A fuel pump is used to feed gas from the fuel tank of the Cadillac Deville to the engine. When the fuel pump begins to go bad, the Deville's performance will suffer and eventually the vehicle won't run at all. The fuel pump is located inside the vehicle's gas tank. Two people are needed to handle the gas tank removal and extreme caution should be exercised because of the combustible nature of the fuel.
Park the Deville on a level surface and set the parking brake. Open the hood and disconnect the negative battery cable.
Place the jack under the rear of the car, in the center of the frame. Lift the Deville until jack stands can be placed under the rear axles.
Open the gas cap and siphon as much gas as possible into a spare gas can.
Unplug the wiring harness attached to the rear of the fuel tank.
Loosen the hose clamps on the fuel filler line with a flat head screwdriver. Remove the hose. Do the same with the fuel vent hose.
Position the jack at the exact center of the fuel tank and lift it until it touches the tank. Unbolt the tank straps with a socket wrench and let the weight of the tank settle on the jack. Have one person keep the tank steady while the straps are being removed.
Lower the jack until the fuel lines can be removed from the top of the fuel tank. Loosen the hose clamps with a flat head screwdriver, then pull the hoses free. Lower the jack the rest of the way and remove the fuel tank from under the car.
Undo the fuel pump lock ring by twisting it counterclockwise until it comes free. Remove the fuel pump from the tank.
Place the new fuel pump in the tank and twist the fuel pump lock ring clockwise to tighten it. Put the fuel tank back under the vehicle.
Connect the fuel lines to the top of the tank and secure them in place by tightening the hose clamps with a screwdriver. Lift the fuel tank slowly with the jack until it is in place, then secure the straps to the tank with a socket wrench.
Reattach the fuel filler line and fuel vent line, then tighten their hose clamps with a flat head screwdriver. Plug the wiring harness back in to the rear of the tank. Move the jack to the rear of the car, lift it a few inches, remove the jack stands then lower the vehicle. Replace the negative battery cable and gas cap.
