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 . → 468350 GRINDING DOWN PARKING-BRAKE SHOES
- Adjustments must only be carried out at the two rear wheel adjustment devices.
- Make sure that the EPB cables are routed and guided correctly.
To access the adjustment device, the rear wheels must be removed.
→ 440519 REMOVING AND INSTALLING WHEEL .
→ 440519 REMOVING AND INSTALLING WHEEL WITH CENTRAL BOLT .
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 water pump pliers.
- Raise the vehicle. → 4X00IN LIFTING THE VEHICLE
- Release electric parking brake (EPB) so that the wheels and brake discs can turn freely.
- Move the brake shoes into installation position using PIWIS Tester II 9818 . Select >>Parking brake<< in the control unit overview. Select >>Drive links/checks<< >>All<< >>Move to installation position<<.
- Adjust brake shoes (on both wheels). To do this, turn the relevant rear wheel with the opening to the adjustment device position. Using a screwdriver, adjust the adjustment device until the wheel can no longer be turned. The subsequent torque of the wheel must be greater than 100 Nm (74 ftlb.). Then loosen the adjustment device by 12 clicks (wheels must be able to turn freely).
- Using PIWIS Tester II, 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 1 Tolerance 2 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 +1.8 mm +0.3 mm -0.2 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)
Courtesy of PORSCHE CARS NORTH AMERICA, INC.
Courtesy of PORSCHE CARS NORTH AMERICA, INC.
→ Control value: 0.15 mm
Corresponds to 1 click on the adjustment device
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.
Adjustment dimension = required dimension - actual dimension (required dimension minus actual dimension)
Example:
Actual dimension: 2.4 mm
Required dimension: 1.8 mm (+ 0.3 mm/- 0.2 mm)
Adjustment dimension = required dimension - actual dimension
Adjustment dimension = 1.8 mm - 2.4 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.
- Grind down parking-brake shoes (not for PCCB or compound brake discs with aluminum brake disc hubs!) → 468350 REWORKING (GRINDING) PARKING-BRAKE SHOES .
- Use PIWIS Tester II to calibrate the EPB. To do this, select >>Parking brake<< in the control unit overview. Select >>Maintenance/repairs<< >>Calibration<<.
- To check the function of the EPB, actuate the EPB button several times (press 2-3 times) and make sure that the actuators open and close on both sides.
Position disc brake pads by operating the brake several times.
- Fit wheels.
→ Installing Wheel .