How to Seal a Thermostat
- 1). Park your car. Turn off the engine and allow it to cool. Follow the top radiator hose from the radiator to the thermostat housing.
- 2). Unscrew the clamp, and remove the radiator hose from the housing. Some engine coolant might leak out; this is normal.
- 3). Remove the bolts from the thermostat housing; lift off the top of the housing. Remove and discard the old gasket and thermostat.
- 4). Clean the surface on both halves of the housing. This surface must be completely clean and flat to ensure you have a proper seal.
- 5). 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.
- 6). Place the other half of the gasket housing in place. Insert and tighten the bolts until the housing is securely in place.
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