Adjusting And Calibrating Parking-Brake Shoes
Information
- The electric parking brake with asbestos-free brake pads must never be adjusted in such a way that the pad has to grind free during operation.
- Adjustments must only be carried out at the two rear wheel adjustment devices.
- Make sure that the EPB cables are routed and guided correctly.
In the event of unfavorable tolerances, the brake pads may prevent the brake disc from turning freely. If this happens, the brake pads must be pressed back slightly and uniformly using a water pump pliers.
- Raise the vehicle.
- Remove rear wheels.
- Release the EPB so that the brake discs can turn freely.
- Move the brake shoes into assembly position using the Porsche System Tester. Select >>Parking brake<< in the control unit overview. Select >>Drive links/checks>>All<<>>Move to assembly position<<.
- Adjust brake shoes on both sides. To do this, turn the relevant brake disc with the opening to the adjustment device position. Using a screwdriver, adjust the adjustment device until the brake disc can no longer be turned. The subsequent torque of the brake disc must be greater than 100 Nm (74 ftlb.). Then loosen 17 (+/- 1) clicks of the adjustment device (brake discs must be able to turn freely).
- Using the Porsche System Tester, select >>Parking brake<< in the control unit overview. Select >>Maintenance/repairs<<>>Check parking brake basic setting<<.
It may be necessary to fine-tune the adjustment device after selecting >>Check parking brake basic setting<<.
| Location | Description | Type | Basic value | Tolerance |
|---|---|---|---|---|
| Actual dimension | Displayed on the Tester! Actual gap dimension at left and right measured between the shoe and drum in millimeters. | Control value | 000 mm | |
| Required dimension | Displayed on the Tester! Required dimension between the shoe and drum in millimeters. | Control value | + 2, 2 mm | +/- 0.3 mm |
| Adjustment dimension | Must be calculated! Value (in millimeters) by which the adjustment device must be turned. | Control value | 000 mm |
Adjustment dimension = required dimension - actual dimension (required dimension minus actual dimension)
Left adjustment device, A - tighten, B - loosen
Left adjustment device, A - tighten, B - loosen
> Control value 0.15 mm
Corresponds to 1 click on the adjustment device
Adjustment dimension = required dimension - actual dimension (required dimension minus actual dimension)
Information
A calculated value in the positive range means: Turn adjustment device towards A - loosen.
A calculated value in the negative range means: Turn adjustment device towards B - tighten.
Example:
Actual dimension: 2.6 mm
Required dimension: 2.0 mm (+/- 0.3 mm)
Adjustment dimension = required dimension - actual dimension
Adjustment dimension = 2.0 mm - 2.6 mm
Adjustment dimension = -0.6 mm
-0.6 mm: 0.15 mm = - 4 clicks (0.15 mm corresponds to one click!)
Adjustment dimension = -0.6 mm: This means that the gap dimension is too big and the adjustment device must be adjusted towards B - tighten.