A thermostat control the flow of a car's anti-freeze through the engine. The thermostat is usually easy to locate within the engine compartment, and is easily replaced if it fails or is defective. Seal the housing when you install a new thermostat; this prevents leakage of engine coolant.
Park your car. Turn off the engine and allow it to cool. Follow the top radiator hose from the radiator to the thermostat housing.
Unscrew the clamp, and remove the radiator hose from the housing. Some engine coolant might leak out; this is normal.
Remove the bolts from the thermostat housing; lift off the top of the housing. Remove and discard the old gasket and thermostat.
Clean the surface on both halves of the housing. This surface must be completely clean and flat to ensure you have a proper seal.
Apply a small amount of gasket sealer to the gasket, and install the gasket on the housing in the engine compartment. Sit the new gasket in the housing.
Place the other half of the gasket housing in place. Insert and tighten the bolts until the housing is securely in place.
