Replacing The Fuel Tank On An '03 F-150: Step-By-Step Guide

Changing the fuel tank on a 2003 Ford F-150 is a complex process that requires careful attention to safety precautions. The first step is to ensure the fuel tank is almost empty, either by siphoning the gas or driving the truck until the tank is nearly empty. Next, it is important to relieve the pressure in the fuel system and disconnect the fuel lines at the tank while wearing safety glasses. One can then break the nuts loose at each end of the mounting straps and use a floor jack or ratchet straps to lower the tank. After this, the filler hose can be removed, and the tank can be completely lowered and disconnected. Finally, the old tank can be replaced with a new one, and the truck can be reassembled.

Disconnect the battery cables

Disconnecting the battery cables is an important step when changing the fuel tank on a 2003 F-150. This is a safety measure to eliminate any chance of a spark and to prevent the fuel pump from running while you work.

Before disconnecting the battery, you should ensure that your F-150 is on a flat and safe surface and that the engine is off. You will also need to remove the negative battery cable first.

To disconnect the battery cables, you will need to locate the battery. On the F-150, the battery is typically located in the engine compartment, under the hood of the truck. Once you have located the battery, you will need to identify the negative battery cable. The negative cable is usually black and is connected to the negative terminal on the battery, which is often marked with a "-" symbol.

To disconnect the cable, you will need to loosen the nut or bolt that secures the cable to the battery terminal using a wrench or socket. Make sure to wear safety gloves to protect your hands. Once the nut or bolt is loosened, you can carefully remove the cable from the battery terminal.

It is important to note that you should never disconnect the positive cable first, as this can create a dangerous spark. Additionally, be careful not to let the negative cable touch any metal parts of the truck while it is disconnected, as this could also create a spark.

After you have completed the fuel tank replacement, you can reconnect the negative battery cable by securing it to the negative terminal and tightening the nut or bolt.

Remove the filler neck and hoses

To remove the filler neck and hoses, you will need to:

Remove the filler neck mounting hardware:

Use a screwdriver to loosen the two hose clamps holding the filler tube and vent tube. Loosen the two hoses slightly so they can be removed later.

Disconnect the filler neck:

Separate the filler neck from the bed of the truck. This will involve loosening the clamp connecting the filler neck to the bed.

Remove the fuel filler cap:

Take off the cap that covers the filler neck.

Lower the fuel tank:

Use a floor jack or ratcheting straps to lower the tank slowly. Ensure that the fuel tank is almost empty before attempting this step. As the tank is lowered, you will be able to access and disconnect the hoses and fuel lines.

Disconnect the hoses and fuel lines:

There will be two filler hoses, two fuel lines, and three smaller hoses connected to sensors. Use a screwdriver to release the clamps holding these hoses in place. For the fuel lines, you will need a 3/8" fuel line disconnect tool or a homemade tool made from a stiff piece of wire.

Once all the hoses and lines are disconnected, slowly lower the fuel tank to the ground.

Clean and prepare the new tank:

Before installing the new tank, transfer the sensors, fuel pump assembly, and any other reusable components from the old tank to the new one. Ensure that the sensors and fuel pump assembly are correctly aligned and secured.

Lower the tank

Lowering the fuel tank of a 1997-2003 Ford F-150 is a complex process that requires careful attention to safety. Here is a detailed, step-by-step guide:

Firstly, ensure your F-150 is parked on a flat and safe surface, with the engine turned off. Safety should be a priority, so wear safety glasses and make sure there is no smoking or open flames near the tank or truck. It is also important to disconnect the battery cables to prevent any chance of a spark and to stop the fuel pump from running.

Next, you will need to siphon the gas from the tank. Use a clear hose and an air pump to do this, ensuring the tank is empty or almost empty.

Now, you need to elevate your truck. Use a jack to raise the vehicle to a height of at least 18 inches from the ground. Place the jack in the grooves along the frame of the truck. If your truck is already lifted, you may not need to do this step.

Once the truck is safely elevated, crawl underneath and locate the heat shield. You will see two sets of bolts: one set holds the heat shield, and the other the fuel tank. Use an impact wrench to remove the bolts holding the heat shield. As you remove the bolts, support the heat shield with your knee so it doesn't fall on you. Once removed, set the heat shield aside.

Now, grab two floor jacks and place them under the fuel tank. Raise the jacks just enough to support the tank. It is recommended to place some soft padding between the jacks and the tank to avoid any damage.

Use your impact wrench again to remove the four long bolts from the fuel tank. Once the straps are loosened, carefully lower and twist them off. Set the straps and bolts aside.

At this point, the fuel tank should only be supported by the jack stands. Ask an assistant to slowly lower the stands while you hold the tank. The front end will not drop immediately due to the fuel fill line connection, so you will need a 1/4 inch hex socket to disconnect this.

Once the fuel fill line is disconnected, your assistant can continue to slowly lower the jack stands, allowing you to pull the fuel tank out from under the truck.

This process is intricate and requires a good level of mechanical skill. Take your time and follow each step carefully to ensure a successful fuel tank removal.

Disconnect the fuel lines

Disconnecting the fuel lines is a crucial step when changing the fuel tank on a 2003 F-150. It is important to note that there are two fuel lines that need to be disconnected, and they can be identified by their different sizes.

To disconnect the fuel lines, you will need a fuel line disconnect tool or a similar tool that can be wrapped around the hose and pushed into the connector. This tool can be purchased at most auto parts stores, or you can make your own using a stiff piece of material, such as a plastic wire clamp.

First, locate the fuel lines coming from the fuel pump assembly. They will be connected to the fuel pump module with retaining clips. You may need a flat-head screwdriver to help release these clips if they are difficult to remove. Once the clips are released, carefully pull the fuel lines away from the fuel pump assembly.

It is important to keep the fuel lines upright during this process to prevent any gas from spilling out. Additionally, be sure to catch any spilled gas with a suitable container and dispose of it properly.

After disconnecting the fuel lines, slowly lower the fuel tank to the ground using the straps or jacks that are supporting it. Once the tank is on the ground, you can proceed to remove the old fuel pump assembly and install the new one if you are replacing it.

If you are reconnecting the fuel lines to a new fuel pump assembly, be sure to coat the new gasket with a light layer of silicone lubricant to ensure a positive seal. Reattach the fuel lines, reconnect the electrical connector, and proceed to reinstall the fuel tank or truck bed, depending on your chosen method of access.

Remove the old tank

To remove the old fuel tank from your 03 F-150, first ensure that your vehicle is on a flat and safe surface, with the engine off. You will also need to drain the gas tank before making any repairs.

Next, jack up your truck to a height of at least 18 inches from the ground. Use a standard jack and place it in the groves along the frame of your truck. If your truck is already lifted, you may not need to do this.

Now, grab an impact wrench and crawl under the truck. Locate the heat shield, which is protecting the fuel pump. You will also notice two sets of bolts. One set holds the heat shield in place, and the other set holds the fuel tank in place. Remove the bolts holding the heat shield, and place your knee against it as you wiggle it free. Once it is free, set it aside.

Grab two floor jacks and place them underneath the fuel tank to support it as you remove its bolts. Be sure that the jacks are raised just enough to support the tank. It's a good idea to insert some soft padding between the jack stand and the tank to prevent damage.

Use an impact wrench to remove the four long bolts from the fuel tank. Once both straps are loosened, lower the straps and twist them off gently. Set the straps and bolts aside.

Now your fuel tank should be supported only by the jack stands. Ask a helper to slowly lower the stands while you hold the fuel tank. The front end won't drop right away because it is connected to the fuel fill line. You will need a 1/4 inch hex socket to remove this connection.

Once the fuel fill line is disconnected, your assistant can lower the jack stands further, and you should be able to pull the fuel tank out from under the truck.

Alternatively, you can remove the bed of the truck to access the fuel tank. This method may be preferable if you don't have the necessary tools, jack stands, or inclination to get under your truck. To do this, remove the bolts that are keeping the bed in place, disconnect the bed and tailgate lighting, remove the wire harnesses for the bed lighting and tail light plugs, and the fuel filler cap and fuel filler neck clamp. You will also need help from two strong friends to lift the bed off your truck.

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