The fuel filter on the 1994 Ford F150 is located under the bed of the truck on the driver's side. It is mounted to the chassis in the fuel line. It is an in-line fuel filter. The new fuel filter should have an arrow showing the direction of the fuel flow. The arrow should always point toward the front of the vehicle. Fuel filters should be replaced every 30,000 miles as part of regular maintenance.
Park the truck on a level surface. Turn off the truck's ignition and set the parking brake. Open the hood and lift the cover off the relay box located near the driver's side fender well. Look on the inside of the cover for the diagram that indicates the relay for the fuel pump. Remove the relay and set it aside. Crank the engine over three or four times to relieve the fuel pressure in the system. The truck will not start.
Clean the area of the quick-disconnects on the fuel filter and fuel line with a rag. Install the fuel filter disconnect tool over the quick-release between the fuel filter and the line. Remove the fuel line from the filter. Repeat for the other side of the fuel filter. Unbolt the fuel filter bracket, using a socket, and remove the fuel filter.
Install the new fuel filter in the bracket and tighten the bolts, ensuring the arrow on the filter is pointing toward the front of the truck. Push the fuel lines onto the fuel filter until they snap into place. Plug the fuel filter relay back in. Start the truck and check for fuel leaks.
