1. Drain coolant level below upper radiator hose and thermostat housing.
2. Disconnect lower radiator, coolant recovery and engine return hoses at thermostat housing, then remove two thermostat housing retaining bolts.
3. Remove O-ring seal and thermostat from thermostat housing.
4. Inspect O-ring for damage and replace if necessary.
5. Reverse procedure to install. Tighten to 7-8 ft lb .