Replacing The Fuel Pump In Your 99 Cadillac: Step-By-Step Guide

If you're experiencing issues with your 99 Cadillac's fuel pump, it may be time to consider replacing it. The fuel pump is responsible for delivering fuel from the tank to the fuel injectors, and a failing pump can cause a range of issues, from strange engine noises to complete engine failure. While it is possible to replace the fuel pump yourself, it is a complex and risky job, so it is recommended to seek the help of a professional mechanic. The average cost for a fuel pump replacement is between $611 and $894, but this can vary depending on your vehicle's specific make and model.

Disconnect the battery

Disconnecting the battery is the first step when replacing the fuel pump in a 99 Cadillac. This is important to reduce the chance of a fire.

First, locate the battery. It is usually found in the engine bay, on the side of the vehicle, or in the trunk. Once you have located the battery, gather the necessary tools, which typically include a wrench or socket set to loosen the battery cables and a pair of safety gloves and goggles to protect your hands and eyes.

Next, identify the positive and negative battery terminals. The positive terminal will be marked with a "+" sign, and the negative terminal will be marked with a "-" sign. Loosen the nut on the negative terminal using your wrench or socket. Be careful not to let the wrench touch any metal parts of the car, as this could cause a short circuit. Once the nut is loose, carefully remove the cable from the terminal. You may need to wiggle it gently to detach it. Set the cable aside, ensuring it does not touch any metal parts of the car.

Now, repeat the process for the positive terminal. Again, be cautious to avoid any contact between the wrench and the car's metal components. With both cables disconnected, you can now safely remove the battery. Place it in a secure location, making sure it is away from any flammable materials.

It is important to note that some modern vehicles may have additional steps or procedures for disconnecting the battery. These may include disabling certain systems or following specific sequences for disconnecting the terminals. Always refer to the vehicle's repair manual or seek advice from a qualified mechanic if you are unsure about the process.

Additionally, when working on any part of a vehicle's fuel system, it is crucial to take all necessary precautions to prevent fires. Have a fire extinguisher nearby and avoid any actions that could create sparks or ignition sources.

Remove the fuel tank

To remove the fuel tank from a 1999 Cadillac, follow these steps:

Firstly, relieve the fuel system pressure and remove the filler cap. Drain the fuel tank. It is important to note that gasoline or gasoline vapors are highly flammable, so take the necessary precautions. Have a dry chemical (Class B) fire extinguisher nearby.

Next, raise and support the vehicle. Remove the right rear wheelhouse extension to gain access to the rear frame support bolts under the rear fascia. Remove the rear frame support.

Disconnect the fuel feed line at the fuel filter and the return line near the fuel filter. Remove clamps from the fuel tank breather hose and EVAP hoses at the fuel tank near the fuel filter, then disconnect the hoses. Remove the fuel sender electrical connector retainer and disconnect the connector.

With the aid of an assistant, support the fuel tank and remove the following bolts:

• Left fuel tank retaining strap attaching bolts (2)
• Right fuel tank strap attaching bolts (1)
• Both fuel tank retaining straps

Lower the tank and place it in a suitable work area.

If you are replacing the fuel tank, you will need to remove the fuel sender assembly, exhaust heat shield, ground strap, and fuel pressure sensor. Reinstall these components into the new tank.

Now, raise the new fuel tank with the aid of an assistant. Install the fuel tank retaining straps, left attaching bolts, and right attaching bolts. Tighten the fuel tank retaining strap bolts to 34 N·m (25 lb ft).

Connect the fuel sender electrical connector and reinstall the retainer. Connect the fuel tank breather hose and the EVAP hoses to the fuel tank and install new clamps.

Finally, install the fuel feed and return line quick-connect fittings. Install the fuel filter and fuel tank ground strap to the retaining bracket and tighten to 22 N·m (16 lb ft).

Please note that it is important to use the correct fasteners in the correct locations and to follow the correct tightening sequence and specifications when installing fasteners.

Disconnect the electrical connectors

Before disconnecting the electrical connectors, it is important to relieve the fuel system pressure and drain the fuel tank. This is because gasoline or gasoline vapors are highly flammable, and a fire could occur if an ignition source is present.

Now, to disconnect the electrical connectors, you will need to remove the fuel tank. If your 1999 Cadillac has an access hatch in the trunk, you can do this by removing the spare tire and compartment carpet liner. The access hatch is towards the rear on the passenger side. If there is no access hatch, you will need to drop the tank.

Once you have access to the fuel tank, disconnect the electrical connectors from the fuel tank pressure sensor and the fuel tank connection cover. Remove the fuel pressure and return lines from the tank connection cover and discard the clamps. Remove the air reference hose from the fuel tank pressure sensor.

It is important to note that you should not remove the steel band around the fuel sender lock nut. This does not need to be removed in order to loosen the fuel sender lock nut.

Remove the fuel pressure and return lines

To remove the fuel pressure and return lines of a 1999 Cadillac Catera, follow these steps:

Firstly, relieve the fuel system pressure and remove the filler cap. Then, drain the fuel tank.

Next, disconnect the fuel feed line at the fuel filter and the return line near the fuel filter. Remove the clamps from the fuel tank breather hose and EVAP hoses at the fuel tank near the fuel filter, and then disconnect the fuel tank breather hose and the EVAP hoses.

Now, remove the fastener securing the fuel tank pressure sensor to the fuel tank connection cover and remove the sensor. Then, remove the fuel pressure and return lines from the tank connection cover and discard the clamps.

Finally, you can remove the fuel pump electrical connectors.

Install the new fuel pump

To install the new fuel pump, follow these steps:

Firstly, ensure the fuel pump is installed inside the housing, with the suction pipe seated in the recess at the bottom of the housing. Then, install the locking ring and snap the locking tabs into the housing.

Next, install a new fuel inlet screen onto the fuel pump, ensuring it is in the same position as noted when removing the old pump. Then, install the fuel pump assembly into the tank and lock down the tabs.

Connect the fuel line to the fuel pump using a new clamp. Then, connect the fuel pump electrical connectors.

If you are servicing the fuel sender assembly, always replace the fuel sender assembly lip seal. Install a new lip seal on the tank as follows: pull the seal over the fuel tank connection cover, slide the seal over the wires and hoses to the fuel tank opening, and fit the groove in the side of the seal into the lip in the fuel tank opening.

Finally, install the fuel tank connection cover on the fuel tank opening, tightening the locking nut to 50 N·m (37 lb ft). Be sure that the lip seal provides a snug seal between the fuel sending unit and the fuel tank.

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