GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 Chevy P12 Chassis 🢒 Engine 🢒 Engine Mechanical - 7.4L 🢒 Cylinder Head Replacement

Removal Procedure

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  1. Disconnect the battery negative cable from the battery.
  2. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  3. Remove the engine electrical wiring harness and lay to the side.
  4. Disconnect the engine ground strap. Refer to Engine Ground Strap Replacement in Engine Electrical.
  5. Remove the fan shroud from the radiator. Refer to Fan Shroud Replacement in Engine Cooling.
  6. Remove the fan clutch assembly. Refer Fan Clutch Replacement in Engine Cooling.
  7. Remove the air conditioning compressor from the mounting bracket. Refer to Air Conditioning Compressor Replacement in HVAC Systems with A/C-Manual.
  8. Remove the air conditioning mounting bracket from the engine block.
  9. Remove the generator from the mounting bracket. Refer to Generator Replacement in Engine Electrical.
  10. Remove the generator mounting bracket from the engine block. Refer to Generator Bracket Replacement in Engine Electrical.
  11. Remove the upper intake manifold from the lower intake manifold. Refer to Intake Manifold Replacement .
  12. Remove the lower intake manifold from the engine block. Refer to Intake Manifold Replacement .
  13. Remove the valve rocker arm cover from the cylinder head. Refer to Valve Rocker Arm Cover Replacement .
  14. Remove the valve rocker arms and pushrods from the cylinder head. Refer to Valve Rocker Arm and Push Rod Replacement .
  15. Remove the spark plugs from the cylinder head. Refer to Spark Plug Replacement in Engine Electrical.
  16. Remove the exhaust manifold from the cylinder head. Refer to Exhaust Manifold Replacement .

    17. Object Number: 64909 Size: SH
  17. Remove cylinder head bolts from the engine block.
  18. Remove the cylinder head and gasket from the engine block.
  19. Clean and inspect the sealing surfaces on the engine block. Refer to Cylinder Head Cleaning and Inspection .
  20. Disassemble the cylinder head. Refer to Cylinder Head Disassemble .

Installation Procedure

    Important: Do not use sealer on the composition gaskets, and make sure that the punch code (7.4L) on the cylinder head gasket is facing up.

  1. Assemble the cylinder head. Refer to Cylinder Head Assemble .

    2. Object Number: 64909 Size: SH
  2. Install the cylinder head gasket to the engine block.

    3. Important: Make sure that the threads on the cylinder head bolts are clean as well as the threaded holes in the engine block.

  3. Install the cylinder head to the engine block.
  4. Coat at least the first 8 threads of the cylinder head bolts with GM sealing compound P/N 12346004.

    5. Object Number: 64549 Size: SH

    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.

  5. Install the cylinder head bolts to the cylinder head and tighten finger tight.

    6. Tighten

        • Tighten the first sequence to 50 N·m (37 lb ft).
        • Tighten the second sequence 60 degrees.
        • Tighten the final sequence for bolts 1, 2, 3, 6, 7, 8, 9, 12, 13, 14, 15 and 16, to 90 degrees, and bolts 4, 5, 10, and 11 to 30 degrees.
  6. Install the valve rocker arms and pushrods to the cylinder head. Refer to Valve Rocker Arm and Push Rod Replacement .
  7. Install the valve rocker arm cover to the cylinder head. Refer to Valve Rocker Arm Cover Replacement .
  8. Install the exhaust manifold to the cylinder head. Refer to Exhaust Manifold Replacement .
  9. Install the spark plugs to the cylinder head. Refer to Spark Plug Replacement in Engine Electrical.
  10. Install the lower intake manifold to the cylinder heads. Refer to Intake Manifold Replacement .
  11. Install the upper intake manifold to the lower intake manifold. Refer to Intake Manifold Replacement .
  12. Install the engine ground strap to the engine block. Refer to Engine Ground Strap Replacement in Engine Electrical.
  13. Install the generator mounting bracket to the engine block. Refer to Generator Bracket Replacement in Engine Electrical.
  14. Install the generator to the mounting bracket. Refer to Generator Replacement in Engine Electrical.
  15. Install the air conditioning mounting bracket to the engine head.
  16. Install the air conditioning compressor to the mounting bracket. Refer to Air Conditioning Compressor Replacement in HVAC Systems with A/C-Manual.
  17. Install the fan clutch assembly. Refer Fan Clutch Replacement in Engine Cooling.
  18. Install the fan shroud to the radiator. Refer to Fan Shroud Replacement in Engine Cooling.
  19. Install the engine electrical wiring harness.
  20. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.

    21. Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  21. Connect the battery negative cable.