How do you replace the thermostat in a 1991 Ford Explorer?

Answer 1

With the hood open locate upper radiator hose. The one that runs from the top of radiator to top of engine. On the engine side you will see the hose secured to engine with some type of clamp. The hose is clamped to the thermostat housing. The thermostat is within that housing and the housing is secured by two or more bolts. Before taking the bolts out and removing thermostat be sure to remove some of the anti freeze from the radiator. (Do this when engine is cold and not too hot!) Make sure that you get a new gasket with the new thermostat and some silicone sealant. Be sure to remove all of the old gasket material as the new gasket will leak if you don't. Re-assemble all parts and put antifreeze back into radiator and idle till warm, add more antifreeze as needed!