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.

It must be possible to brake with locked wheels with the handbrake.

The handbrake must be readjusted whenever the actuation stroke is greater than 10 teeth.

Basic handbrake adjustment is necessary:

• When replacing parking brake shoes.
• When replacing brake disks.
• In event of excessive actuation stroke (10 teeth).
• When replacing parking brake Bowden cables

1. Setting instruction for brake shoes (basic setting) 

   Lock adjuster unit (ASZE).

   Using special tool 32 1 030, press stop (1) of adjusting spring back to such an extent that retaining hook (2) engages in stop (1).

   Fig 1: Adjusting Spring Back With Special Tool 32 1 030

   Courtesy of BMW OF NORTH AMERICA, INC.

   Completely unscrew one wheel stud on each rear wheel.

   Installation: 

   Tighten to specified torque. 130-110 Nm.

   Turn wheel until adjustment screw is visible in tapped hole.

   Fig 2: Locating Rear Wheel

   Courtesy of BMW OF NORTH AMERICA, INC.

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

   Then unfasten the adjusting screw 8 notches.

   Fig 3: Turning Adjusting Screw With Screwdriver

   Courtesy of BMW OF NORTH AMERICA, INC.

   Unlock adjuster unit (ASZE).

   Lever restraint hook (2) outwards with a suitable screwdriver (1).

   Restraint hook (2) must disengage from stop of adjusting spring.

   Fig 4: Identifying Restraint Hook And Screwdriver

   Courtesy of BMW OF NORTH AMERICA, INC.
2. Setting instruction for parking brake Bowden cables

   The handbrake lever must be applied 5 times to approx. 400N actuating force.

   1. 2.1 On brake analyzer

      0th tooth (handbrake released): 

      Vehicles with manual transmission: Shift lever in neutral position

      Vehicles with automatic transmission: Selector lever in N position.

      • 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 ≥ tooth: 400 N.

      Checking brake force differential at wheel: 

      Apply handbrake 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. Breaking in the duo-servo parking brake 

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

   1. On brake analyzer 

      Apply handbrake lever until wheel circumferential force on first wheel is 800 N.

      Lock lever in next lower tooth.

      Release handbrake lever after approx. 2 minutes.

   2. When driving on road 

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

      At approx. 40 km/h, apply handbrake lever until braking action can be felt.

      Pull up handbrake lever into next notch and drive on for approx. 400 m.

      A basic requirement is that handbrake is adjusted uniformly.