Gas tanks need removal for various reasons. They can become contaminated with water or some other substance, in which case they have to be removed and completely flushed out so that no damage is done to the engine. Old gas tanks can develop rust and sediments that can clog the fuel filter and will need removal and replacement.
Move the hydraulic jack under the center of the gas tank and close the hand valve.
Lift the jack up to even with the gas tank so that when the straps are removed, the hydraulic jack will support the tank's weight. (If the gas tank has a drain valve, drain the gas before completing this procedure).
Loosen the screw clamp holding the fuel-line connecting hose in place with the large-bladed flat-tip screw driver. Turn the screw counterclockwise to loosen.
Place a drip pan under the fuel-line hose to catch any residual fuel in the line. (Wear safety classes at all times during these procedures. Gasoline is a serious eye hazard).
Loosen and disconnect the fuel inlet line from the gas tank by turning the wrench clockwise and holding the fitting still with the crescent wrench.
Select the appropriate size impact socket that matches the bolts holding on the gas-tank retaining straps.
Attach socket to impact wrench and wrench to shop air.
Loosen each retaining strap bolt by squeezing the impact wrench trigger set to counterclockwise rotation. Loosen bolts evenly so that the weight of the gas tank settles evenly onto the hydraulic jack.
Remove all four retaining strap bolts and remove them from your work area.
Lower the hydraulic jack by turning the hand valve slowly so that the gas tank comes down on the jack evenly.
Pull the hydraulic jack with the gas tank on top, slowly out from under the truck.
Set the gas tank top side down on the opening of the hazardous waste container. Allow all gasoline to drain out before making repairs.
