The thermostatic radiator valve, also called the thermostat valve, is located at the opposite end of the upper radiator hose from the radiator. The thermostat valve sits under the thermostat housing at the end of the hose and can be accessed by detaching two bolts to remove the housing from the engine block. Replacing the thermostatic radiator valve is a job you can do in about an hour, saving money on labour costs by doing so.
Park your vehicle on level ground and turn off the engine. Allow the engine to cool down completely. Place a drain pan on the ground under the drain valve at the bottom of the radiator. Remove the radiator cap from the top of the radiator and set it aside.
Open the drain valve at the bottom of the radiator with a pair of pliers and let the radiator fluid drain out completely into the drain pan. Follow the upper radiator hose to where it connects to the engine. Locate the thermostat housing at the end of the upper radiator hose.
Detach the two bolts that secure the thermostat housing to the engine, using a socket wrench. Move the housing and the hose out of the way. Lift the thermostat valve off the engine with a small flathead screwdriver and discard the valve.
Remove any remaining gasket debris from around the thermostat housing and on the engine block where the valve sits, using a putty knife. Be careful not to knock any gasket material into the engine block.
Place a thin layer of gasket sealant around the face of the thermostat housing. Set the new gasket over the face of the housing on the sealant. Put the new thermostat valve over the hole on the engine block. Reattach the thermostat housing to the engine, over the new thermostat, with bolts.
Close the drain valve on the bottom of the radiator. Fill the radiator with a mixture of half coolant and half water. Attach the radiator cap to the top of the radiator.
Remove the drain pan from under the vehicle. Dispose of the coolant at your local recycling centre or automotive supply store.