Cylinder Head Assembly: Service and Repair
This article has been updated with bulletin No.: 77-61-14Cylinder Head Removal and Installation Procedure
Installing brass plug into cylinder head:
Cylinder head bolt tightening sequence:
External coolant loss from the rear lower corner of the left cylinder head and front lower corner of the right cylinder head is the result of a sealing condition around the core clean-out hole in the cylinder head. This condition can be corrected by installing a brass plug kit (part No. 14077197), consisting of two brass plugs and one driver. To install plugs, remove cylinder head as outlined below, then proceed as follows:
1. Clean inside edge of plug hole, Fig. 8 , with a wire brush and suitable solvent.
2. Apply suitable sealant to sides of brass plug and hole.
3. Install plug slowly and squarely using an arbor press and plug driver, until plug is flush with head surface. If the plug deforms or pulls away from side of hole, lightly tap sides of plug to move back into contact with side of hole while sealant is still wet.
4. Remove all old sealant from cylinder head bolt holes in block using an M12 X 1.75 tap.
5. Clean block mating surfaces and remove any sheared brass or excessive sealant from cylinder head.
RIGHT SIDE
1. Remove intake manifold. Refer to, Intake Manifold/Service and Repair. Service and Repair
2. Remove injection lines.
3. If equipped with cruise control, remove cruise control transducer.
4. If equipped with A/C, remove upper fan shroud and A/C compressor belt.
5. Raise vehicle, then disconnect exhaust pipe at manifold flange.
6. If equipped with A/C, remove A/C compressor brace from exhaust manifold.
7. Disconnect glow plug wires and lower vehicle.
8. If equipped with A/C, discharge system, disconnect A/C compressor suction and discharge lines, then remove A/C compressor from brackets and remove.
9. Loosen dipstick tube front bracket and remove from stud.
10. Remove upper bracket from oil fill tube.
11. Remove wire loom bracket, rocker cover bolts and rocker cover.
12. Remove rocker arm assemblies, then remove pushrods. Prior to removing pushrods, mark upper end as an aid during reassembly. Failure to identify pushrods could result in incorrect installation, leading to premature wear or damage.
13. Drain cooling system, then remove air cleaner resonator and bracket.
14. Remove transmission fill tube bracket nut and position tube aside.
15. Disconnect heater, radiator and bypass hoses at coolant crossover, then remove crossover.
16. Remove generator upper bracket.
17. Remove cylinder head bolts.
18. Remove transmission dipstick at rear of head and remove tube.
19. Remove cylinder head.
20. Reverse procedure to install, noting the following:
IMPORTANT:
- The cylinder head torquing sequence has been revised. The new procedure incorporates torque angle in the final tightening sequence, similar to the current crankshaft and bearings installation procedure. For all model years of the 6.5L engine, use the information provided in this bulletin.
- Make sure that the block gasket surfaces are clean.
- The head gasket material is soft. Handle the gasket with care. Make sure the gasket surface is not creased or dented.
- Do not use a sealer on the Head Gasket. The head gasket is made with sealant on the gasket surface. Additional sealer may cause leakage or malfunction. In addition, some sealers may attack the initial sealant on the gasket.
1. Install the cylinder head gaskets to the block, over the cylinder head dowel pins.
Cylinder Head Bolt Tightening Sequence:
2. Install the cylinder heads to the block, over the cylinder head gaskets and the cylinder head dowel pins.
3. Apply thread sealant GM P/N 12345382 or equivalent, to the bolt threads and under the bolt heads.
FASTENER 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.
4. Install the cylinder head bolts using the installation and tightening sequence shown.
TIGHTEN
- In sequence (Figure 2), tighten all of the cylinder head bolts to 25 Nm (20 lb ft).
- In sequence (Figure 2), tighten all of the cylinder head bolts to 75 Nm (55 lb ft).
- In sequence (Figure 2), retighten all of the cylinder head bolts to 75 Nm (55 lb ft).
- In sequence (Figure 2), tighten all of the cylinder head bolts and additional 90 degrees - 100 degrees (1/4 plus turn).
LEFT SIDE
1. Remove intake manifold. Refer to, Intake Manifold/Service and Repair. Service and Repair
2. Remove fuel injection lines from injection pump.
3. If equipped with cruise control, remove cruise control transducer.
4. If equipped with A/C, remove upper fan shroud and A/C compressor belt.
5. Raise vehicle, then disconnect exhaust pipe at manifold flange.
6. If equipped with A/C, remove A/C compressor brace from exhaust manifold.
7. Remove exhaust manifold.
8. Remove power steering pump lower adjusting bolts.
9. Disconnect glow plug wiring and temperature switch.
10. Remove injection lines from nozzles, then cap all openings. Lower vehicle.
11. If equipped with A/C, discharge system, disconnect A/C compressor suction and discharge lines, then remove A/C compressor.
12. Remove power steering pump upper attaching bolt and position pump aside.
13. Remove stud from dipstick tube front bracket, then remove oil filler tube upper bracket.
14. Remove glow plug controller and bracket, then remove glow plug relay.
15. Disconnect T.V. cable.
16. Disconnect oil pressure switch and loom, then remove loom bracket.
17. Remove vacuum line clip attaching bolt from head.
18. Remove rocker cover bolts, then disconnect fuel return line bracket.
19. Remove rocker cover, then remove rocker arm assemblies and pushrods. Prior to removing pushrods, mark upper end as an aid during reassembly. Failure to identify pushrods could result in incorrect installation, leading to premature wear or damage.
20. Drain cooling system, then remove air cleaner resonator and bracket.
21. Remove transmission fill tube bracket nut, then position tube aside.
22. Disconnect heater, radiator and bypass hoses at coolant crossover, then remove crossover.
23. Remove generator upper mounting bracket.
24. Remove cylinder head bolts, then the cylinder head.
25. Reverse procedure to install, noting the following:
IMPORTANT:
- The cylinder head torquing sequence has been revised. The new procedure incorporates torque angle in the final tightening sequence, similar to the current crankshaft and bearings installation procedure. For all model years of the 6.5L engine, use the information provided in this bulletin.
- Make sure that the block gasket surfaces are clean.
- The head gasket material is soft. Handle the gasket with care. Make sure the gasket surface is not creased or dented.
- Do not use a sealer on the Head Gasket. The head gasket is made with sealant on the gasket surface. Additional sealer may cause leakage or malfunction. In addition, some sealers may attack the initial sealant on the gasket.
1. Install the cylinder head gaskets to the block, over the cylinder head dowel pins.
Cylinder Head Bolt Tightening Sequence:
2. Install the cylinder heads to the block, over the cylinder head gaskets and the cylinder head dowel pins.
3. Apply thread sealant GM P/N 12345382 or equivalent, to the bolt threads and under the bolt heads.
FASTENER 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.
4. Install the cylinder head bolts using the installation and tightening sequence shown.
TIGHTEN
- In sequence (Figure 2), tighten all of the cylinder head bolts to 25 Nm (20 lb ft).
- In sequence (Figure 2), tighten all of the cylinder head bolts to 75 Nm (55 lb ft).
- In sequence (Figure 2), retighten all of the cylinder head bolts to 75 Nm (55 lb ft).
- In sequence (Figure 2), tighten all of the cylinder head bolts and additional 90 degrees - 100 degrees (1/4 plus turn).