Adjusting And Calibrating Brake Shoes

Information 

• Only make adjustments at the two adjusting screws on the rear wheels  .
• Make sure that the lines for the electric parking brake (EPB) are routed and guided correctly  .

Information 

In the event of unfavorable tolerances, the brake pads may prevent the brake disc from turning freely. The brake pads may have to be carefully pressed back slightly and evenly.

1. Unscrew screw plug -2-  on the rear brake disc -1-  .

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Rear brake disc

   Information 

   The terms "Ignition on" and "Starting engine" are re-defined for fully electric vehicles (battery electric vehicles - BEV).

   Establishing operational readiness/Ignition on: 

   Prerequisites for establishing operational readiness: High-voltage battery is sufficiently charged, remove vehicle charging cable from the vehicle charge port, put driver's key in the emergency start tray.

   Establishing operational readiness automatically: Get into the vehicle and close the driver's door. The driver's key is recognized inside the vehicle. Operational readiness is established.

   Establishing operational readiness manually: Press Start/Stop switch. The driver's key is recognized inside the vehicle. Operational readiness is established.

   Establishing operational readiness/Starting engine: 

   Establish operational readiness and engage transmission range. The vehicle is now ready to drive and can be moved.

   Ending operational readiness/Switching off ignition 

   Ending operational readiness automatically: Get out of the vehicle with the driver's key and close the driver door. The driver's key is no longer detected outside the vehicle. Operational readiness ends.

   Ending operational readiness manually: Press Start/Stop switch until the instrument cluster is switched off.

   Ending driving readiness/Stopping engine 

   Vehicle is stationary: Press the P button on the instrument cluster. The vehicle is parked.

2. Release electric parking brake so that the brake discs can turn freely.
3. Adjust the brake shoes.
   1. 3.1  Connect the PIWIS Tester  to the vehicle and switch on the PIWIS Tester  .
   2. 3.2  Establish operational readiness/switch on ignition.
   3. 3.3  Start diagnostics.
   4. 3.4  Select "Brake electronics"  control unit.
   5. 3.5  Select the "Maintenance/repairs"  tab.
   6. 3.6  Select the "Commissioning"  menu item and press F12 to continue.
   7. 3.7  Select the "Set parking brake"  function and press F12 to continue.
   8. 3.8 Adjust the brake shoes  .
      1. 3.8.1  Turn the relevant brake disc with the opening to the adjusting screw position.

         Information 

         The subsequent torque of the rear wheel must be greater than 100 Nm (74 ftlb.).

      2. 3.8.2  Using a screwdriver, adjust the adjusting screw until the rear wheel can no longer be turned.

         Information 

         The rear brake discs must be able to turn freely.

      3. 3.8.3  Then, loosen by 14 (+/- 1) clicks of the adjusting screw.

         Information 

         A calculated value in the positive range means: Turn adjusting screw in direction A - loosen.

         A calculated value in the negative range means: Turn adjusting screw in direction B - tighten.

      4. 3.8.4  Re-adjust the adjusting screw in accordance with the instructions on the PIWIS Tester if necessary.

         > adjustment value 0.15 mm Corresponds to 1 click on the adjusting screw View of adjusting screw, left: 

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.

      Adjusting screw, left

      A	Direction of rotation A = loosen
      B	Direction of rotation B = tighten

      View of adjusting screw, right: 

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.

      Adjusting screw, right

      A	Direction of rotation A = loosen
      B	Direction of rotation B = tighten

      Information 

      • The "Grind down parking brake" function must be started for all brake variants (grey cast-iron/PSCB/PCCB), regardless of whether the brake is ground down  .
      • If the function is not started, the parking brake cannot then be calibrated  .
4. Grind down the parking brake.
   1. 4.1  Connect the PIWIS Tester  to the vehicle and switch on the PIWIS Tester  .
   2. 4.2  Establish operational readiness/switch on ignition.
   3. 4.3  Start diagnostics.
   4. 4.4  Select "Brake electronics"  control unit.
   5. 4.5  Select the "Maintenance/repairs"  tab.
   6. 4.6  Select the "Commissioning"  menu item and press F12 to continue.
   7. 4.7  Select the "Grind down parking brake"  function and press F12 to continue.
   8. 4.8  Follow the instructions on the Tester.
5. Calibrate brake shoes.
   1. 5.1  Connect the PIWIS Tester  to the vehicle and switch on the PIWIS Tester  .
   2. 5.2  Establish operational readiness/switch on ignition.
   3. 5.3  Start diagnostics.
   4. 5.4  Select "Brake electronics"  control unit.
   5. 5.5  Select the "Maintenance/repairs"  tab.
   6. 5.6  Select the "Commissioning"  menu item and press F12 to continue.
   7. 5.7  Select the "Calibrate parking brake"  function and press F12 to continue.
   8. 5.8  Follow the instructions on the Tester.
6. Actuate electric parking brake several times and check that the actuators open and close correctly on both sides.
7. Position brake pads by pressing the brake several times.
8. Fit and tighten screw plug -2-  on the rear brake disc -1-  .

   > Tightening torque 15 Nm (11 ftlb.) 

Courtesy of PORSCHE CARS NORTH AMERICA, INC.

Rear brake disc