Hummer H2. Manual - part 1871

Tools Required 

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J 42385-100 Head/Main Bolt Thread Repair Kit. See Special Tools and Equipment .  

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J 45059 Angle Meter. See Special Tools and Equipment .  

Fig. 640: Cylinder Head Locating Pins Installation Position 
Courtesy of GENERAL MOTORS CORP. 

CAUTION: Refer to Safety Glasses Caution in Cautions and Notices.

NOTE:

Clean all dirt, debris, and coolant from the engine block cylinder head bolt 

 

2004 Hummer H2 

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

  

1. Clean the engine block cylinder head bolt holes, if required. 

Thread repair tool J 42385-107 may be used to clean the threads of old threadlocking material. 

2. Spray cleaner GM P/N 12346139 (Canadian P/N 10953463), GM P/N 12377981 (Canadian P/N 

10953463) or equivalent into the hole.  

3. Clean the cylinder head bolt holes with compressed air. 

holes. Failure to remove all foreign material may result in damaged 
threads, improperly tightened fasteners or damage to components.

IMPORTANT:

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Do not use the cylinder head bolts again. Install NEW cylinder head 
bolts during assembly.  

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Do not use any type sealant on the cylinder head gasket, unless 
specified.  

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The cylinder head gaskets must be installed in the proper direction 
and position.  

 

2004 Hummer H2 

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

  

Fig. 641: 100 mm & 155 mm Bolts 
Courtesy of GENERAL MOTORS CORP. 

4. Measure the depth of the cylinder head bolt holes (1-10) and select the correct length bolts as required.  

5. Check the cylinder head locating pins for proper installation. 

IMPORTANT: First design engine blocks have different drill and tap depths using both 

medium length 100 mm (3.94 in) and long 155 mm (6.1 in) M11 cylinder 
head bolts. Second design engine blocks use only the medium length 100 
mm (3.94 in) bolt with a common drill and tap depth.

 

2004 Hummer H2 

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

  

Fig. 642: Cylinder Head Gasket Displacement Markings 
Courtesy of GENERAL MOTORS CORP. 

6. Inspect the displacement markings (1) on the gasket, for proper usage. 

 

2004 Hummer H2 

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