The Buick Century name has been around since its introduction in 1936. The Century had an on and off production history that ended in 2005. The 2003 Buick Century was produced with a 3.1-liter V-6 engine, capable of making 175-horsepower and 195 foot-pounds of torque. The fuel system on the 2003 Century is an electronic fuel injected system. The electronic fuel pump feeds the fuel system, while the fuel filter removes microscopic particles from the fuel that could possibly harm the engine.
Lift the rear of the Century in the air using a 2-ton jack or one with greater capacity. Place jack stands beneath the rear suspension beam just on the inside of both rear tires. Using vehicle ramps to back the Century onto will eliminate the need for the jack and jack stands.
Open the fuel door on the Century. Remove the gas filler cap in order to relieve excess pressure from the fuel system. Open the hood of the vehicle and disconnect the negative battery lead from the battery, using an open end wrench to loosen the battery lead.
Lay beneath the rear bumper of the Buick and slide your body so that you are positioned directly underneath the fuel filter. The fuel filter on the 2003 Buick Century is located just in front of the fuel tank, bolted to the frame of the car.
Slide a drain pan beneath the fuel filter location. Insert a GM fuel filter removal tool into the fuel line, on the clipped end of the fuel filter. One end of the filter is clipped directly into the fuel line, while the second end is threaded together. Push the fuel filter tool into the fuel line to release the clip located inside the line. Pull the fuel filter out of the fuel line with your other hand. Allow the fuel filter to drain fuel into the drain pan, while the residual fuel pressure from the system is being let out.
Place one open end wrench on the hex head end of the fuel filter. Place second open end wrench on the hex head end of the fuel line. Push the fuel line wrench toward the front of the vehicle, while pulling the wrench on the fuel filter toward the rear of the Century. Pushing the ends of the wrenches in this direction will loosen the torque between the two joined ends. Continue this "scissor" like motion with the wrenches until the threaded end of the fuel filter comes free of the fuel line.
Remove the fuel filter mounting bolt from the bracket that is wrapped around the fuel filter. Use a 3/8-inch drive ratchet and socket to turn the bolt counterclockwise with one hand. Grip the fuel filter in your other hand so that it does not fall in the drain pan and splash gasoline onto you. Remove the fuel filter completely from the Century. Place the fuel filter in a drain pan for no less than 12 hours prior to disposing of the filter in your trash can.
Hold the new fuel filter against the frame of the car. Insert the fuel filter mounting bolt through the attached fuel filter bracket, and into the mounting hole in the frame. Tighten the fuel filter mounting bolt with a 3/8-inch drive ratchet and socket, between 25 and 30 foot-pounds of torque. You do not need to over tighten this bolt.
Align the threaded end of the fuel line with the new fuel filter. Start the line onto the filter by hand, by turning the fuel line connector clockwise. Place an open end wrench on the fuel line connector, and place a second wrench on the fuel filter end. Turn the fuel line connector clockwise while holding the filter still with your other hand. Tighten the fuel line to the filter using approximately 40 foot-pounds of maximum torque. Do not over tighten the fuel line, or you risk damaging the internal threads in the line, rendering the fuel line useless.
Align the second fuel line with the fuel filter. Push the clipped end of the fuel line directly onto the fuel filter until it snaps into place. Test the connection by applying about 10-pounds of pulling force on the line to try to remove it. Remove the drain pan from underneath the car when you are done testing your connection.
Reinstall the gas filler cap and shut the fuel door on the Century. Reattach the negative battery lead to the battery, and tighten the lead using an open end wrench.
Set the vehicle on the ground in the opposite manner in which you raised it. If you used jack stands, lift the vehicle with the jack and remove the stands. If you used vehicle ramps, simply drive forward off of the ramps.
