Replacing The Fuel Pump In A 1999 Jeep Cherokee

Changing the fuel pump on your 1999 Jeep Cherokee can be a dangerous and challenging task, but it is doable with the right tools and precautions. The fuel pump is located in the fuel tank, and the process involves disconnecting and reconnecting various parts, including hoses, electrical connections, and mounting brackets. It is crucial to relieve the fuel system pressure and ensure there is less than a half tank of fuel before beginning the replacement process. This job requires careful handling of flammable and toxic substances and should only be attempted with the necessary expertise and safety measures in place.

Disconnect the negative battery cable

Before beginning any work on your vehicle's fuel system, it is crucial to ensure your safety and the safety of those around you. Work in a well-ventilated area, away from any open flames or sparks, and avoid smoking or bringing any ignition sources close to the vehicle.

Now, to begin the process of changing the fuel pump in your 1999 Jeep Cherokee, one of the first steps is to disconnect the negative battery cable. This is a standard procedure when working on any vehicle's electrical system, as it helps prevent short circuits and other electrical issues. Here's a detailed guide on how to do it:

Locate the negative battery terminal: Open the hood of your 1999 Jeep Cherokee and identify the battery. The negative terminal is usually indicated by a "-" sign or a black cover. It is often on the left side of the battery, but this may vary depending on your vehicle's configuration.

Prepare your tools: Before disconnecting the battery cable, make sure you have the necessary tools ready. You will need a suitable socket or wrench that fits the battery terminal clamp. A combination of a 10mm socket and a ratchet is commonly used for this purpose. Have a safe and suitable place to keep the disconnected cable as well, such as a clean and dry surface away from any metal objects.

Loosen and remove the negative cable: Once you have located the negative terminal and prepared your tools, it's time to disconnect the cable. Place the wrench or socket on the terminal clamp and loosen it by turning it in a counter-clockwise direction. Be gentle and careful to avoid any sparks. Once it is loose, lift the cable straight up and away from the battery terminal. Do not let the cable touch any metal parts of the vehicle to prevent any accidental short circuits.

Secure the cable: After disconnecting the negative cable, make sure to secure it properly. Place it in a safe location away from the battery and any metal objects that could cause a short circuit. Ensure that the cable cannot accidentally fall back onto the battery terminal or touch any metal parts during the fuel pump replacement process.

Verify the disconnection: Before proceeding with the fuel pump replacement, verify that the negative battery cable is indeed disconnected. Check that there is a secure distance between the cable and the battery terminal, and ensure that the cable is not resting on or touching any metal parts of the vehicle. This step is crucial to ensure your safety and prevent any unexpected electrical issues.

By following these detailed steps, you can safely and effectively disconnect the negative battery cable in your 1999 Jeep Cherokee, allowing you to proceed with the fuel pump replacement process. Remember to exercise caution and follow established safety procedures when working on your vehicle's electrical and fuel systems.

Relieve the fuel system pressure

To relieve the fuel system pressure on a 1999 Jeep Cherokee, follow these steps:

Firstly, locate the test port. Place some towels around the port and use a small screwdriver to press against the port, relieving the pressure. If your Jeep does not have a test port, place towels around the end of the fuel rail and disconnect the fuel line from the rail. This will also relieve the pressure in the system.

Next, disconnect the negative battery cable with a wrench. Ensure you take great care when working with any fuel system, as the fuel is extremely toxic and flammable.

Now, drain your fuel tank as much as possible. Siphoning with a hose is not recommended due to safety hazards, so instead, use a siphon pump and a gas can. You need to get the gas level well below the fuel pump portal in the tank.

At this point, you can remove the fuel pump. To do so, carefully slide under the vehicle, ensuring it is securely supported and raised if necessary. You can then begin to remove the hoses and electrical connections to the pump. Loosen the hose clamp at the filter inlet and return line with a flat-blade screwdriver, and then remove the lines. Be sure to also disconnect the electrical leads from the pump.

Finally, remove the lock ring by turning it counter-clockwise with a brass drift and a hammer. Once the lock ring is off, carefully remove the pump assembly from the tank.

Disconnect hoses and electrical connections

Disconnecting the hoses and electrical connections is a crucial step in changing the fuel pump of a 1999 Jeep Cherokee. Here is a detailed guide on how to do this safely and effectively:

First and foremost, safety should be a priority. Ensure that you are working in a well-ventilated area and that there are no sources of ignition nearby, such as naked flames or sparks. It is also recommended to keep metal-on-metal contact to a minimum to reduce the risk of sparks.

To begin, locate the fuel pump and the associated hoses and electrical connections. Place towels around the work area to absorb any spilled fuel. Using a flat blade screwdriver, carefully loosen the hose clamps at the filter inlet and return line. These are located just in front of the fuel tank, above the tank lock ring. Once loosened, remove the hoses.

Next, disconnect the electrical connections to the fuel pump. Cut any zip ties securing the wires to the rail and carefully unplug the fuel pump connector from the main harness. The connector is typically located next to the filter and passenger-side frame rail above the axle tube.

Now, focus on the fuel pump itself. Using a brass drift and hammer, loosen the lock ring by turning it counter-clockwise. Be cautious, as the fuel tank should only be half full or less before removing the lock ring. Once the lock ring is removed, carefully take out the pump assembly from the tank.

With the pump assembly removed, you can now access the electrical leads connected to the pump. Use a jeweler's flat-blade screwdriver to loosen the spade terminals and carefully detach the electrical leads. Be mindful of the pump's orientation to avoid damaging any components.

At this point, you have successfully disconnected the hoses and electrical connections associated with the fuel pump. You can now proceed with the next steps of changing the fuel pump, such as removing the pump strainer and output hose, and installing the new pump assembly. Remember to work carefully and refer to a repair manual or seek professional assistance if you encounter any difficulties.

Please note that this guide provides general instructions, and it is recommended to consult a qualified mechanic or a Jeep Cherokee repair manual for specific details pertaining to your vehicle's make, model, and year.

Remove the old fuel pump

To remove the old fuel pump from your 1999 Jeep Cherokee, follow these steps:

Firstly, safety is paramount when working with fuel systems. Ensure the engine is off and disconnect the negative battery cable with a wrench. This will prevent any accidental sparks during the removal process.

Next, locate the fuel tank and ensure it is less than half full. If it is more than half full, you will need to drain the fuel tank as much as possible. Siphoning with a hose is one method, but for safety, use a siphon pump and a gas can. The fuel level needs to be well below the fuel pump portal in the tank.

Now, crawl under the vehicle and locate the fuel pump. You will need to unplug the fuel pump connector from the main harness. There may be zip ties securing the wire to the rail, so cut these ties to remove the wire. The connector should be hanging next to the filter and passenger-side frame rail above the axle tube.

Using a flat-blade screwdriver, loosen the hose clamp at the filter inlet and the return line. These are located just in front of the tank, above the tank lock ring. With the hoses loosened, you can now focus on removing the lock ring. Using a brass drift and hammer, loosen the lock ring by turning it counter-clockwise. Be careful not to damage the surrounding components.

Once the lock ring is removed, carefully take out the pump assembly from the tank. Be mindful of the fuel gauge sending unit and any wires or hoses connected to the pump. You may need to use a jeweler's flat-blade screwdriver to loosen the spade terminals on the pump.

Finally, disconnect any electrical leads or wires from the old fuel pump. Pay attention to the terminals and ensure they are not shorted during this process. With all connections removed, the old fuel pump can now be fully extracted from the vehicle.

This process requires careful attention to safety and detail. Take your time and ensure you are comfortable with each step before proceeding.

Install the new fuel pump

To install the new fuel pump, first, install the new rubber isolators onto the new pump, both top and bottom. Slide the pump onto the lower mounting bracket, ensuring the lower isolator is centred. Then, slide the pump's upper bracket onto the pump, keeping the terminals on the flat side of the upper mounting.

Next, tighten the nut securely, keeping the pump centred. Install the pump strainer by pushing it firmly into place. It's indexed, so it can only go on one way, with the strainer parallel to the sender float and arm. Connect the fuel pump output hose to the pump and tighten the clamp. You may need to use a new output hose, which should come with the new pump.

Now, install the spade terminal to post terminal adapters using the supplied brass nuts and washers. The smaller spade goes on the negative terminal, which is labelled on the pump. Reconnect the electrical leads. These are indexed by size, so as long as the spades are on the correct terminals, you're okay.

Finally, install the pump/sender into the tank, using the new O-ring seal between the tank and pump. You may be able to reuse the old O-ring. Reinstall the lock ring using a brass drifter/hammer and turning it clockwise until the tabs on the ring touch the tabs on the tank.

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