Brakes and Traction Control: Adjustments
WM 468315 Adjusting and calibrating brake
Technical values
Adjusting
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 Reworking parking-brake shoes Procedures
- Adjustments must only be carried out at the two rear wheel adjustment devices.
- Make sure that the EPB cables are routed and guided correctly.
The rear wheels must be removed in order to access the adjustment device. -> 440519 Removing and installing wheel Removal and Replacement
In the event of unfavourable 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.
1. Raise the vehicle. -> 4X00IN Lifting the vehicle Service and Repair
2. Release the EPB so that the wheels and brake discs can turn freely.
3. Move the brake shoes into installation position using the Porsche System Tester. Select ]]Parking brake[[ in the control unit overview. Select >>Drive links/Tests]]All[[>>Move to installation position>>.
4. 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 > 100 Nm (74 ftlb.). Then loosen 17 (+/- 1) clicks of the adjustment device (wheels must be able to turn freely).
5. 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[[.
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
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: 2.6 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.
6. Grind parking-brake shoes (not PCCB!) -> 468350 Reworking (grinding) parking-brake shoes Procedures.
7. Calibrate the EPB using the Porsche System Tester. To do this, select ]]Parking brake[[ in the control unit overview. Select ]]Maintenance/Repairs[[ ]]Calibration[[.
8. 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.
9. Fit wheels -> 440519 Removing and installing wheel - section on "Installing" Removal and Replacement.