Replacing Your Diesel Fuel Tank: A Step-By-Step Guide

Replacing a fuel tank is a complex process that requires careful attention to safety precautions. While modern cars often feature plastic fuel tanks, older vehicles used metal tanks that are prone to failure over time. Before attempting to replace a fuel tank, it is crucial to drain the tank completely and store the fuel in a safe container. This task should be performed in a well-ventilated area to avoid inhaling toxic fumes, which can be dangerous and flammable. It is also important to have a fire extinguisher nearby in case of any accidents. When removing the tank, make sure to unclip all fuel lines and take note of the various nuts and bolts to facilitate easier reassembly. It is recommended to replace any rusty or corroded parts, such as breather lines, fuel line clips, and fuel tank straps, to ensure the safety and integrity of the fuel system.

Drain the old fuel tank

Before you can install a new tank, you must remove the old one. The first step in this process is to drain the fuel from the old tank. Here is a step-by-step guide:

Step 1: Prepare the necessary tools and equipment

It is important to have the right tools and equipment before starting. You will need items such as strap bolts, wrenches of various sizes, screwdrivers, a jack, jack stands, a pump for removing the fuel, fuel-rated containers for the removed fuel, rags, and a fire extinguisher.

Step 2: Find a suitable work area

Locate the vehicle on a flat surface, preferably a concrete driveway. If a concrete driveway is not available, hard, compacted soil can also be used.

Step 3: Access the fuel tank

Depending on the vehicle, the fuel tank may be located at the rear or under the hood. Refer to the vehicle's owner's manual for the precise location.

Step 4: Remove the fuel tank cap

Take off the fuel tank cap to allow air to enter the tank and facilitate the draining process. Removing the cap will also prevent a vacuum from forming inside the tank, making fuel removal easier.

Step 5: Choose a suitable draining method

• There are several methods for draining a fuel tank, and the choice depends on the vehicle's make and model. Here are some popular methods:
• Siphoning: This is the most common method. Use a siphoning kit with a hose and a hand pump. Insert the hose into the fuel tank, reaching the bottom. Then, use the pump to create suction and draw out the fuel into a container.
• Electric fuel pump: If your vehicle has an electric fuel pump, locate the fuel pump fuse or relay in the fuse box and remove it. Turn on the ignition without starting the engine to activate the pump. Once the tank is empty, turn off the ignition and replace the fuse or relay.
• Gravity draining: If you have a car lift or jack stands, you can use gravity to your advantage. Position the vehicle on the lift or stands, locate the fuel tank drain plug, and remove it. The fuel will flow out into a container below.

Step 6: Dispose of the drained fuel

Properly disposing of the drained fuel is crucial. Do not pour it down the drain or into the soil, as it can harm the environment. Take the fuel to a hazardous waste disposal site or a recycling centre for safe disposal.

Remove the fuel lines

Removing the fuel lines is a crucial step in replacing a diesel fuel tank. Here is a detailed guide on how to safely and effectively complete this task:

Locate the Fuel Lines: Begin by identifying the fuel lines connected to the diesel fuel tank. Typically, there are two fuel lines attached to the tank. The smaller line at the bottom of the tank carries fuel to the engine, while the larger line at the top is used for filling the tank with diesel. There may also be a third line, known as an air-line, which helps regulate pressure as the fuel moves through the tank.

Gather the Necessary Tools: Before starting, ensure you have the right tools on hand. A flat-head screwdriver or a specialised tool like a quick-connect tool can be useful for detaching the fuel lines. These tools are readily available at most auto parts stores.

Detach the Fuel Lines: To remove the fuel lines, start by pressing the little plastic buttons or tabs on the connectors. These tabs are usually blue or white and need to be pushed in before pulling the lines off. Be cautious, as they can be challenging to remove, especially if you live in an area with snow, ice, or salt, which can make them more susceptible to corrosion. If the lines are difficult to detach, consider using a tool specifically designed for internal clip designs. Alternatively, a screwdriver can be gently used to pop the lines off.

Be Organised: As you work, bag and label any nuts and bolts you remove, making notes or taking pictures to remember their original positions. This will make reassembly much easier and ensure you don't misplace any essential components.

Safety Precautions: Remember to work in a well-ventilated area when dealing with fuel lines. Even after draining the tank, fumes can be hazardous and flammable. Keep a suitable fire extinguisher (a Class B extinguisher is recommended for diesel fuel) nearby in case of any sparks or accidental ignitions.

By following these steps, you can effectively remove the fuel lines from your diesel fuel tank, preparing you for the next stages of the replacement process. Always refer to manufacturer guidelines or seek professional advice if you have any concerns or uncertainties during this complex procedure.

Prepare tools and equipment

Before you begin, make sure you have all the necessary tools and equipment for the task. There are many different fasteners, clamps, and connections that must be removed or loosened to access and remove the fuel tank. Here is a list of the tools you will need:

• Strap bolts: You will need an open-end wrench set, including 1⁄2 or 9⁄16 inch (1.3 or 1.4 cm) or 12, 13, or 14 mm sizes.
• Screwdrivers: Have both slotted and Phillips screwdrivers for hose clamps and other screws.
• Fuel line fittings: You may need special tools for disconnecting the fuel line fittings.
• Jack and jack stands: Use these to lift and support the vehicle.
• Pump: A pump is required to remove the fuel from the old tank.
• Fuel containers: Ensure you have fuel-rated containers to safely store the fuel that is removed from the tank.
• Rags: Have some rags or towels handy to wipe up any spills or excess fuel.
• Fire extinguisher: It is crucial to have a Class B fire extinguisher nearby in case of emergencies.
• Work mat or plywood: Place something comfortable and protective underneath the car to lie on while working and to catch any falling nuts, bolts, or washers.
• Adapter: If your car has a drainpipe or filler hose, you may need an adapter to connect the pump.
• Compressor or compressed air: Use this to blow off debris from fuel lines and wiring connectors.
• Brush: A small stiff brush can help loosen accumulated debris on the fuel lines and connectors.
• Filler neck tools: If your filler neck is a two or three-piece assembly, you may need a clamp and a neoprene hose.
• Eye protection and gloves: It is important to wear protective gear when working with fuel and chemicals.

It is also recommended to have an assistant to help with handing tools, responding to emergencies, and managing the weight of the fuel tank.

Drain the fuel

Before you can install a new tank, you must first drain the fuel from the old tank. This is a crucial step in the process of replacing a fuel tank, as it ensures that no fuel is left behind, which could pose a safety hazard. Here is a detailed guide on how to effectively drain the fuel:

• Locate the Drain Valve: Many modern fuel tanks are equipped with a small stop valve that allows for easy drainage. This valve is usually located on the body of the fuel tank. If your vehicle has this feature, simply loosen the valve and let the fuel flow into a fuel can or another suitable container. Ensure you are working in a well-ventilated area to avoid inhaling toxic fumes.
• Use a Drain Hose: If your vehicle does not have a fuel tank valve, you will need to remove one of the fuel lines to drain the tank. Place a hose into the tank and suck on the other end to start the flow of fuel. This method requires caution, as it carries a risk of inhaling toxic fumes or getting fuel in your mouth. Always have a container ready to collect the fuel.
• Use a Pump: Another option is to use a manual pump or an air compressor to drain the fuel. For this method, you will need a pump, a fuel tank adapter, and a fuel line. Connect the fuel line to the tank adapter and the adapter to the pump. Once set up, start the pump to force the fuel out of the tank. Keep a container nearby to collect the drained fuel.
• Direct Drainage: Some fuel tanks have a drain plug located near the bottom of the tank. Use a wrench to loosen this plug, allowing the fuel to drain out. Have a wide-mouthed container, such as a basin, ready to catch the fuel. This method may not work for all vehicles, so be sure to consult your vehicle's manual or a mechanic if you are unsure.

No matter which method you choose, always exercise caution when handling fuel. Work in a well-ventilated area, wear protective gear, and have a fire extinguisher nearby in case of emergencies. Ensure that you have the necessary tools and equipment before beginning the drainage process.

Remove the tank

Removing a fuel tank is a big job, but it's important to know how to do it safely. Here is a step-by-step guide on how to remove the tank:

Firstly, completely drain the tank. This is important as fuel has a propensity to ignite. Place a container or pan underneath the drainage plug and loosen the valve, letting the fuel run out. If your car doesn't have a fuel tank valve, you'll need to remove one of the fuel lines to drain the tank. Make sure you do this responsibly and store the fuel in the correct container.

Next, identify the fuel lines. There should be two fuel lines going into the tank. Detach all lines from the old tank. The smaller line at the bottom of the tank directs fuel to the engine, while the larger line at the top is used for filling the tank. There may also be a third line, an airline that allows for the decrease in pressure as the fuel travels through the tank.

Now, assess whether you need to drop the rear suspension. If an axle is blocking access to the old tank, you will need to disconnect the shocks and rest the rear suspension beam with a jack. Don't forget to disconnect the brake lines to avoid damaging them and bring the whole assembly down to the floor.

Finally, remove the metal straps and bolts holding the tank in place. This will allow you to lift the tank out and replace it with a new one. Ensure you have taken pictures of the setup before you started, so you know how to reattach the new tank.

Remember, it is important to work in a well-ventilated area when dealing with fuel, and have a fire extinguisher nearby.

Frequently asked questions