Removing Valve-Stem Seals

Information 

When required, all valve-stem seals on both cylinder rows must be replaced.

Information 

• Before switching to another cylinder, the cylinder must be positioned at the bottom dead centre and supplied with compressed air (see above). 

Information 

• Position the pistons of the relevant cylinder at the bottom dead centre. 
• Each piston is pressed downwards as pressure builds up in the cylinder. 

1. Position the pistons of the relevant cylinder at the bottom dead centre. To do this, guide the timing chain carefully when turning the crankshaft.
2. Screw in compressed-air hose from the valve key assembly/disassembly tool for the Cayenne NR.54-1  tool set (or similar) in the relevant spark plug bore so that it is tightly sealed. Apply compressed air constantly to cylinder (at least 6 bar overpressure). This builds up pressure in the cylinder so that the valve does not fall into the cylinder while you are working.  Replace all four valve-stem seals for a cylinder and refit valve keys. Only then fit compressed-air hose on the next cylinder and apply compressed air constantly.
3. Fit and set the tool on the cylinder head
   1. 3.1. Screw -1-  a holder with the appropriate thread into its matching thread on the cylinder head. The hooking piece -2-  is pre-fitted in the holder.
      Fig 1: Fitting Hook On Cylinder Head

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   2. 3.2. Insert the appropriate plastic guide -1-  in place of the tappet.
      Fig 2: Inserting Plastic Guide

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   3. 3.3. Insert assembly cartridge -1-  for the valve keys into the plastic guide.
      Fig 3: Inserting Assembly Cartridge

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   4. 3.4. Hook the lever (assembly bar) -1-  into the hook and place correctly onto the assembly cartridge. Make sure that the tool and equipment can be effective directly.
      Fig 4: Fitting Assembly Bar Correctly Onto Assembly Cartridge

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.
4. Remove the valve keys
   1. 4.1. Press the assembly cartridge with the lever (assembly bar) against the force of the valve-spring and keep pressed. Press down the tool. The knurled screw of the assembly cartridge pushes forward -1-  .
      Fig 5: Pressing Assembly Cartridge And Lever

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.
      Fig 6: Pressing Down Lever And Knurled Screw

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.

      Information 

      The mechanic must practise for use of the assembly cartridge to be effective. Some repetitions must be made to ensure that the valve keys are correctly held in place.

   2. 4.2. Turn the knurled screw back and forth -1-  until the valve keys snap into place and are held there -2-  in the assembly cartridge. The knurled screw retracts.
      Fig 7: Turning Knurled Screw Back And Forth

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   3. 4.3. Remove the assembly cartridge and check correct position of both valve keys -1-  .
      Fig 8: Checking Position Of Valve Keys In Assembly Cartridge

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   4. 4.4. Pull out the knurled screw from the assembly cartridge -1-  and knock out the valve keys -2-  .
      Fig 9: Removing Valve Keys

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.
5. Remove valve springs, spring plate and valve keys from the cylinder head.
6. Withdraw sliding sleeve of puller 3364  . When positioning the puller 3364  on the fitted valve-stem seal, ensure that the metal edge of the valve-stem seal is positioned behind the corresponding metal edge of the puller. -1- 
   Fig 10: Identifying Valve-Stem Seal And Puller

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   Fig 11: Identifying Valve-Stem Seal In Puller

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
7. When engaging the puller 3364  , push sliding sleeve down and close tool. -arrow- 
   Fig 12: Pushing Sliding Sleeve

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
8. Remove valve-stem seal by activating the negative (slide) hammer. -arrow-  . Repeat procedure for valves on pressurised cylinder (reposition tool accordingly).
   Fig 13: Removing Valve-Stem Seal

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.