The 2002 Ford Explorer uses a thermostat to regulate the coolant system. The thermostat is designed to open when the engine starts to get hot. The coolant will flow through the engine and absorb the excess heat, cooling the engine down. A faulty thermostat will stick and cause the coolant to back up in the radiator. This can cause the engine to overheat and create serious engine troubles.
Ensure the truck is turned off and parked on a flat and level surface. Open the hood for access to the engine compartment. Locate the upper radiator hose.
Trace the hose to the thermostat housing. The hose will be clamped to the inlet pipe of the thermostat housing.
Unscrew the hose clamp with a flat-tip screwdriver. Pull the hose off of the pipe.
Unbolt the thermostat housing with a socket wrench. Pull the thermostat housing cover away from the housing.
Pull the thermostat out of the housing. Replace with a new thermostat. Ensure the spring end is loaded first.
Scrape the old gasket material off the mating surfaces with a razor scraper. Ensure all the black material is removed before installing the new gasket.
Place the new gasket on to the bottom mating surface. Bolt the cover over it with a socket wrench.
Push the hose onto the inlet pipe. Pull the hose clamp over the inlet pipe and tighten with a flat-tip screwdriver.
Twist the radiator cap counterclockwise to pull off the radiator. Start the truck and allow it to warm up. Once the truck has warmed up, the thermostat will open to release coolant. Fill with pre-mixed coolant until the radiator cannot hold any more. Tighten the cap onto the radiator. Turn the truck off. Close the hood.
