There is lots of “urban legend” stuff surrounding this subject… In most tank / pump designs, the actual pump is mounted high in the tank and is only submerged when the tank is full or nearly so. Since the fuel system constantly is returning excess fuel to the tank in a closed loop constant pressure system, the fuel flowing through the pump keeps it cool, if indeed it needs to be kept cool…This whole argument depends on the fallacy that in-tank fuel pumps are somehow subject to overheating when in fact I don’t believe that’s the case…
Overheating fuel pumps inside a closed gasoline tank are NOT a design feature that is built into these pumps. They don’t fail because they overheated. They fail because they wore out or the flex-lines that connect them inside the tank rupture and pressure is lost. Once fuel pressure is lost, the engine and fuel pump are shut down long before the pump “burns up”…