The Audi A4 has gone through five generations since it began production in 1994. Models include the B5, B6, B7, B8, and DTM. These vehicles come with a variety of different fuel-injected engines. In all cases, the fuel pump sits partially in the fuel tank below the Audi. These models also feature an access panel behind the driver's seat that lets you reach the fuel pump quickly and without having to remove the fuel tank, a tedious process in itself.
Prop open the hood of your Audi. Disconnect the negative battery cable on the car battery. Locate the banjo bolt or Shraeder valve. Lay rags around the valve or bolt. Press down on the valve to release the fuel pressure, or loosen the bolt with your wrench to release the fuel pressure.
Remove the rear seats from your Audi. Pull up on the two tabs in front of and below each seat to dislodge them from the mounting tabs. Slide them forward and upward to pull them off of the seat stay and expose the fuel pump access panel.
Remove the bolts locking the fuel pump access panel to the seat stay with your socket wrench set. Pull off the access panel.
Disconnect the fuel and vapor hoses from the fuel pump nozzles. Disconnect the wiring connector from the fuel pump.
Clean the grime, dirt, and other particulates off of the top of the fuel tank around the pump so that no impurities get into the tank while you are changing the fuel pump.
Loosen the tabs of the locking ring from the slots of the fuel tank by striking the tabs with your hammer and screwdriver. Remove the locking ring. Pull out the fuel pump and fuel pump gasket.
Lubricate the new gasket with motor oil. Place it under the head of the new fuel pump. Set the new fuel pump in the fuel tank. Lock it into place with the retaining ring. Reconnect the fuel, vapor, and electrical lines.
Reconnect the negative battery cable. Turn the ignition key to the on position. Wait a few seconds. Turn the ignition key to the off position. Do this until the engine cranks. Close the access panel. Replace the back seats.
