Parking Brake System: Adjustments

34 10 014 Adjusting handbrake

Special tools required:







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 test stand).
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:
- In event of excessive actuation stroke (6 teeth).
- When replacing parking brake Bowden cables
- When replacing parking brake lever







Adjusting instructions for parking brake Bowden cables
Release the gaiter (1) of the parking brake lever from the clips.
Release self-locking nut (2) until the load on the Bowden cable has been relieved completely.







Screw in adjusting nut on parking brake lever until a gap (A) of 0.5-1.5 mm between parking brake lever (2) and stop (1) is set at brake calipers.







IMPORTANT:
Observe following sequence:
1. Release adjusting nut on parking brake lever completely.
2. Adjust adjusting nut on parking brake lever as shown above.
3. Apply parking brake lever three times.
4. Press brake pedal to floor at least three times so that air gap can be set.
5. Carry out function check

Checking adjustment on brake test stand

0th tooth (parking brake firmly unloaded):

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 brake force increase with regard to the 0th tooth. Indicator light may light up.
2nd Tooth: No brake force increase with regard to the 0th tooth. Indicator light may light up.
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)