Diesel fuel has different properties in cold weather as opposed to gasoline. During extremely cold temperatures, diesel fuel can gel, affecting its ability to flow freely. This can cause problems with the 7.3 liter diesel engine in your 1999 F-250. Fuel gelling is usually not a problem in these trucks, as there is a heating element in the bottom of the fuel filter housing. Replace a faulty fuel heating element to ensure your truck can handle the coldest of temperatures.
install a memory saver to the vehicle, using the memory saver's instructions as a guide. Loosen the clamp on the negative battery cable on the passenger side battery with a wrench. Use a twisting motion and lift the cable straight up. Push the cable aside where it will not unintentionally come into contact with the negative battery terminal. Disconnect the negative battery cable on the driver side of the truck in the same manner.
Remove the two nuts from the black plastic trim cover on top of the engine with a socket, extension and ratchet wrench. Lift the cover straight up, then flip it over to reveal the fuel filter housing cover. Note that a wiring clip will still be attached to the passenger side of the cover preventing its total removal.
Place a drain pan under the front of the engine. Rotate the yellow drain valve lever on the back side of the fuel filter housing towards the passenger side of the truck. Allow the fuel in the bowl of the filter housing to drain into the pan. Close the drain valve once the fuel bowl has finished draining. Remove the drain pan from under the truck.
Twist off the plastic cover of the fuel filter housing with a large pair of slip-lock pliers or an oil filter wrench in a counterclockwise direction. Place the cover aside. Do not loose the rubber gasket on the underside of the cover.
Pull the fuel filter straight up and out of the fuel filter housing. Place the filter on a clean rag if you wish to reuse it, or discard it if you wish to install a new filter.
Pull the wiring connector on the heating element in the bottom of the fuel filter housing apart by hand. Remove the two element retaining screws with a Torx screwdriver. Lift the element straight up from the fuel filter mounting shaft. Remove the element from the housing and discard it.
Position the large hole in the replacement heating element over the fuel filter mounting shaft in the fuel filter housing. Line up the two mounting holes in the element bracket with the threaded holes in the bottom of the housing. Thread the two screws into the mounting holes and tighten them with a Torx screwdriver. Push the wiring connector on the element into the connector in the housing until they snap together.
Push the fuel filter over the shaft in the housing until it is fully seated. Replace the cover and tighten it until the gasket makes contact with the top of the housing. Replace the trim cover and tighten the two nuts.
Replace and tighten the negative battery cables. Remove the memory saver. Turn the ignition key on without starting the engine and wait a few seconds so that fuel will pump into and fill the fuel filter housing. Turn the key off. Start the engine and allow it idle. Check for leaks and tighten the housing cover, if necessary.
