Ford 3C3Z-8575-AA
Thermostat Housing

The first step to service the 5.4L and 6.8L engine thermostat includes draining part of the cooling system fluid. First disconnect the upper radiator hose before removing the outlet connection by destroying its bolts. You should first discard the O-ring seal before you remove the coolant thermostat and its O-ring seal. The correct process for installing the coolant thermostat in the upper intake manifold includes using a new O-ring seal that must fit properly. Secure the cooling system outlet by attaching it to the upper intake manifold then install its connecting bolts. Reestablish the upper radiator hose before finishing the procedure by filling the cooling system.

The first step for servicing the thermostat of 5.4L and 6.8L engines involves draining all fluid from the engine cooling system. The second step involves taking out the air cleaner outlet pipe. Before working on the thermostat housing users need to disconnect the upper radiator hose from the housing. Set your workload by taking out the two bolts from the thermostat housing while placing it to the side and removing the thermostat before you discard the used O-ring. You need to apply metal surface prep between cleaning the mating surfaces before adding a fresh O-ring seal. Follow the removal procedure in reverse order to install the parts while tightening bolts to 10 Nm (89 inch lbs).

Use a new O-ring seal to position the coolant thermostat in the upper intake manifold.

Reconnect the upper radiator hose and fill the cooling system.

Remove the air cleaner outlet pipe.

Inspect and clean the mating surfaces with metal surface prep.