Checking Vacuum Pump

Information 

This check mainly involves examining the secondary load connection due to problems. The main connection (brake booster) is not checked. If the main connection (brake booster) is faulty, pedal forces will increase during braking in the same way as if the brake booster was faulty.

1. Disconnect hose -1-  on the vacuum pump -2-  .

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Disconnecting hose on vacuum pump

2. Check the vacuum pump -2-  .
   1. 2.1 Connect vacuum tester >VAS 6213 - Hand vacuum pump  to the secondary load connection -3-. 
   2. 2.2 Move the lever on the vacuum tester to Open (vacuum).
   3. 2.3 Start engine and leave it running at idle speed with slightly changing revs.
   4. 2.4 Check a vacuum of at least 500 mbar or 0.5 bar.
   5. 2.5 If the vacuum is not maintained, i.e. the pointer moves towards 0 bar, the vacuum pump is faulty -2-  : Replace vacuum pump -2-  .

      > 477619 REMOVING AND INSTALLING VACUUM PUMP 

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.

      Checking vacuum pump

3. This defect can cause engine oil to get into the vacuum system:

   Visually check the lines and switching valves and replace them if necessary or clean them with solvent naphtha.

4. Remove vacuum tester and insert hose for secondary load connection into the vacuum pump.