Replacing The Fuel Pump In Your 84 Bronco Ii

If you're looking to replace the fuel pump on your 1984 Bronco, you'll need to establish whether you have a mechanical or electric fuel pump. If it's a mechanical pump, you'll need to identify whether your Bronco has a six-cylinder or V8 engine, as this will determine the location of the fuel pump.

Once you've located the fuel pump, you'll need to disconnect the electrical connector and all metal and rubber hoses. You'll also need to remove the fuel tank straps and the filler neck. After this, you can start to remove the fuel pump.

If you're replacing an in-tank fuel pump, you'll need to remove the fuel tank and clean the surrounding area to make it easier to work on. You'll also need to disconnect the electrical connector and all metal and rubber hoses going to the fuel pump.

For electric fuel pumps, you'll need to splice the fuel pump wires onto the sender unit and mount the pump using self-tapping screws. You'll also need to connect the ground to one of the mounting screws.

Disconnect the battery and electrical connectors

Disconnecting the battery and electrical connectors is one of the first steps to take when replacing the fuel pump on an 84 Bronco II. Here is a detailed, step-by-step guide on how to do this:

Before beginning any work on your Bronco II, it is important to take the necessary safety precautions. Wear protective gear, such as eye protection, to avoid injury. It is also crucial to work in a well-ventilated area to avoid inhaling fumes. Place the vehicle on a level surface, engage the parking brake, and chock the wheels for added safety.

Now, let's begin with disconnecting the battery and electrical connectors:

• Locate the battery: The battery is typically located in the engine compartment or in the rear of the vehicle.
• Disconnect the negative terminal first: Loosen the nut or bolt securing the negative (black) battery cable using a wrench or socket. Detach the cable from the battery post. You may need to wiggle it gently to remove it completely.
• Disconnect the positive terminal: Repeat the same process for the positive (red) battery cable. Ensure that the cables do not touch any metal parts of the vehicle to avoid creating a short circuit.
• Secure the battery cables: Tie back or cover the battery cables to prevent accidental contact with any metal surfaces.
• Locate the electrical connectors: These are the wires or plugs that supply power to the fuel pump. They are usually located near the fuel pump or along the fuel lines.
• Disconnect the electrical connectors: Using a suitable tool, such as a screwdriver or a fuel line disconnect tool, carefully detach the electrical connectors from the fuel pump. Be gentle to avoid damaging the connectors or surrounding components.
• Cover the connectors: Once disconnected, cover the electrical connectors to protect them from dirt or debris.

By following these steps, you will have successfully disconnected the battery and electrical connectors, allowing you to proceed with the next steps in replacing the fuel pump on your 84 Bronco II. Remember to work carefully and consult a professional mechanic or a detailed repair manual if you have any doubts or concerns during the process.

Remove the fuel tank

To remove the fuel tank from your 1984 Bronco, you will need the following tools:

• A fuel siphon pump or another tool to remove the fuel from the tank.
• A fuel container to store the fuel.
• Two jack stands.
• A jack to safely lower the tank.
• A socket wrench set (sizes 1/4", 6mm, 14mm, 15mm deep socket, 3" extension bar).
• A combination wrench set (to remove the bolts holding the tank shield, probably 13mm).
• A fuel line disconnect tool (a cheapo metal scissor type will do).
• A Phillips-head screwdriver.
• A flat-head screwdriver.
• Siphon the fuel from the tank. It is important to remove the fuel first to avoid handling the extra weight when removing the tank.
• Lift the Bronco using a jack to provide easier access to the fuel tank. A lift of around 3" should be enough.
• Support the fuel tank with a floor jack, ensuring it is centred properly.
• If your Bronco has tank straps, remove them.
• Remove the tank shield. At this point, you should only need to lower the tank slightly, just enough so you don't put any tension on the fuel lines or the pump plug.
• Disconnect the fuel lines and the plug, then remove the tank from under the vehicle.
• Open the tank and retrieve the fuel pump assembly.
• With the tank outside the vehicle, you can now access the pump.

Please note that this guide is a general overview of the process and may not cover all the specific details and variations of your particular model. Always refer to a qualified mechanic or a detailed workshop manual for your vehicle when attempting any repairs or maintenance.

Remove the fuel pump assembly

To remove the fuel pump assembly from your 1984 Bronco, follow these steps:

Firstly, siphon the fuel from the tank. You can use a hand pump for this, but be careful not to spray fuel when detaching the pump. Once the fuel is removed, lift the truck to allow easier access to the fuel tank. You can use a jack to lift the rear of the truck and place jack stands to support the vehicle.

Next, you need to remove the fuel tank shield. This is held in place with eight bolts/nuts. Once these are removed, the tank will be free to move, so ensure it is properly supported. Now, disconnect the fuel lines and the plug from the fuel tank. You will need a fuel line disconnect tool for this. With these disconnected, you can now remove the fuel tank from the vehicle.

With the tank out of the vehicle, open it up and retrieve the fuel pump assembly. To do this, you will need to remove the ring holding the pump assembly in place. This is done by tapping it counter-clockwise with a punch until it releases and turns. Now, with the pump assembly out, you can access the fuel pump itself. To do this, you will need to remove the float by taking out three bolts and disconnecting the red cable. Be careful to note how everything is connected and take pictures if necessary to guide yourself during reassembly.

Finally, to get to the fuel pump, you will need to remove the plastic body cap by undoing the plastic clips all around the body. Be patient with this step and do not use brute force, as you do not want to break any of the tabs or clips. Once the body is open, simply replace the old pump with a new one and reassemble everything following the steps in reverse order.

Replace the fuel pump and pick-up screen

To replace the fuel pump and pick-up screen on your 1984 Bronco, you will need the following tools:

• A fuel siphon pump or another tool to remove the fuel from the tank.
• A container to store the fuel.
• Two jack stands.
• A jack to safely lower the tank.
• A socket wrench set (sizes 1/4", 6mm, 14mm, 15mm deep socket, 3" extension bar).
• A combination wrench set (to remove the nuts/bolts on the tank shield).
• A fuel line disconnect tool.
• A Phillips-head screwdriver.
• A flat-head screwdriver.
• Siphon the fuel from the tank using the fuel siphon pump or an alternative tool. It is important to remove the fuel to avoid spilling and to reduce the weight of the tank.
• Lift the rear of your Bronco using a jack to create some extra space to work with.
• Support the fuel tank with a jack, ensuring it is centred properly.
• If your Bronco has tank straps, remove them.
• Remove the tank shield.
• Lower the tank slightly, taking care not to put tension on the fuel lines or the pump plug.
• Disconnect the fuel lines and the plug from the fuel tank.
• Remove the tank from under the vehicle.
• Open the tank and retrieve the fuel pump assembly.
• Replace the old fuel pump and pick-up screen with the new ones.
• Reinstall the fuel tank and connect the fuel lines and plug.
• Lift the tank and shield back into place and reinstall the tank straps, if applicable.
• Refill the tank with fresh fuel and test your Bronco to ensure it is working properly.

Note: It is recommended to wear eye protection and disconnect the battery before starting this procedure. Additionally, some steps may vary depending on the specific model and configuration of your Bronco.

Reinstall the fuel tank

To reinstall the fuel tank of your 1984 Bronco, follow these steps:

• Slide the locking ring back into place. Tap it gently with a screwdriver and hammer/mallet, or use a brass punch to avoid making sparks.
• Reattach the float and sock to the fuel pump, being careful not to drop the sock into the tank.
• Reconnect the wires to the fuel pump and secure them with bolts.
• Reattach the fuel pump to the sender unit, using the provided nuts.
• Reinsert the O-ring.
• Reattach the skid plate to the bottom of the fuel tank, using bolts.
• Reattach the filler neck to the fuel tank.
• Slide the fuel tank back into place under the vehicle.
• Reconnect the electrical connector and all metal/rubber hoses to the fuel pump.
• Reattach the fuel tank straps, if applicable.
• Lower the vehicle.

Note: It is recommended to clean the area before reinstalling the fuel tank to prevent dirt and debris from falling into the tank. Additionally, it is suggested to replace the O-ring and crimp the splice connections instead of soldering them.

Frequently asked questions