GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 26999 Compression Gauge
    • J 26999-20 Compression Gauge Adapter
    • J 44646 Valve Spring Compressor
    • J 44640 Valve Stem Seal Installer

Removal Procedure


    Object Number: 401885  Size: SH
  1. Disconnect the battery negative cables from the batteries. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  2. Remove the wheelhouse inner fender panels (1) for both sides or for the side requiring service.
  3. Remove the valve rocker arm shaft assembly, valve bridges, and pushrods for the cylinder head being service. Refer to Valve Rocker Arm, Shaft, and Push Rod Replacement .
  4. Remove the upper and lower fan shroud in order to access the crankshaft balancer bolt. Refer to Engine Coolant Fan Lower Shroud Replacement and Engine Coolant Fan Upper Shroud Replacement in Engine Cooling.
  5. The engine will be rotated during the procedure using the crankshaft balancer bolt.


    Object Number: 660512  Size: SH
  6. Working through the wheel house opening remove the wire strap connector, Federal (2), California (1), for the glow plugs.
  7. Remove the glow plug for the cylinder requiring service.

  8. Object Number: 660477  Size: SH
  9. Remove the fuel injector return pipe eye bolts and washers.
  10. Remove the fuel injector return pipe assembly.

  11. Object Number: 702726  Size: SH
  12. In order to apply shop air to the engine cylinders use the following procedures to modify the J 26999-20  (1) and the J 26999  (2):
  13. 9.1. Remove the valve core from the J 26999-20 to allow air to flow.
    9.2. Remove the quick connect fitting from the J 26999 .
    9.3. Adapt the quick connect fitting in order to use for shop air.
    9.4. Connect the quick connect fitting to the J 26999-20 .

    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.

  14. Install the J 26999-20 into the glow plug hole for the cylinder being serviced.
  15. Apply compressed air to hold the valves in place. If the compressed air is released, the valves can drop into the cylinder.

  16. Object Number: 702702  Size: SH

    Caution: Compressed valve springs have high tension against the valve spring compressor. Valve springs that are not properly compressed by or released from the valve spring compressor can be ejected from the valve spring compressor with intense force. Use care when compressing or releasing the valve spring with the valve spring compressor and when removing or installing the valve stem keys. Failing to use care may cause personal injury.

  17. Install the J 44646 to the rocker arm bosses on the cylinder head.
  18. The J 44646 should be installed in the rocker arm boss next to the cylinder being serviced. The pivot pin can be removed from the stand to allow the stand to be installed. The lever has different locating holes for the pivot pin depending on available clearance. The lever is also notched for different locations of the compressor.

  19. Using the J 44646 compress the valve spring.
  20. Remove the valve keys from the valve stem.
  21. Carefully release the valve spring tension.

  22. Object Number: 663504  Size: SH
  23. Remove the upper valve spring seat (2) and the valve spring (3).
  24. Remove the valve stem oil seal (4).
  25. Remove the valve spring lower seat (5).
  26. Continue removing the remaining valve stem seals for that cylinder using the above procedure.

Installation Procedure


    Object Number: 663571  Size: SH

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

  1. Install the valve spring lower seat.
  2. Install the valve stem seal using the J 44640 .

  3. Object Number: 663504  Size: SH
  4. Install the valve spring (3), the painted end of the valve spring goes toward the cylinder head.
  5. Install the valve spring upper seat (2).

  6. Object Number: 702702  Size: SH

    Caution: Compressed valve springs have high tension against the valve spring compressor. Valve springs that are not properly compressed by or released from the valve spring compressor can be ejected from the valve spring compressor with intense force. Use care when compressing or releasing the valve spring with the valve spring compressor and when removing or installing the valve stem keys. Failing to use care may cause personal injury.

  7. Using the J 44646 compress the valve spring.
  8. Install the valve keys to the valve stem.
  9. Notice: The valve stem keys must correctly seat in the valve spring cap. Engine damage may occur by not installing properly.

  10. Carefully release the valve spring pressure. Make sure the valve keys stay in place.
  11. Continue to install the three remaining valve stem seals for that cylinder.

  12. Object Number: 702726  Size: SH
  13. Release the compressed air holding the valves in place.
  14. Remove the J 26999-20  (1) from the glow plug hole.
  15. Continue to replace the valve stem seals on the remaining cylinders using the above procedures.

  16. Object Number: 660477  Size: SH
  17. Install the fuel injector return pipe assembly.
  18. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  19. Install the fuel injector return pipe to injector eye bolts and washers.
  20. Tighten
    Tighten the fuel injector return pipe to injector eye bolts to 15 N·m (133 lb in).

  21. Install the fuel injector return pipe to cylinder head eye bolts and washers.
  22. Tighten
    Tighten the fuel injector return pipe to cylinder head eye bolts to 15 N·m (133 lb in).


    Object Number: 660512  Size: SH
  23. Install the glow plug to the cylinder being serviced.
  24. Tighten
    Tighten the glow plugs to 18 N·m (13 lb ft).

  25. Install the glow plug connector, Federal (2), California (1).
  26. Tighten
    Tighten the glow plug connector nuts to 2 N·m (18 lb in).

  27. Install the valve rocker arm shaft assembly, the valve bridges, and the push rods Refer to Valve Rocker Arm, Shaft, and Push Rod Replacement .

  28. Object Number: 401885  Size: SH
  29. Install the wheelhouse inner fender panel(s) (1).
  30. Install the upper and lower fan shroud. Refer to Engine Coolant Fan Lower Shroud Replacement and Engine Coolant Fan Upper Shroud Replacement in Engine Cooling.
  31. Connect the battery negative cables to the batteries. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.