The tank in a GMC Envoy stores the gasoline that the engine needs to run. These tanks sit low on the chassis, and they are susceptible to impact or damage from large rocks or impact in a collision. This tank also holds the fuel sending unit and fuel pump, and the only way to access those parts is to remove the tank from the Envoy so that you can gain access. Doing this takes about an hour or so to do.
Lift the rear of your Envoy with the jack and put the vehicle on jack stands. Put the wood block on the head of the jack. Lift the jack up so the wood contacts the bottom of the tank.
Unplug any wiring harnesses that you can reach on the top of the tank with your hands. Unbolt the mounting straps from the frame with the 3/8-inch ratchet, extension and sockets.
Carefully lower the jack down until you can access the top of the tank. Push in the quick release fittings on the fuel pump with your hands and then pull the lines off of the fuel tank.
Lower the tank down onto the ground with the jack. Slide the jack and the tank out from under the Envoy.
