The fuel tank in a 2000 GMC Sierra truck is located underneath the bed of the truck. The tank is held in place by two metal straps that bolt to the frame under the truck bed. The fuel tank contains an in-tank electric fuel pump and fuel-sending unit. In order to service the pump or the fuel-sending unit, the tank must be lowered. This can be a somewhat challenging job, but you should be able to detach your Sierra's fuel tank and drop it down right in your own driveway.
Turn off the engine and place the Sierra's transmission in park (automatic) or first gear (manual). Apply the parking brake and chock the rear wheels. Open the hood and disconnect the negative cable from the battery terminal using the battery terminal wrench.
Place a block of wood on top of the jack and slide the jack underneath the fuel tank. Raise the jack until the wood is touching the fuel tank. This will prevent the tank from falling when the straps are released.
Loosen the hose clamp on the filler hose that connects to the back of the tank using a flat-head screwdriver. Remove the filler hose from the tank. Disconnect the fuel line that runs from the tank to the fuel filter by pressing the plastic quick-release clip on the fuel filter. Remove the metric steel bolts that hold the tank support straps to the truck bed using a 1/2-inch ratchet and a metric socket connected to a ratchet extension.
Lower the jack slowly until the tank is free from the truck and resting on top of the jack near the ground. Disconnect the remaining electrical connectors and hoses from the fuel sending unit. Remove the tank from underneath the vehicle.
