Bleeding The Brake System - Porsche Stability Management (Psm) Bleeding Routine

Information 

• Check brake fluid quality. Use only new Hydraulan 404 brake fluid. 
• Use a transparent hose and collecting bottle and make sure the brake fluid is clean and free of air bubbles during bleeding. 
• The help of another person is required. 
• Make sure there is sufficient brake fluid left during bleeding. The reservoir must not run dry. 
• The brake fluid level in the reservoir must be between the MIN and MAX markings after bleeding the brake system. 

  Information 

• If the pedal travel is too long or the pedal feels too soft, the following procedure must be carried out. 

1. Open and remove cap on brake fluid reservoir.
2. > VAS 6860 - Connect brake filling and bleeding equipment  to reservoir and switch on.
3. Set the bleeding pressure to 2.0 bar.

   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.

4. Bleed the brake system using the PIWIS Tester.
   1. 4.1  Connect the PIWIS Tester  to the vehicle and switch it on.
   2. 4.2 Establish operational readiness/ignition on. 
   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 "Service bleeding"  function and press F12 to continue.
   7. 4.7  Follow the instructions on the Tester.
5. Close and tighten bleeder valves.

   Front bleeder valves (grey cast iron): 

   > Tightening torque 14 Nm (10.5 ftlb.) 

   Front bleeder valves (PCCB): 

   > Tightening torque 20 Nm (15 ftlb.) 

   Rear bleeder valves (grey cast iron): 

   > Tightening torque 14 Nm (10.5 ftlb.) 

   Rear bleeder valves (PCCB): 

   > Tightening torque 20 Nm (15 ftlb.) 

6. Remove and empty collecting bottle, then carefully remove brake fluid residues from components, if necessary.
7. > VAS 6860 - Switch off brake filling and bleeding equipment  and detach connecting line from adapter.
8. Unscrew adapter on the reservoir.
9. Visually check the brake fluid level and correct, if necessary. The brake fluid level must be between the MIN and MAX markings -1-  .

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Min/Max markings for brake fluid

10. Screw on reservoir cap -1-  and tighten by hand.

    Courtesy of PORSCHE CARS NORTH AMERICA, INC.

    Cap on brake fluid reservoir

11. Establish operational readiness/switch on ignition, check brake pedal travel and pedal feel.
    1. 11.1  If the pedal travel or pressure point is not OK, repeat the bleeding routine.