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Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 271 (Engine Mechanical - 4.8L, 5.3L, 6.0L Or 6.2L (4 Of 5)) >> Off-Vehicle Repair Instructions (2 Of 3) >> Cylinder Head Disassemble >> Procedure

Cylinder Head Disassemble: Procedure

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    Fig 1: Compressing Valve Spring
    GM260151Courtesy of GENERAL MOTORS CORP.
    IMPORTANT:
    • With the components at room temperature, remove the spark plugs from the cylinder head.
    • Mark, organize, or sort the cylinder head components for assembly. Return the components to their original location during assembly.
  1. Remove the spark plugs from the cylinder heads.
  2. Use the J 8062  in order to compress the valve spring. See Special Tools .
    3. Fig 2: Valve Stem Keys, Valve Spring Cap & Valve Spring
    GM1559870Courtesy of GENERAL MOTORS CORP.
  3. Remove the valve stem keys (225).
  4. Remove the valve spring cap (224).
  5. Remove the valve spring (223).
  6. Remove the valves (228).
  7. Remove the valve stem oil seal (222). Refer to Separating Parts .
    8. Fig 3: Locating Cylinder Head Core Hole Plug
    GM1559873Courtesy of GENERAL MOTORS CORP.
  8. Remove the cylinder head core hole plugs (216), as required.
    9. Fig 4: Locating Coolant Temperature Sensor
    GM1559875Courtesy of GENERAL MOTORS CORP.
  9. Remove the coolant temperature sensor (725) from the left cylinder head.
    10. Fig 5: Locating Coolant Plug
    GM1559878Courtesy of GENERAL MOTORS CORP.
  10. Remove the cylinder head plug (229) from the right cylinder head.
    11. Fig 6: Rivet-Type Plug
    GM2046466Courtesy of GENERAL MOTORS CORP.
  11. Inspect for a leaking plug (1). Second design applications use a rivet-type plug at the top rear coolant passage of each cylinder head. If service of a leaking plug is required, it is necessary to remove the cylinder head from the engine to properly remove the plug.
    12. Fig 7: View Of Plug Assembly
    GM2060115Courtesy of GENERAL MOTORS CORP.
  12. Using a 6.43 mm (0.25 in) or smaller punch, remove the plug assembly (1) from the cylinder head.
    13. Fig 8: Engine Coolant Air Bleed Cover, Bolts & Seals
    GM1408862Courtesy of GENERAL MOTORS CORP.
  13. If plug removal is required, install a first design coolant air bleed cover (313), seal (308), and bolt (312) to complete the repair.
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