Thermostat: Service and Repair

Thermostat Replacement (6.6L (LLY) Engine)
Removal Procedure





1. Remove the water outlet.
2. Remove the bolt for the fuel line bracket.
3. Remove the fuel line bracket.
4. Remove the thermostat housing cover bolts.
5. Remove the thermostat housing cover.
6. Remove the thermostats and seals.

Inspection Procedure
1. Inspect the thermostats for sticking, cracks, and/or leakage of wax.
2. Replace the thermostats if damage is found.
3. Clean the thermostat housing and thermostat housing cover sealing surfaces.

Installation Procedure





1. Install the thermostats and seals to the thermostat housing . The rear thermostat (4) has 2 vent valves. Install with the vent valves towards the rear of engine.





2. Install the thermostat housing cover.

Notice: Refer to Fastener Notice in Service Precautions.

3. Install the thermostat housing cover bolts.
^ Tighten the bolts to 21 Nm (15 ft. lbs.).
4. Install the fuel line bracket.
5. Install the fuel line bracket bolt.
^ Tighten the bolt to 21 Nm (15 ft. lbs.).
6. Install the water outlet tube.