Replacing The Fuel Pump On A 99 Buick Lesabre

Replacing the fuel pump on a 1999 Buick LeSabre can be a complex process. The fuel pump is located inside the fuel tank, and accessing it typically requires lowering or removing the tank. Before beginning the replacement, it is essential to have the correct replacement fuel pump for your specific model and all the necessary tools, including a fuel sender lock nut wrench. The process involves disconnecting the black ground battery cable, loosening the fuel filler cap, draining the fuel tank if necessary, relieving the fuel system pressure, raising the vehicle, supporting the fuel tank, detaching the tank straps, lowering the tank to access the fuel pump assembly, disconnecting the hoses and fuel sending unit, and finally removing the old fuel pump. The new fuel pump can then be installed, and the steps are reversed to reassemble the components. It is important to refer to a detailed guide or seek professional assistance when performing this task to ensure a safe and successful fuel pump replacement.

Disconnect the black ground battery cable with a wrench

To disconnect the black ground battery cable with a wrench, follow these steps:

First, locate the black ground battery cable. This cable is connected to the negative terminal of the battery. It is usually identified by a black cover or a "-" symbol.

Once you have located the cable, use a wrench to loosen the nut that secures the cable to the battery terminal. Make sure you have the right size wrench that fits securely on the nut. Turn the wrench in a counter-clockwise direction to loosen it. If the nut is tight, you may need to apply some force to loosen it. Do not strip the nut or damage the cable.

After the nut is loosened, you can now disconnect the cable. Grasp the cable firmly and pull it straight off the terminal. Be careful not to let the cable touch any metal parts of the car, as this could cause a short circuit.

Once the cable is disconnected, place it in a safe location away from the battery and any metal surfaces. You may want to cover the exposed battery terminal with a piece of electrical tape or a terminal cover to prevent accidental contact.

Disconnecting the black ground battery cable is an important step when working on the electrical system of your 1999 Buick LeSabre. It ensures that the power to the fuel pump and other electrical components is cut off, making it safe to proceed with repairs or maintenance.

Loosen the fuel filler cap

To loosen the fuel filler cap on your 1999 Buick LeSabre, you will first need to disconnect the black ground battery cable with a wrench. Once this is done, you can drain the fuel from the tank through the fuel filler tube using a hand siphon pump into an approved container if necessary.

Next, relieve the fuel system pressure by depressing the pressure-test port valve using a small, flat-head screwdriver. You will find the valve located on the fuel rail, in the engine compartment, leading to the fuel injectors. Remember to wrap a shop rag around the valve to catch any fuel that may squirt out.

Now you can begin to raise both wheel assemblies using a floor jack and support the vehicle with jack stands at each side. Support the fuel tank with the floor jack, placing a piece of wood between the tank and the jack saddle to prevent any damage to the tank.

At this point, you can detach the tank supporting straps using a ratchet, ratchet extension, and socket. Lower the fuel tank by about 6 inches to gain access to the hoses connected to the fuel sending unit and pump assembly on top of the fuel tank.

With the above steps completed, you will now have access to the fuel filler cap and can proceed to loosen it.

Drain the fuel from the tank

To drain the fuel from the tank of your 1999 Buick LeSabre, you will need a hand siphon pump and an approved container to put the fuel in. You will also need a small, flat-head screwdriver.

First, disconnect the black ground battery cable with a wrench. Next, loosen the fuel filler cap. Then, drain the fuel from the tank through the fuel filler tube using the hand siphon pump.

Now, you need to relieve the fuel system pressure. To do this, depress the pressure-test port valve using the small, flat-head screwdriver. The valve is located on the fuel rail, in the engine compartment, leading to the fuel injectors. Wrap a shop rag around the valve to catch any squirts of fuel.

Detach the tank supporting straps

To detach the tank supporting straps, you will need a ratchet, ratchet extension, and socket.

First, ensure you have raised both wheel assemblies using a floor jack and supported the vehicle with jack stands at each side. Support the fuel tank with the floor jack, placing a piece of wood between the tank and the jack saddle to prevent any damage to the tank.

Now you can detach the tank supporting straps with the ratchet, ratchet extension, and socket. Once the straps are detached, you will need to lower the fuel tank by about 6 inches to access the hoses connected to the fuel sending unit and pump assembly on top of the fuel tank.

Lower the fuel tank and disconnect the hoses

To lower the fuel tank and disconnect the hoses of your 1999 Buick LeSabre, follow these steps:

First, detach the tank supporting straps using a ratchet, ratchet extension, and socket. Next, carefully lower the fuel tank about 6 inches to gain access to the hoses connected to the fuel sending unit and pump assembly on top of the tank. Place a piece of wood between the tank and the jack saddle to prevent any damage to the tank.

Now, you can begin to disconnect the hoses. On hoses with metal collar fittings, use tool set J-34730. For hoses with plastic collars, depress the retaining tabs and pull the fittings apart. Once all the hoses are disconnected, you can move on to disconnecting the fuel sending unit and pump assembly from the fuel tank using tool number J-39765 or a similar fuel sender lock nut wrench.

It is important to have the necessary tools, such as the special fuel sender lock nut wrench, ready before beginning the process of replacing the fuel pump. Additionally, ensure that you have the correct replacement fuel pump for your specific 1999 Buick LeSabre model.

Frequently asked questions