Engine Coolant Thermostat Housing Replacement 4.8L, 5.3L, and 6.0L Engines

Important: The thermostat is not serviceable separately. The thermostat housing (water pump inlet) and thermostat must be replaced as an assembly.

1. Remove the radiator outlet hose. Refer to Radiator Outlet Hose Replacement .
2. Remove the water pump inlet bolts.
3. Remove the water pump inlet from the water pump.

1. Install the water pump inlet to the water pump.

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.

2. Install the water pump inlet bolts.

Tighten
Tighten the bolts to 15 N·m (11 lb ft).

3. Install the radiator outlet hose. Refer to Radiator Outlet Hose Replacement .