34 41 006 Adjusting parking brake

Parking brake must be tested on roller dynamometer as follows.

Release Wheel circumferential force +/- 300 N position:

1st tooth: Do not allow braking force to increase relative to release setting.

Indicator lamp can be lit.

2nd tooth: Braking action can begin, Indicator lamp must be lit.

3rd tooth: Braking action must begin,

4th tooth: Increasing braking action,

5th tooth: Wheel circumferential force must be at least 1100 N at one of the two rear wheels and at least 1000 N at the other wheel.

1. Wheel circumferential force differential (left to right) max. 30 % from highest value (shortly before wheel lockup).

A readjustment must be carried out in event of larger deviations of wheel circumferential force.

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

Basic setting of the parking brake is required whenever:

Brake shoes are replaced

Brake disks are replaced

Bowden cable is replaced

Bowden cable guide tube is replaced

Adjusting unit is reset

Actuating stroke is excessive

1. Adjustment specification for brake shoes

   Completely untighten adjusting nut on left Bowden cable.

   Fig 1: Adjusting Brake Shoe

   

   Completely unscrew one wheel stud on each rear wheel.

   Rotate wheel until threaded bore on right wheel reaches 7 o'clock and left wheel reaches 5 o'clock setting.

   Installation: 

   Install and tighten wheel bolt.

   Tightening torque, 36 10 1AZ.

   Fig 2: Unscrewing Wheel Stud On Each Rear Wheel

   

   Turn adjusting screw with a screwdriver until it is no longer possible to turn the wheel.

   Then unfasten the adjusting screw 8 notches.

   Fig 3: Turning Adjusting Screw

   
2. Adjustment specification for Bowden cable (E38):
   1. 2.1 Completely unfasten parking brake pedal.
   2. 2.2 Adjust nut on left Bowden cable until it is just possible to keep turning the rear wheels.
   3. 2.3 Press parking brake pedal 10 times uniformly down to 6th ratchet.
   4. 2.4 Engage parking brake pedal on 3rd ratchet.
   5. 2.5 Unfasten adjusting nut until it is still just possible to turn the rear wheels by hand.
   6. 2.6 Check wheel brake force:
   7. 1st gear wheel (can be turned by hand), 4th gear wheel fixed (cannot be turned by hand)
3. Braking in of duo-servo parking brake (E38)
   1. 3.1 On roller dynamometer: 
      1. 3.1.1 Press parking brake pedal fully until wheel circumferential force at both wheels is min. 800 N.
      2. 3.1.2 Release parking brake pedal after approx. 2 minutes.
   2. 3.2 When road driving  (if possible on company property or an unused road):
      1. 3.2.1 At approx. 40 km/h, press parking brake pedal until a braking effect can be felt (disengaged or selector lever position "N" for automatic vehicles).
      2. 3.2.2 Press parking brake pedal into next catch and continue driving for approx. 200 m.
      3. 3.2.3 Repeat entire procedure once.