Hummer H2. Manual — part 1823

If the valve lifter shows wear, inspect the engine block lifter bores for wear or damage.

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Flat spots on the roller (4)

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Loose or damaged pin (5)

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Plugged oil hole (6)

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Worn or damaged roller bearing

The roller should rotate freely with no binding or roughness.

Fig. 469: Valve Lifters & Lifter Guides
Courtesy of GENERAL MOTORS CORP.

5. Inspect the valve lifter guides for the following conditions:

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For cracks or damage

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Excessive wear in the lifter mounting bores

CYLINDER HEAD DISASSEMBLE

Tools Required

2004 Hummer H2

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2

J 8062 Valve Spring Compressor - Head Off. See Special Tools and Equipment .

2004 Hummer H2

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2

Fig. 470: Cylinder Head Components
Courtesy of GENERAL MOTORS CORP.

1. Remove the spark plugs from the cylinder heads.

IMPORTANT:

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Remove the spark plugs from the cylinder head with the components
at room temperature.

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Mark, organize, or sort the cylinder head components for assembly.
Return the components to their original location during assembly.

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Do not remove the cylinder head expansion plugs (226) unless
service is required.

2004 Hummer H2

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2

Fig. 471: Compressing Valve Spring Using J 8062
Courtesy of GENERAL MOTORS CORP.

2. Use the J 8062 in order to compress the valve spring. See Special Tools and Equipment .

2004 Hummer H2

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2