Replacing Fuel Pump In '68 Mustang: Step-By-Step Guide

Replacing the fuel pump in a 1968 Ford Mustang is a fairly simple task that can be completed in about half an hour. The fuel pump is located under the cam in the engine block and works on a vacuum principle to draw fuel from the tank to the carburettor. The pump is held in place by two bolts, which need to be removed in order to take out the old pump and install the new one. When reinstalling the new fuel pump, it is important to clean the engine block surface and apply a gasket sealer to ensure a tight seal. Additionally, the fuel lines and fuel filter should be inspected and replaced if necessary.

Disconnect the battery and clamp the fuel line

Disconnecting the battery and clamping the fuel line are crucial steps when replacing the fuel pump of a 1968 Ford Mustang. Here is a detailed guide to help you through the process:

Disconnect the Battery

First, locate the positive battery cable connected to the Mustang's battery. This is usually a thick red cable attached to the positive terminal (+) of the battery, which can be identified by its red cap or cover. Once located, use an appropriate tool such as a wrench or pliers to loosen the nut or bolt securing the cable. Be sure to wear protective gloves and eyewear during this process. With the nut or bolt loosened, carefully disconnect the cable from the battery terminal. If your Mustang has a clamp-type battery terminal, you may need to use a screwdriver to loosen the clamp before removing the cable.

Clamp the Fuel Line

The next step is to stop the flow of fuel from the fuel tank to the engine. Place a container or absorbent material under the fuel pump area to catch any spills or leaks. Identify the incoming rubber fuel line, which is usually a flexible hose connected to the fuel pump. Clamp this line with locking pliers or vise grips to stop the flow of fuel. If your Mustang still has the original spring-type clamp, use a screwdriver or pliers to remove it. With the clamp removed, gently pull on the hose to slide it off the fuel line. Inspect the hose for any cracks, wear, or signs of aging, and replace it if necessary.

By following these steps, you will have successfully disconnected the battery and clamped the fuel line, ready to proceed with the fuel pump replacement. Remember to work in a well-ventilated area and take all necessary safety precautions when working with fuel and electrical systems.

Remove the old fuel pump

To remove the old fuel pump from your 1968 Ford Mustang, you will need a replacement fuel pump, a fuel filter (optional but recommended), a gasket sealer, a sharp scraper, degreaser, sockets, a fuel cut-off clamp, a fuel line, clips, rags, and a drip tray.

The first step is to clamp the fuel flow from the fuel tank to prevent leaks. You can do this by clamping the fuel pipe with a simple screw-up clamp to squeeze the rubber pipe. Place a drip tray underneath to catch any fuel that may leak out.

Next, disconnect the connection to the fuel pump. Depending on your setup, you may need to remove crushed (lemon) style clips or a simple jubilee clip. If you are unable to undo the jubilee clip without dripping fuel, you may need to cut the rubber pipe to start the removal. Once the pipe is disconnected, there may be remnants of fuel that will run out.

Now, remove the output side of the fuel pump. This is a metal pipe that goes up to the carburettor and is held in place by a nut. Unscrew this nut and be prepared for any remaining fuel to run out.

The fuel pump body is held in by two bolts. Remove these bolts and take out the fuel pump from the engine block. Be careful not to let anything fall into the engine block, and take care with broken gasket debris. The fuel pump may have part of the gasket still stuck to it, so use a sharp scraper to remove any remaining gasket material from the mounting flange on the engine. Wipe down the area to ensure a clean, smooth surface for the new gasket to adhere to.

With the old pump removed, you are now ready to install the new fuel pump.

Clean the engine block surface

To clean the engine block surface, you will need to remove the remnants of the old gasket from the engine block. This can be done with a sharp scraper or razor blade. It is important to work away from the opening, always scraping from the centre outwards.

Once you have removed the old gasket, you should wipe down the engine block surface with a degreaser on a lint-free cloth to ensure that it is grease-free and ready for the new gasket to be applied.

When cleaning the engine block, it is important to be careful not to drop anything inside and to dispose of the old gasket and any debris safely.

Apply a gasket sealer

Once you have removed the old gasket, it is important to prepare the surface for the new gasket to ensure a proper seal. Clean the gasket mating surfaces on the fuel pump and the mounting surface on the block with a gasket remover or a similar product. This will remove any remaining gasket material, dirt, or grease, and provide a clean base for the new gasket. Use a wire brush or a scuff pad to roughen up the surfaces slightly, creating a better base for adhesion. This step is crucial, as any remaining debris or old gasket material can compromise the seal and lead to fuel leaks.

After the surfaces are clean and prepared, it's time to apply the gasket sealer. Choose a high-quality gasket sealer that is compatible with fuel and the materials of your fuel pump and engine block. Silicone-based gasket sealers are a common choice, but always refer to the manufacturer's recommendations. Apply the gasket sealer to both the fuel pump gasket mating surface and the mounting surface on the block. Follow the instructions on the sealer for the proper amount and technique. Typically, you will apply a thin, even coat to both surfaces, ensuring that the entire surface is covered.

It is important to work quickly once the gasket sealer is applied. Refer to the sealer's instructions for the recommended assembly time. Place the new gasket into position on the fuel pump, ensuring it is correctly aligned with the mounting surface on the block. Carefully lower the fuel pump into place, ensuring that the gasket does not shift or become misaligned. Tighten the fuel pump bolts securely, following the recommended torque specifications and sequence for your Mustang's fuel pump. Any excess gasket sealer that squeezes out should be wiped away promptly with a clean rag.

Allow the gasket sealer to cure for the recommended time before starting the engine. This curing time ensures that the sealer has fully bonded and set, providing an effective seal. Refer to the sealer manufacturer's instructions for the specific curing time. Once the curing time has passed, you can start the engine and check for any fuel leaks. If there are no leaks, you have successfully installed the fuel pump and applied the gasket sealer. If leaks are present, recheck your work and ensure that the gasket is properly seated and tightened correctly.

Reattach the fuel line and check for leaks

Now that you've replaced the fuel pump, it's time to reattach the fuel line and check for leaks.

First, you'll want to attach the metal carb pipe to the output (female side) of the new pump. Tighten the pipe into the mounting. Depending on the design of your pump, you may need to hold the mounting point nut with another spanner to avoid breaking the spot weld on the pump. If you have a concourse pump replacement, you won't need to do this as the casting is all in one.

Next, you'll attach the input line of the fuel pipe to the male part of the fuel filter. Make sure to use the correct tool for a neat finish. There will be a flow arrow for the direction of the fuel on the filter, so ensure the arrow is pointing towards the fuel pump. You can use a single ear clip or a jubilee clip to attach the pipework.

Make sure the rubber fuel pipe is not kinked and forms as straight a route as possible to the fuel pump. Place the tubing to the fuel pump (male fitting) and secure it in place with a clip or jubilee clip.

Now, you can fill the filter with some fuel so it's primed and ready. Alternatively, you can start with the filter empty, so any fuel you see in the filter has been pulled in by the pump itself when cranking over without starting the engine.

When connecting back to the fuel line coming from the inner fender, undo the clamp previously put in place to stop fuel seeping, and slip the new rubber pipe back over the fuel line.

Finally, check that all bolts and clips are secure. You don't want a fuel leak or oil leaking from the back of the pump. Crank the engine to make sure all is correct before trying to start the car fully.

And that's it! You've successfully replaced the fuel pump on your 1968 Ford Mustang and can now enjoy better starting, smoother running, and a steadier idle.

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