In any 1993 Cadillac you will have to take off the fuel tank to change the fuel pump. Taking off the fuel tank is a much easier job if it is empty, but this is usually not the case when the fuel pump goes out. You can siphon the fuel out with a hose before you take the fuel tank down; this will save you a lot of trouble when lowering the tank and moving away from the vehicle.
Remove the negative battery cable. Jack the rear of the car up with the floor and place jack stands under the chassis on either side of the vehicle. Let the car down on the jack stands. Slide under the car and go directly behind the fuel tank. Find and disconnect the electrical connector to the fuel pump.
Start the vehicle and let it run until it stops on its own, this should be only a few seconds if it starts at all. Starting the car in this manner, with the fuel pump not working, will use up all the fuel in the line and relieve any pressure.
Loosen the hose clamp that holds the fuel filler hose to the fuel tank. Roll the jack stand under the car and directly under the fuel tank. Raise the jack until it is touching the bottom of the tank. Use the socket set and ratchet to remove the two metal straps that hold the tank in place. Lower the tank just enough to get your hand to the top.
Reach on top of the tank and unhook the fuel intake line, the return line and the vent-to-canister lines. Lower the fuel tank down to the ground and pull it from under the car.
Place the flat head screwdriver on the tab that is attached to the locking ring on the round hatch on the fuel tank. Tap the screwdriver so that the locking ring will turn counterclockwise. Remove the locking ring and the hatch cover.
Pull the old fuel pump out of its cradle that is attached to the bottom of the hatch cover. Replace it with the new fuel pump and replace the hatch cover. Place the locking ring over the cover and gently tap it clockwise until it is seated securely.
Jack the tank back into position under the car. Leave enough room to be able to put the 3 fuel lines back on. Replace the fuel lines and jack the fuel tank all the way up into place. Reattach the two metal straps that hold the tank in place. Tighten the bolts until the straps are secure. Reconnect the electrical connector and gently pull on it to make sure it is connected properly.
Put the floor jack on a strong part of the chassis and jack the car up and off of the jack stands. Remove the jack stands and lower the car onto the ground. Replace the battery cable and start the vehicle. Let the vehicle run fro a couple of minutes to make sure the pump is working correctly.
