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Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 994 (Engine Mechanical - 6.6L (LLY)) >> Repair Instructions >> On-Vehicle Repair Instructions >> Valve Stem Oil Seal and Valve Spring Replacement >> Removal Procedure

Removal Procedure

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Remove the upper and lower fan shroud. Refer to Fan Shroud Replacement - Lower and Fan Shroud Replacement - Upper (W/O M74) or Fan Shroud Replacement - Upper (W/M74) in Engine Cooling.
  2. Remove the valve rocker arm shaft, valve bridges, and pushrods for the cylinder head being serviced. Refer to Valve Rocker Arm, Shaft, and Push Rod Replacement .
  3. Remove the glow plug for the cylinder requiring service. Refer to Glow Plug Replacement - Bank 1 or Glow Plug Replacement - Bank 2 .
  4. In order to apply shop air to the cylinders use the following procedures to modify J 26999-20  (1) and J 26999  (2):
    1. Remove the valve core from J 26999-20  to allow air to flow.
    2. Remove the quick connect fitting from J 26999  .
    3. Adapt the quick connect fitting in order to use for shop air.
    4. Connect the quick connect fitting to J 26999-20  .
    5. Fig 1: View Of J 26999-20 & J 26999
    GM702726Courtesy of GENERAL MOTORS CORP.
    IMPORTANT: Rotate the cylinder to be serviced 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.
  5. Install J 26999-20  into the glow plug hole for the cylinder being serviced.
  6. Apply compressed air to hold the valves in place. If the compressed air is released, the valves can drop into the cylinder.
    7. 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. Install J 44646  to the rocker arm bosses on the cylinder head.

    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.

  8. Using J 44646  compress the valve spring.
    9. Fig 2: Compressing Valve Spring Using J 44646
    GM702702Courtesy of GENERAL MOTORS CORP.
  9. Remove the valve keys (1) from the valve stem.
  10. Carefully release the valve spring tension.
  11. Remove the valve spring upper seat (2) and the valve spring (3).
  12. Remove the valve stem oil seal (4).
  13. Remove the valve spring lower seat (5).
  14. Continue removing the remaining valve stem seals for the cylinder using the above procedure.
    15. Fig 3: View Of Valve Stem & Spring Components
    GM663504Courtesy of GENERAL MOTORS CORP.
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