How to Change the Thermostat on an F250

The thermostat is a small but important component of the engine in the Ford F250. The F250 is a full-sized truck capable of carrying large payloads that can take a toll on the engine. As the temperature of the engine increases, the thermostat allows more fluid to flow through passages inside the engine block. As the engine temperature cools down, the thermostat starts to restrict the flow of coolant. If the thermostat malfunctions, the engine can overheat. When it fails, replace it immediately to avoid costlier engine repairs.

Locate the thermostat by following the upper radiator hose from the F250’s radiator to the connection at the intake manifold on the top of the engine. The hose is clamped to the thermostat housing.

Remove the hose from the thermostat housing by prying the clamp off with a pair of pliers and by pulling off the hose.

Remove the two bolts that secure the thermostat housing to the intake manifold. Lift the housing off the intake to expose the thermostat.

Lift the thermostat out of the intake and discard it.

Scrape the surface of the intake and the bottom of the thermostat housing with a metal scraper. Wipe the surface of the intake manifold with a towel.

Place the new thermostat into the intake manifold. The end of the thermostat with the spring goes into the intake manifold while the end with the valve is covered by the housing.

Place the thermostat gasket onto the surface of the intake manifold, place the housing on top of the gasket and secure both with the bolts.

Place the hose back onto the intake manifold and secure it with the clamp.