34 10 014 Adjusting handbrake

Special tools required: 

• 32 1 030 

  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: carry out readjustment.

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

  The parking brake must be reset if the actuation stroke is greater than 10 teeth.

See STEERING AND WHEEL ALIGNMENT - SPECIAL TOOLS .

1. Setting instruction for brake shoes (basic setting) 

   Unclip gaiter  for parking brake lever.

   Lock adjuster unit (ASZE).

   Actuate parking brake lever. Screw in special tool 32 1 030  partially. Press stop (1) of adjusting spring back to such an extent that retaining hook (2) engages in stop (1).

   Fig 1: Identifying Special Tool (32 1 030)

   Courtesy of BMW OF NORTH AMERICA, INC.

   Completely unscrew one wheel stud on each rear wheel.

   Installation: 

   Tightening torque, see 36 10 WHEELS .

   Turn wheel until adjustment screw is visible in tapped hole.

   Fig 2: Locating Wheel Stud

   Courtesy of BMW OF NORTH AMERICA, INC.

   Turn adjusting screw with a screwdriver until wheel cannot be turned anymore by hand.

   Then at adjusting screw:

   • Release 185 dia. duo-servo brake 8 notches
   • Release 160 dia. duo-servo brake 9 notches
   IMPORTANT: Basic adjustment with fewer than 8 notches on the duoservo brake may lead to the brake shoes being damaged. Reducing the number of notches on the duo-servo brake to shorten lever travel is not permitted.
   Fig 3: Turning Adjusting Screw

   Courtesy of BMW OF NORTH AMERICA, INC.

   Unlock adjuster unit (ASZE).

   Lever out restraining hook (2) with a suitable screwdriver.

   Restraining hook (2) must detach from stop (1) of adjusting spring.

   Fig 4: Identifying Special Tool (32 1 030)

   Courtesy of BMW OF NORTH AMERICA, INC.
   IMPORTANT: Follow instructions for Brake testing  for test stand.
2. Setting instruction for parking brake Bowden cables 

   The parking brake lever must be applied 5 times with medium hand force.

   1. 2.1 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".

      • Without locking differential ≤150 N.
      • With locking differential ≥ 200 N (possibly odd display).

      1st tooth:  No increase in braking force with regard to 0th tooth. Indicator lamp can be lit.

      2nd tooth:  Indicator lamp must be lit.

      3rd tooth:  Increase in braking force.

      5th tooth:  The brake force display must have reached ≥ 400 N.

      Checking brake force differential at wheel: 

      Apply parking brake until a wheel circumferential force (brake force display) of min. 1000 N is reached.

      Max. permitted brake force differential right/left ≤35 % (referred to greater brake value).

3. Braking in the duo-servo parking brake 

   The following braking-in procedures are applicable in case of insufficient braking effect or after replacing brake discs and/or brake shoes.

   1. 3.1 On brake analyzer 

      Apply parking brake lever until wheel circumferential force at first wheel is 800 N.

      Lock parking brake lever in next lower tooth.

      Release parking brake lever after approx. 2 minutes.

   2. 3.2 When driving on road 

      (If possible inside the company grounds or on an unused road)

      When driving at low speed (max. 40 km/h) apply parking brake lever until a braking effect can be felt.

      Pull parking brake lever into the next notch and continue driving for approx. 400 metres (max. 40 km/h).

      A basic requirement is that parking brake is adjusted uniformly.

      NOTE: If necessary, repeat braking-in procedure.
      Allow brake to cool down sufficiently.