden cable has been relieved completely.





Remove rear brake pads Removing and Installing/Replacing Brake Pads on Both Rear Disc Brakes

Insert brake piston into brake caliper with special tools 34 6 301 34 6 300 Brake Piston Tool, 34 6 306 34 6 300 Brake Piston Tool, 34 6 307 34 6 300 Brake Piston Tool, 34 6 308 34 6 300 Brake Piston Tool.

Install brake pads.





Screw in adjusting nut on parking brake lever until a gap (3) of 2-3 mm between parking brake actuating lever (2) and notched pin (1) is set at brake calipers.





Important!
Observe following sequence:

1. Release adjusting nut on parking brake lever completely.
2. Remove brake pads.
3. Insert brake piston into brake caliper.
4. Install brake pads.
5. Adjust adjusting nut on parking brake lever as shown above.
6. Apply parking brake lever three times.
7. Press brake pedal to floor at least three times so that air gap can be set.
8. Carry out operational check



Checking adjustment on brake analyzer
0th tooth (parking brake released): -
Vehicles with manual transmission: Shift lever in neutral position.
Vehicles with automatic transmission: Selector lever position "N" wheel circumferential force ≤100 N.
1st tooth: - No braking force increase with regard to the 0th tooth. Indicator lamp can be lit.
2nd tooth: - An increase in braking force must take place. Indicator lamp must be lit.
3rd tooth: - Increase in braking force.
4th tooth: - Wheel circumferential force per wheel: 700 N to 1300 N.
(Must be achieved in the 4th tooth at the latest)