Chevrolet Silverado / GMC Sierra. Service manual — part 379

1. Remove the seals (308) from the pipe and covers.

Fig. 510: View Of Coolant Air Bleed Pipe Components
Courtesy of GENERAL MOTORS CORP.

2. Clean the pipe and covers in solvent.

again. Upon installation of the pipe and covers, install NEW
seals.

CAUTION: Refer to Safety Glasses and Compressed Air Caution .

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2

3. Dry the pipe and covers with compressed air.

4. Inspect the pipe and covers for restrictions within the pipe (1) or damaged sealing surfaces

(2, 3).

WATER PUMP CLEANING AND INSPECTION

Fig. 511: View Of Water Pump
Courtesy of GENERAL MOTORS CORP.

1. Remove the old gasket from the water pump sealing surfaces. Refer to Replacing Engine

Gaskets.

2. Clean all excess dirt and debris from the water pump housing.

3. Inspect the water pump for the following conditions:

Gasket and hose sealing surfaces for excessive scratches or gouging

Restrictions within the internal coolant passages

Excessive side-to-side play in the pulley shaft

Leakage at the water inlet housing or rear cover

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2

Leakage at the water pump vent hole

A stain around the vent hole is acceptable. If leakage, dripping, occurs with the engine
running and the cooling system pressurized, replace the water pump.

Wear or damage in the belt tracking area of the pulley

THREAD REPAIR

Tools Required

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

J 42385-200 Common Thread Repair Kit. See Special Tools.

J 42385-300 Fixtures and Hardware Kit. See Special Tools.

General Thread Repair

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2

Fig. 512: View Of Bushing Type Insert & Base Material
Courtesy of GENERAL MOTORS CORP.

The thread repair process involves a solid, thin walled, self-locking, carbon steel, bushing type
insert (1). During the bushing installation process, the driver tool expands the bottom external
threads of the insert into the base material (2). This action mechanically locks the insert in place.
Also, when installed to the proper depth, the flange of the insert will be seated against the
counterbore of the repaired hole.

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2