The thermostat in a 2000 Ford F-150 regulates the engine temperature so it does not overheat. A malfunctioning thermostat may stick and block the coolant from going into the engine. That may cause the truck engine to overheat and could cause serious engine troubles. The thermostat is located in a sealed housing, and you must gain access to the housing to replace the thermostat.
Open the hood of the F-150 to access the engine compartment. Locate the upper radiator hose.
Follow the hose to the engine. The hose is located behind and to the right of the alternator.
Unscrew the two bolts holding the housing in place with a socket wrench. Pull the thermostat housing cover away from the thermostat housing.
Scrape the gasket away from the mating surfaces of the thermostat housing. Ensure all black material is scraped away.
Pull the used thermostat out of the housing by hand. Replace it with the new thermostat. The end of the thermostat with the spring attached goes in first.
Place a new gasket onto the mating surface. Bolt the hose inlet piping over the gasket with a socket wrench.
Unscrew the radiator cap, and inspect the fluid level. The coolant should be visible at the neck of the radiator.
Add coolant, if necessary. Start the truck engine, and allow it to warm up. The coolant level may drop. Fill the radiator with coolant as needed.
Put the pressure cap back on to the radiator. Close the hood. Turn the vehicle off.
