An Impala's fuel pump forces gasoline from the tank to the engine. It works electronically and the constant flow of the current eventually wears out the pump. Clogged fuel filters, which force a higher current, can speed up the pump's wearing-out process. Overheating also contributes to wearing out the pump, especially when you keep the fuel tank near empty. A broken fuel pump prevents the car from running, while a worn pump reduces fuel flow. You can replace the pump from the fuel-sender access panel in the vehicle's trunk.
Park the car and turn off its ignition. Put on rubber gloves.
Lift and prop up the vehicle's hood.
Locate the Impala's battery in the engine compartment. It is a rectangular box with a cover. Remove the cover.
Locate the battery's negative terminal, identified by a "-." Use the 1/2-inch wrench to unscrew the nut at the negative terminal. Remove the the battery cable from the negative terminal.
Locate the top fuse block on the passenger's side of the engine compartment. Remove the fuel pump fuse, which is the top, left horizontal fuse.
Open the fuel compartment on the driver's side of the vehicle, located toward the back.
Unscrew the fuel cap to relieve the tank's pressure.
Open the trunk.
Locate the fuel sender access panel in the floor of the trunk. Unscrew the panel's bolts with the socket wrench.
Remove the panel to expose the fuel pump.
Unplug the fuel pump's electrical connectors.
Loosen the clamp on the fuel line that connects to the pump, using a wrench, and disconnect the fuel line from the pump. Some fuel may spill out.
Remove the fuel pump.
Place the new fuel pump into the space below the panel.
Connect the fuel line to the new pump. Securely tighten the line's clamp.
Plug in the pump's electrical connectors.
Replace the panel and screw in its bolts. Close the trunk.
Replace the fuel tank cap. Replace the fuel pump fuse, reconnect the battery's negative terminal and replace the battery compartment cover. Close the vehicle's hood.
