The most common problems when removing a fuel tank from a vehicle are caused by leftover fuel and fumes creating dangerous working conditions, especially in indoor areas. Another common problem is causing a leak upon reattachment due to improper connection of the fuel tank assembly.
Whenever replacing or servicing a fuel tank, make sure that the work area is clean, organized and well ventilated. Keep a fire extinguisher at hand at all times to mitigate the risk of accidental fire. Additionally, there should be no flame sources or pilot lights nearby the work area.
Amateur mechanics who attempt to replace or service fuel tanks may forget to drain the fuel out of the old tanks before disconnecting them from the vehicle frames. Many fuel tanks feature a drain cock that allows the fuel to be neatly drained from the lowest point on the tank. If this valve exists, loosen it before working on your tank and drain the fuel into a safe receptacle before attempting to remove the tank.
Fuel tanks that do not feature a drain cock must be drained through the removal of one of the fuel lines feeding the tank. The hose that exits the tank at its lowest point is the safest choice in this instance, as it often connects the fuel tank to an electric fuel pump, fuel filter or hard fuel line. For the best results, photograph the tank before disassembly so that it is easier to put back together after the process is complete.