Cylinder Head Replacement

Tools Required
• J 36660-A Torque Angle Meter
• J 42385-200 Thread Repair Kit

Removal Procedure

1. Remove the generator bracket. Refer to Generator Replacement in Engine Electrical.
2. Remove the coolant air bleed pipe. Refer to Coolant Air Bleed Pipe Assembly Replacement in Engine Cooling.
3. Remove the exhaust manifold. Refer to Exhaust Manifold Replacement -
4. Remove the pushrods. Refer to Valve Rocker Arm and Push Rod Replacement .
   
   

   Important

   The cylinder head bolts are NOT reusable.

5. Remove the cylinder head bolts.

   Notice

   After removal, place the cylinder head on two wood blocks to prevent damage to the sealing surfaces.

6. Remove the cylinder head.
   
   
7. Remove the cylinder head gasket.
8. Discard the gasket.
9. Discard the cylinder head bolts.
10. Clean and inspect the cylinder head. Refer to Cylinder Head Cleaning and Inspection in Engine Mechanical - 4.8L, 5.3L, and 6.0L Unit Repair.

Installation Procedure

Caution

Wear safety glasses in order to avoid eye damage.

Notice

Clean all dirt, debris, and coolant from the engine block cylinder head bolt holes. Failure to remove all foreign material may result in damaged threads, improperly tightened fasteners or damage to components.

Important

• Do not reuse the cylinder head bolts. Install NEW cylinder head bolts during assembly.
• Do not use any type of sealant on the cylinder head gasket (unless specified).
• The cylinder head gaskets must be installed in the proper direction and position.

1. Clean the engine block cylinder head bolt holes (if required). Thread repair tool J 42385-107, found in J 42385-200 may be used to clean the threads of old threadlocking material.
2. Use spray cleaner GM U.S. P/N 12346139, P/N 12377981, Canada P/N 10953463, or equivalent into the hole.
3. Clean the cylinder head bolt holes with compressed air.
4. Check the cylinder head locating pins for proper installation.

   Important

   When properly installed, the tab on the cylinder head gasket will be located of center or closer to the front of the engine.

   
   
   
5. Install the NEW cylinder head gasket onto the locating pins.
   
   
6. Install the cylinder head onto the locating pins and gasket.
7. Install the NEW cylinder head bolts.
   
   

   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.

8. Tighten the cylinder head bolts. Tighten
   1. Tighten the M11 cylinder head bolts a first pass in sequence to 30 N·m (22 lb ft).
   2. Tighten the M11 cylinder head bolts a second pass in sequence to 90 degrees using J 36660-A .
   3. Tighten the M11 cylinder head bolts (1,2,3,4,5,6,7,8) to 90 degrees and the M11 cylinder head bolts (9 and 10) to 50 degrees a final pass in sequence using J 36660-A .
   4. Tighten the M8 cylinder head bolts (11,12,13,14,15) to 30 N·m (22 lb ft). Begin with the center bolt (11) and alternating side-to-side, work outward tightening all of the bolts.
   
   
   
9. The cylinder head gasket displacement can be verified by markings visible on the top side of the gasket locating tab.
   • Some 4.8/5.3 L head gaskets may have 53 stamped onto the locating tab.
   • Some 6.0 L head gaskets may have 60 stamped onto the locating tab.
10. Install the pushrods. Refer to Valve Rocker Arm and Push Rod Replacement .
11. Install the exhaust manifold. Refer to Exhaust Manifold Replacement
12. Install the coolant air bleed pipe. Refer to Coolant Air Bleed Pipe Assembly Replacement in Engine Cooling.
13. Install the generator bracket. Refer to Generator Replacement in Engine Electrical.