To replace the fuel filter for a Ford 7.3 liter diesel engine, remove the fuel system cover, and release the fuel system bleed valve, then remove the fuel filter's cover, and replace the filter. Use a bucket to collect the fuel and water that drip from the bleed valve, and moisten the new o-rings with diesel fuel before closing the bleed valve and replacing the covers.
The tools needed for this task are a ratchet with assorted sockets and extensions, gloves and a drain pan or bucket. Working with fuel is dangerous, and protective eyewear is recommended. The fuel filter is located near the alternator on the 7.3 liter Ford diesel engine.
The fuel system cover is marked "Powerstroke 7.3L Turbo Diesel" and is attached by two nuts on its top. Place the drain pan under the fuel bleed valve on the ground, and turn the bleed valve, a yellow plastic lever, clockwise a quarter turn to release the pressure from the fuel system. Remove the bolt in the middle of the fuel filter cover, and remove the cover by turning it counter-clockwise, then remove the old fuel filter. Clean any debris out of the fuel bowl, and install the new fuel filter. Replace the fuel filter cover.
Turn the key in the ignition to the On position without starting the engine, to activate the fuel pump and prime the fuel injection system. Inspect the fuel lines for leaks and, if there are none, replace the fuel system cover.