OK - am I missing something - my FASS Dumps back into the fuel tank by putting fuel back into the tank via the overflow hose. I can look down the filler tube about 6 inches and I can see the overflow entry point. Unless my memory has failed I thought I use to see fuel always being sent there. Now nothing... ... . if you have a FASS and can see the overflow - tell mw if it is returning fuel back to the filler tube.