The Ford F-150 is one of the easier vehicles to work on, due to its high clearance and large engine well. The gas tank in the F-150 is located at the rear of the truck, below the payload bed. Two large retaining straps hold the tank in place. If the tank becomes contaminated or damaged, you will need to remove it for cleaning and repair or replace it. Make sure the tank is empty before attempting to replace it.
Slide the floor jack under the rear of the F-150 and raise the jack up until the head is touching the bottom of the gas tank.
Open the fuel door and disconnect the fuel filler neck flange with the socket set. If your F-150's gas tank has a removable filler neck, you do not need to do this. If the tank and filler neck are one assembly, depending on the year and configuration of your F-150, you may need to access the flange fasteners from underneath.
Unbolt the fuel tank retaining straps and allow them to hang. Lower the fuel tank slowly with the floor jack, while your helper holds the tank steady. Once it has come down a few inches, reach in and disconnect the wiring harness to the fuel pump and the fuel lines. Newer-model F-150s may require you to disconnect the fuel filler neck during this step also.
Lower the tank the rest of the way down, making sure none of the lines or filler neck are interfering with the tank removal, and slowly guide the tank backwards and out from underneath the F-150. You may need your helper for this.
Pick the tank up off the jack and set it aside. Wrap the rag around the tip of the screwdriver and place the tip on the fuel pump retaining flange. Tap the screwdriver with the rubber mallet to loosen the ring so you can remove the fuel pump. Insert the pump into the new tank, with a new o-ring.
Place the new tank on the jack and roll it underneath the F-150. Raise the tank up until you can reconnect the fuel lines, wiring harness and filler neck. Raise the tank all the way and then pull the retaining straps back into position and reinstall the retaining strap bolts.
Reinstall the filler neck flange in reverse of how you removed it, if you needed to remove it at all.
