The 1996 Buick Park Avenue was available in two different models: the base model Park Avenue, and the Park Avenue Ultra. Both of these vehicles were equipped with a 3.8-liter V6 engine, capable of producing up to 205 horsepower and 230 foot-pounds of torque. The 1996 Park Avenue was produced with multi-port electronic fuel injection. The fuel pump on the 1996 Park Avenue was an electromechanical pump, and the fuel delivery system was electrical as well. Replacing the fuel pump on the 1996 Park Avenue is a challenging and high risk project. Read the attached Material Safety Data Sheet and information with regards to dealing with automotive gasoline, prior to attempting this project.
Lift the rear of the Buick using a 2-ton jack or a jack with greater capacity. Place jack stands beneath either end of the rear axle beam, just inside the rear tires. The closer you get the jack stands to the outside of the car, the more stability you have in supporting the Buick for the duration of this project. If you decide to drive the back of the car onto wheel ramps, make sure it is on a level surface and that the ramps do not buckle at all under the weight of the car. Using wheel ramps to lift the rear of the car will eliminate the need for the jack stands.
Lay beneath the rear bumper of the Buick and slide your body so that you can physically access the bottom of the fuel tank. Slide the jack beneath the fuel tank. Place a length of wood -- 1-foot long, by 4-inches wide, by 1/2-inch thick or greater -- beneath the fuel tank. Raise the jack up to the bottom of the fuel tank, with the wooden plank between the fuel tank and the jack. Do not press on the bottom of the fuel tank with the jack and wooden platform, but rest the platform snug against the bottom of the tank to support it.
Remove the two fuel hoses from the rear of the fuel tank. The rubber hoses are held on with hose clamps. Remove the clamps with a 3/8-inch ratchet and socket. Pull the rubber fuel filler hose and the vapor hose off of the rear of the fuel tank by hand. Insert a flathead screwdriver between the end of the hoses and the fuel tank fittings if the hoses are stuck onto the fuel tank at all. Moving the screwdriver around between the two parts will remove the corrosion that bonds the fuel and vapor hoses to the fuel tank fittings.
Remove the fuel tank strap mounting bolts from the rear of the Buick, using a 3/8-inch drive ratchet and socket. The tank strap bolts are located just in front of the rear axle beam, and are mounted into the frame support. Adding a 6-inch extension between the ratchet and socket can allow you greater reach and more maneuverability to remove the bolts. Turn the bolts counterclockwise until the strap bolts and tank straps come free of the bottom of the car.
Lower the fuel tank about halfway between the ground and the bottom of the car. Give yourself enough room to physically access and be able to see the top of the fuel tank. Remove the two small fuel hoses leading to the fuel pump, using a 3/8-inch drive ratchet and socket. Remove the hose clamps with the ratchet and socket, and then remove the hoses by hand. Remove the electrical connector from the top of the fuel pump by pinching it between your thumb and forefinger, and pulling it free of the fuel pump.
Drop the fuel tank completely down on the jack and slide the fuel tank onto a large piece of cardboard. Placing cardboard between the tank and ground will ensure that you do not create any spark or static electrical charge while removing the fuel tank from the Buick. Slide the fuel tank out from underneath the rear of the Buick.
Place the tip of a flathead screwdriver against the corner of one of the vertically protruding, metal tabs. These tabs are part of the fuel tank lock ring. Hit the end of the screwdriver to turn the fuel tank lock ring counterclockwise. Continue this procedure until the fuel tank lock ring pops upward and free of the fuel tank. This lock ring is responsible for holding the fuel pump into the fuel tank.
Remove the fuel pump from the fuel tank by pulling it straight upward out of the tank. Twist the pump on a horizontal plain to clear the fuel tank level float of the lip of the fuel tank. The float is mounted on the side of the pump and can sometimes get jammed between the pump and tank during removal. The twisting motion will allow the fuel pump to become clear of the tank, followed by the fuel float. Remove the fuel pump from the tank and immediately place the old pump directly into a drain pan. Remove the rubber O-ring gasket from the top lip of the fuel tank.
Insert a small amount of petroleum jelly on the lip of the fuel tank. Install the fuel tank O-ring gasket onto the lip of the tank. The petroleum jelly will help seal the fuel pump and tank assemblies together, but also helps hold the O-ring in place during pump installation. Install the new fuel pump straight downward into the fuel tank, making sure that the fuel float enters the tank first. Turn the fuel pump prior to seating it onto the tank, so that the fittings on the top of the pump match the direction that the fittings on the old pump were facing. Aligning the fittings will help lessen the installation time underneath the Buick.
Install the fuel tank lock ring on top of the new fuel pump. Push the lock ring downward by hand while simultaneously twisting the ring clockwise to set it under the fuel tank lock tabs. Place the tip of a flathead screwdriver against one of the vertically protruding lock ring tabs. Hit the end of the screwdriver with a hammer to force lock ring to continue turning clockwise, until the lock ring tabs are completely aligned and beneath the fuel tank lock tabs.
Slide the fuel tank back underneath the Buick, making sure that the tank stays atop the large piece of cardboard. Slide the tank onto the fuel tank straps to begin aligning the straps under the belly of the tank. Lift the tank or angle the fuel tank so that you can set your jack and wooden platform back beneath the tank. Slide the platform and jack into the dead center of the fuel tank for proper alignment and placement of the tank during installation.
Lift the fuel tank on the jack and wooden platform about halfway between the bottom of the Buick and the ground. Install the electrical connector onto the new pump by simply pushing it on with your hand. Install the two small fuel hoses to the fuel pump and tighten the small hose clamps with a 3/8-inch drive ratchet and socket. You only need 15 foot-pounds of pressure to tighten the hoses thoroughly. This can best be measured by turning the clamps so they are snug, and then turning the ratchet 1/4-turn farther. Use the "snug-and-a-quarter" turn method to tighten both small hose clamps.
Raise the fuel tank up so that it is resting against the bottom of the Buick. Install the two fuel hoses onto the rear of the fuel tank. Use your hand to push the fuel filler hose and vapor hose onto the tank protrusions. Tighten the hose clamps with a 3/8-inch drive ratchet and socket, using the "snug-and-a-quarter" turning method again. Do not over-tighten hose clamps or you could damage the fuel hoses, creating more time consuming and costly work for yourself.
Align the fuel tank straps with the fuel tank mounting bolt holes. Insert the fuel tank strap mounting bolts by hand and start the bolts inward a couple of threads. Tighten the bolts upward using a 3/8 inch drive ratchet and socket, with a 6-inch extension. Tighten the bolts as tight as you physically can get them, as they are supposed to be tightened between 80 to 100 foot-pounds of torque. If you feel the need to use a torque wrench, tighten the bolts accordingly using the torque measurements provided.
Turn the key in the ignition to the "II" position or accessories position, without actually turning the Buick's engine on. Turn the key back to "Off" position after one second. Repeat this process between 4 and 5 times. This procedure allows fuel that has escaped out of the lines during the pump replacement, to reenter the fuel lines. Turning the key to the accessories position and back off primes the fuel lines up to the engine with fuel and fuel pressure to start the car safely. Start the car only after you have primed the lines no less than 4 times. Shut the car off after you let it run for a few moments to test the new fuel pump.
Lift the rear of the Buick up with a 2-ton jack or a jack with greater capacity. Remove the jack stands from beneath the Buick and lower the vehicle. Drive the car forward if you mounted the car on vehicle ramps for this project.
