Replacing The Fuel Pump In A Classic '55 Chevy Truck

Changing the fuel pump on a 1955 Chevy Truck can be a challenging task, but with the right tools and precautions, it is certainly doable. Before beginning, ensure you have the necessary tools, such as a ratchet with an extension and a 15 mm socket, wire snips and strippers, a heat gun for wiring shrink wrap, and shop rags to handle any spilled fuel. It is crucial to work in a well-ventilated area, free from heat sources, sparks, and open flames, and to avoid smoking while working.

The first step is to relieve the fuel line pressure by pulling the fuel pump relay from the fuse box and letting the engine run until it shuts down. Next, use a jack to lift the truck and place it on jack stands, or lift the entire truck if you don't have access to a jack. Then, remove the fuel filler neck from the tank, which can be tricky due to its location. Disconnect the fuel tank lines, including the vapor line and the larger supply line, followed by the two lines above them with white connector clips. Be prepared for spilled gasoline during this step.

Disconnect the power lines to the fuel pump, and then remove the gas tank straps and lower the tank carefully, preferably with assistance. Clean around the fuel pump, disconnect the lines, and remove the locking ring to take out the pump module. Assemble the new fuel pump, attach the float, and seal it. Install the new pump, secure it with the locking ring, and reconnect the lines and power plugs. Reinstall the gas tank and test your work by starting the truck.

Removing the old fuel pump

To remove the old fuel pump from your 1955 Chevy Truck, you will need to perform the following steps:

Firstly, relieve the fuel line pressure by pulling the fuel pump relay from the fuse box and starting the vehicle until it runs out of fuel and shuts down. This will ensure that there is no residual pressure in the lines when you begin working. Ensure you are working in a well-ventilated area, free from any heat sources, sparks, or open flames, and do not smoke while working with fuel sources.

Next, you will need to lift the truck using a jack and place it on jack stands in the manufacturer's recommended locations. If you don't have access to a lift, it is recommended to lift the entire truck rather than just the rear end.

Now, locate the fuel filler neck on the driver's side of the tank, above the frame. Use a stubby flat-head screwdriver to loosen the hose clamp and remove the fuel filler neck. Then, move to the passenger side of the tank and disconnect all the lines going into the top of the tank, including the vapor line and the larger supply line. Be prepared for some fuel spillage when removing these lines. Wear safety goggles to prevent gasoline from getting into your eyes.

At this point, disconnect the two quick-release electrical plugs on top of the fuel tank that power the fuel pump. Then, use a ratchet with a long extension to remove the gas tank straps. For the rear strap, you may need an assistant to hold the tank while you remove it, as it will be heavy. Alternatively, you can use a hydraulic floor jack to support the tank during this process.

With the tank straps removed, you can now carefully lower the tank. Clean around the fuel pump to remove any debris, leaves, or rust. Then, disconnect the three lines from the fuel pump by squeezing the quick-release clips and pulling the hoses off. Turn the locking ring counter-clockwise to release it, and then remove the entire fuel pump module. Be cautious, as more fuel will drain from the tank during this step.

Now that the old fuel pump has been removed, you can proceed to install the new fuel pump module.

Installing the new fuel pump

Now that you've relieved the fuel line pressure, lifted the truck, disconnected the fuel tank lines, power lines, and removed the gas tank straps, you can begin installing your new fuel pump.

First, clean around the fuel pump to remove any debris, leaves, or rust. You don't want any of that falling into the tank. Next, disconnect the three lines from the fuel pump. Squeeze the clips with one hand and pull the hose off with the other. Once the hoses are off, turn the locking ring counter-clockwise and it should pop right up. Then, carefully fish it off the top of the tank. Pull up on the pump and remove the entire module.

Your new fuel pump may need minor assembly. It likely didn't come with the float attached to the fuel level gauge, but this simply snaps into place. Look at your old pump for guidance. It also may not have come with the seal in place, so again, refer to the old pump to see how this is attached. Then, slide the fuel pump seal up to the top of the module. It may be easier to put the seal on before you put on the float arm. Compare the electrical wiring harness on the new module with the old one. They may be different, in which case you'll need to rewire with the new harness.

Now, install the new fuel pump onto the tank and secure it with the locking ring. Using a light spray lubricant on the seal will make it easier to put back into the tank. There is a tab on the pump that marries to the top of the tank, so it can only go in one way. Replace the locking ring and turn it clockwise until it clicks back into position.

Pull the quick-release tabs off the old fuel lines and put them onto the nipples of the new fuel pump. Reconnect the three fuel lines to the quick-connect tabs. If you have to swap out the wiring harness, make sure you do not cut into the wires for the fuel pressure sensor. That harness always gets reused and should not be replaced. The supplied harness should have wire colors that match the existing wires. If not, carefully follow the supplied instructions for re-wiring. The existing wires should include two thicker and two thinner wires. Be sure to splice the thick black wires together with the new thick black wires and the thin wires with the thin wires.

Since getting to the fuel pump is a big job, consider soldering these wires together to ensure they don't go bad. Solder them and use shrink wrap over the spliced area. Tuck all the cabling back into the plastic sheathing.

Fuel pump maintenance tips

A fuel pump is an integral part of a car. It draws fuel out of the tank through a pipe to the carburetor, where it mixes with air. The engine then sucks in this mixture of air and fuel. Given the crucial role of the fuel pump in making your car move, it's important to perform regular maintenance to avoid potential issues. Here are some tips to help keep your fuel pump in good condition:

Keep Your Gas Tank at Least a Quarter Full

Topping up your gas tank regularly is important for fuel pump health. Gasoline acts as a coolant for in-tank fuel pumps, so driving with a low fuel level causes the pump to overheat and work harder, reducing its lifespan.

Use Branded Fuel

Using branded fuel can improve pump performance and help extend its life.

Avoid Letting Your Pump Run Dry

If you're not going to be using your pump for more than a week, use an anti-ethanol agent to prevent the fuel from solidifying or turning into a gel.

Perform Regular Fuel System Maintenance

Regularly inspect and replace your fuel system and fuel filters when necessary. This proactive approach can help you avoid unexpected issues.

Perform Visual and Functional Inspections

Conduct both visual and functional inspections of your fuel pump. During a visual inspection, check the seals for leaks and ensure all connectors are secure. For a functional inspection, use a pressure rig to verify that the pump is regulating pressure correctly.

Keep the Fuel Control Unit Moisture-Free

When performing a compressor wash, take care to prevent moisture from entering the fuel control unit. Water contamination can lead to galvanic corrosion, damaging the unit and impairing the fuel system's performance.

Uncouple the Gas Line

When changing the fuel pump, it's a good idea to uncouple the gas line behind the seat to prevent the gas from siphoning when you detach it from the pump. Also, loosen the gas cap to relieve any pressure in the tank.

Safety precautions when changing the fuel pump

Changing a fuel pump can be a challenging and dangerous task, so it's important to take the proper safety precautions. Here are some detailed safety instructions to follow when changing the fuel pump of a 1955 Chevy Truck:

Prepare the Workspace

Before starting the repair, ensure your workspace is safe and accessible. Work in a well-ventilated area, preferably outdoors, to minimize the risk of fire and inhaling toxic fumes. Keep the workspace clean and free of debris to prevent anything from falling into the fuel tank.

Prepare Your Person

Always wear safety gear, including safety glasses and gloves, to protect yourself from fuel spills and splashes. Wear appropriate clothing that covers your arms and legs to minimize skin exposure to fuel.

Prepare the Vehicle

Reduce the amount of fuel in the tank to minimize the risk of spillage and make the tank lighter and easier to handle. Disconnect the battery and pull the fuel pump relay to deactivate the fuel pump. If possible, drain or siphon out most of the fuel from the tank. Consult the 1955 Chevy Truck service manual or online tutorials for additional vehicle-specific guidance.

During the Repair

Be cautious when removing the old fuel pump to avoid spilling fuel. Take note of the fuel line connections and wiring before removing the pump. When reassembling the fuel system, ensure all connections are secure and test the new fuel pump to ensure proper functioning.

Additional Tips

Consider replacing related components such as the fuel filter, fuel pump strainer, and fuel tank O-ring or gasket when changing the fuel pump. Always use fuel-safe equipment and never smoke or use matches, lighters, or any other ignition sources near the vehicle.

Tools required for the job

To change the fuel pump on a 1955 Chevy Truck, you will need a range of tools to ensure the job is done safely and effectively.

Firstly, you will need a ratchet with an extension and a 15 mm socket. This will be used for removing the gas tank straps and lowering the tank. A stubby flat-head screwdriver will also be useful for loosening the hose clamp and removing the fuel filler neck. You will also need wire snips and a wire stripper for any wiring adjustments. A heat gun will be required for wiring shrink wrap, and it is important to have plenty of shop rags available to deal with any spilled fuel.

Safety is paramount when working with fuel, so ensure you have safety goggles to protect your eyes from any gasoline splashes. It is also crucial to work in a well-ventilated area, away from any heat sources, sparks, or open flames.

For lifting the truck, you will need to use appropriate lifting points and place the vehicle on jack stands in the manufacturer's recommended locations on level ground. If you don't have access to a lift, you may need to lift the entire truck rather than just the rear end, so ensure you have enough jack stands.

Additionally, a long bolt may be useful for holding the fuel pump pushrod in place during the removal and installation process. Grease, such as white lithium lubriplate grease, can also be applied to the fuel pump arm to keep it lubricated.

Finally, a light spray lubricant can be used on the new fuel pump seal to make it easier to insert back into the tank.

Frequently asked questions