GM Service Manual Online
For 1990-2009 cars only

Cylinder Head Disassemble F Car

Tools Required

J 8062 Valve Spring Compressor


    Object Number: 721939  Size: MH

    Important: Remove the spark plugs from the cylinder head with the components at room temperature.

    Mark, organize, or sort the cylinder head components for assembly. Return the components to their original location during assembly.

    Do not remove the cylinder head expansion plugs (9) or valve seats (10 and 12) unless service is required.

    A second design valve stem oil seal and shim assembly may be used on later engines.

    A separate spring shim is not required with the second design seal and shim assembly.

  1. Remove the spark plugs from the cylinder heads.

  2. Object Number: 260151  Size: SH
  3. Use the J 8062 in order to compress the valve spring.

  4. Object Number: 721939  Size: MH
  5. Remove the valve stem keys (3).
  6. Remove the valve spring cap (4).
  7. Remove the valve spring (5).
  8. Remove the valves (11 and 13).
  9. Remove the first design valve stem oil seal (6).
  10. Remove the first design valve spring shim (7).
  11. Remove the second design valve stem oil seal and shim assembly (2). Refer to Separating Parts .

  12. Object Number: 490662  Size: SH
  13. Remove the cylinder head expansion plugs (1), if required.

  14. Object Number: 260086  Size: SH
  15. Remove the coolant sensor from the left cylinder head.

  16. Object Number: 260157  Size: SH
  17. Remove the coolant plug from the right cylinder head.

Cylinder Head Disassemble Y Car

Tools Required

J 8062 Valve Spring Compressor


    Object Number: 721939  Size: MH

    Important: Remove the spark plugs from the cylinder head with the components at room temperature.

    Mark, organize, or sort the cylinder head components for assembly. Return the components to their original location during assembly.

    Do not remove the cylinder head expansion plugs (9) or valve seats (10 and 12) unless service is required.

    A second design valve stem oil seal and shim assembly may be used on later engines.

    A separate spring shim is not required with the second design seal and shim assembly.

  1. Remove the spark plugs from the cylinder heads.

  2. Object Number: 260151  Size: SH
  3. Use the J 8062 in order to compress the valve spring.

  4. Object Number: 721939  Size: MH

    Important: Early design LS6 applications use a copper plated spring shim. A shim of the same design must be installed during assembly.

  5. Remove the valve stem keys (3).
  6. Remove the valve spring cap (4).
  7. Remove the valve spring (5).
  8. Remove the valves (11 and 13).
  9. Remove the first design valve stem oil seal (6).
  10. Remove the first design valve spring shim (7).
  11. Remove the second design valve stem oil seal and shim assembly (2). Refer to Separating Parts .

  12. Object Number: 490662  Size: SH
  13. Remove the cylinder head expansion plugs (1), if required.

  14. Object Number: 260086  Size: SH
  15. Remove the coolant sensor from the left cylinder head.

  16. Object Number: 260157  Size: SH
  17. Remove the coolant plug from the right cylinder head.