I took my dad (neck brace, can't drive) to get gas, and as we were leaving the house, I noticed a gas smell. At the station, dad quit fueling when he saw a puddle of fuel under the truck. I hunkered down and looked; the entire bottom of the fuel tank was wet with a few little drops falling. I fired her up so we could come back home, and a steady trickle of fuel started pouring down from somewhere upstream from the tank. The truck runs fine; it just leaks gas when it's running. Any ideas on the cause? I'm thinking split fuel line or something. Thanks.