Fist produced in 1968, Ford’s 302 V8 engine came in a variety of different configurations, but every 302 used the same cooling design. The radiator fluid passes through each cylinder head and into the intake manifold. Between the intake manifold and the radiator is a single thermostat. When the engine is warm, the thermostat opens and allows the fluid to enter the radiator where it is cooled. A defective thermostat usually fails to open, quickly resulting in overheating. Fortunately, the 302’s thermostat is at the front of the engine and typically takes only about 15 minutes to replace.
Release the radiator cap from the center of the top of the radiator by rotating the cap in a counterclockwise direction.
Locate the petcock plug on the driver’s side of the base of the radiator, then position a large container underneath the petcock plug.
Loosen the petcock plug with a wrench until radiator fluid begins to drain out of the plug and into the container. Close the plug with the wrench once the radiator fluid falls below the upper radiator hose, as determined by looking into the radiator through the cap opening.
Disconnect the water-pump hose and the top radiator hose from the thermostat housing. Each hose is secured with a clamp. Loosen the bolt on the clamp with a nut driver and pull both hoses off the housing.
Remove the two securing bolts from the sides of the thermostat housing, then pull the housing off the engine. Pull the thermostat out of the engine. Note that the large metal spring on one side of the thermostat faces the engine.
Insert the new thermostat into the engine with the thermostat’s spring facing towards the engine.
Apply gasket sealant to each side of a new thermostat gasket and press the gasket onto the back of the thermostat housing.
Place the thermostat housing over the thermostat and tighten the housing’s two securing bolts with a wrench.
Slide the water-pump and upper radiator hoses onto the thermostat housing and tighten the clamp on each hose with a nut driver.
Pour the radiator fluid that was drained back into the radiator and twist the radiator cap onto the radiator.
