WARNING: Never remove the radiator cap under any conditions while the engine is operating. Failure to follow these instructions could result in damage to the cooling system or engine and/or personal injury. To avoid having scalding hot coolant or steam blow out of the cooling system, use extreme care when removing the radiator cap from a hot cooling system. Wait until the engine has cooled, then wrap a thick cloth around the radiator cap and turn it slowly to the first stop. Step back while the pressure is released from the cooling system. When it is certain all the pressure has been released, press down on the pressure cap (still with a cloth), turn and remove. Remove pressure relief cap following described precautions.
Drain engine coolant.
Disconnect the negative battery cable.
Raise vehicle on hoist.
Disconnect the block heater power cable from the block heater.
Loosen the screw and back the screw out slowly until a slight resistance is felt.
CAUTION: Use extreme care to prevent scratching the cylinder block bore, as this will result in coolant leaks.
CAUTION: Discard any block heater which has been previously installed. Reinstalling a block heater will result in coolant leaks.
NOTE: If necessary, pry the block heater out of the cylinder block using a screwdriver where indicated.
Remove block heater from cylinder block.
Clean the inside diameter of the cylinder block hole machined surface and the hole entrance. Check the machined surface of the hole to be sure it is free of nicks, scratches and porosity.
Apply a liberal amount of Motorcraft Premium Engine Coolant VC-4-A (CXC-10 in Canada, VC-5 in Oregon) or equivalent meeting Ford specification ESE-M97B44-A to the block heater O-ring and the cylinder block bore.
CAUTION: Never use RTV or any type of sealer on the block heater O-ring or cylinder block bore. This will result in coolant leaks.
Install a new block heater into the cylinder block bore with the power cable connector at the 3 o'clock position. Fully seat the block heater into the block.
CAUTION: Do not overtighten the block heater screw. This will distort the block heater body and result in coolant leaks.
CAUTION: If the block heater spins in the cylinder bore more than 1/16 turn while the tightening the screw, remove and discard the heater. Attempting to spin the heater back into location will stretch the O-ring and result in coolant leaks.
Secure the block heater in the 3 o'clock position by hand and tighten the screw.