34 00 014 Adjusting Parking brake
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 can only be set correctly 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.
- In event of excessive actuation stroke (8 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 0.15-2.5 mm between parking brake lever (2) and stop (1) is set at brake calipers.
As a result of the current driving, the gap (A) may change and differ from the aforementioned dimensions.
Observe following sequence:
- Release adjusting nut on parking brake lever completely.
- Remove rear brake pads and screw brake piston into the brake caliper in accordance with the repair instructions.
- Adjust adjusting nut on parking brake lever as shown above.
- Apply parking brake lever three times.
- Press brake pedal to floor at least three times so that air gap can be set.
- Carry out function check
1. Check by hand on the vehicle lift
- 0th tooth
(parking brake released): Both wheels must turn freely
- 1st tooth:
Both wheels must turn freely. No increase in braking effect compared with 0th tooth permitted → carry out new basic setting if there is a braking effect.
- 2nd tooth:
An increase in braking force can occur. Indicator lamp must be lit.
- 3rd tooth:
Increase in braking force
- 4.-6. Tooth:
Wheel circumferential force per wheel: 600 Nm to 1200 Nm (must be reached with the 6th tooth at the latest).
- Check of the setting on the brake test stand
- 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 ≤120 N.
- 1st tooth:
No brake force increase with regard to the 0th tooth. Indicator light may light up.
- 2nd tooth:
An increase in braking force can occur. Indicator lamp must be lit.
- 3rd tooth:
Increase in braking force.
- 4.-6. Tooth:
Wheel circumferential force per wheel: 600 N to 1200 N.
(Must be achieved in the 6th tooth at the latest)
Re-adjustment of the parking brake.
- Excessive operating travel (greater than 6 teeth, less than 8 teeth).
- Brake values outside the specifications.
→ Carry out new basic setting
→ Repeat check of setting on the brake test stand
- Check of the setting on the brake test stand
- 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 ≤120 N.
- 1st tooth:
No brake force increase with regard to the 0th tooth. Indicator light may light up.
- 2nd tooth:
An increase in braking force can occur. Indicator lamp must be lit.
- 3rd tooth:
Increase in braking force.
- 4.-6. Tooth:
Wheel circumferential force per wheel: 600 N to 1200 N.
(Must be achieved in the 6th tooth at the latest)