GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 26999-10 Compression Gauge Adapter
    •  J 26999-30 Compression Gauge Adapter
    • J 38606 Valve Spring Compressor

Removal Procedure


    Object Number: 65002  Size: SH
  1. Remove the engine cover from the vehicle. Refer to Engine Cover Replacement in Interior Trim.
  2. Disconnect the battery negative cables from the batteries. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  3. Important: Mark the assemblies so these can be returned to the original locations.

  4. Remove the valve rocker arm, shaft, and the push rod from the cylinder being serviced. Refer to Valve Rocker Arm, Shaft, and Push Rod Replacement .
  5. Remove the glow plugs from the cylinder being serviced.
  6. Important: Rotate the cylinder to be service to the bottom of the stroke. This is to ensure that the engine does not rotate when the compressed air is applied to the cylinder being serviced.

  7. Install the J 26999-10 or the J 26999-30 into the glow plug hole.
  8. Apply compressed air to hold the valves in place. If the compressed air is released, the valves can drop into the cylinder.
  9. Use the J 38606 in order to compress the valve spring. If the spring will not compress, tap on the tool lightly with a mallet in order to loosen the cap or rotator from the valve keys.

  10. Object Number: 526635  Size: SH
  11. Remove the valve keys from the valve stem (exhaust valve shown).
  12. Carefully release the valve spring tension.
  13. Remove the cap or the rotator, the shield, and the valve spring with the damper (exhaust valve shown).
  14. Remove the valve stem oil seals.

Installation Procedure


    Object Number: 526635  Size: SH

    Notice: Air pressure should remain applied to the cylinder for installation.

  1. Apply a small amount of clean engine oil to the valve stem.
  2. Install the new valve stem oil seals.
  3. Install the valve spring with the damper, the shield, and the cap or the rotator (exhaust valve shown).
  4. Install the valve keys to the valve stem (exhaust valve shown).
  5. • Install the valve keys. Use grease in order to hold the valve keys in place.
    • Carefully release the valve spring pressure. Make sure the valve keys stay in place.
    • Remove the J 38606 or the J 26999-30 and the J 26999-10 .

    Object Number: 65002  Size: SH
  6. Install the glow plugs to the cylinder being serviced.
  7. • For the left cylinder head, refer to Glow Plug Replacement - Left Side in Engine Controls-6.5L.
    • For the right cylinder head, refer to Glow Plug Replacement - Right Side in Engine Controls-6.5L.
  8. Install the valve rocker arm, shafts, and the push rod to the cylinder being serviced. Refer to Valve Rocker Arm, Shaft, and Push Rod Replacement .
  9. Install the engine cover to the vehicle. Refer to Engine Cover Replacement in Interior Trim.
  10. Connect the battery negatives cables to the batteries. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.