WARNING: Do not stand in line with or near radiator fan blade when engine is running.
Drain the cooling system so that the coolant level is below the water thermostat.
Disconnect the heater return hose at thermostat housing located on the left front lower side of the engine (6007). Disconnect engine coolant temperature sensor (ECT sensor) (12A648) connector.
Remove upper radiator hose (8260).
CAUTION: Do not pry on water thermostat (8575) to remove.
Remove the coolant outlet housing retaining bolts. Pull the elbow away from the cylinder head (6049) or manifold sufficiently to provide access to the water thermostat. Remove the water thermostat and gasket.
CAUTION: The thermostat seal must be positioned on the water outlet connection before the water thermostat is installed. To prevent incorrect installation of the water thermostat, the water outlet connection casting contains a locking recess into which the water thermostat is turned and locked. Install the thermostat with the bridge section in the outlet casting. Turn the thermostat clockwise to lock it into position on the flats cast into the water outlet connection.
Clean the upper radiator hose connection, cylinder head and water outlet connection surfaces. Coat a new thermostat housing gasket with Perfect Seal Sealing Compound B5A-19554-A or equivalent meeting Ford specification ESE-M4G115-A. Position the thermostat housing gasket on the cylinder head opening.
NOTE: It is critical that the correct water thermostat installation alignment be made to provide coolant flow to heater. Insert and rotate water thermostat to the left or right until it stops in the water outlet connection housing, then visually check for full width of heater outlet tube opening to be visible within the thermostat port in assembly. This port alignment at assembly is required to provide maximum coolant flow to the heater.
Position the coolant water outlet connection against the cylinder head, intake manifold (9424) or water pump (8501). Install and tighten the retaining bolts to 20-30 Nm (14-21 ft lb).
Connect the upper radiator hose to water outlet connection.
Fill the cooling system with the recommended Premium Cooling System Fluid E2FZ-19549-AA or equivalent meeting Ford specification ESE-M97B44-A and water mixture. Check for leaks and proper coolant level after the engine has reached operating temperature.
NOTE: A coolant mixture of 50 percent ethylene glycol and 50 percent water is recommended to maintain best overall performance. To avoid damaging the radiator (8005), the ethylene glycol should not exceed 60 percent.