Picked up an old metal 6 gal tank since my one with plastic gauge is cracked. When tank was filled and hose left off and cap put on tank pressure pushed gas out fuel supply nipple. I see the left pin is for the vent since there is hole below it in casting. I blew air in hole and pushed pin in and could hear air pulsing in tank so it is clear. Even with me pushing in the pin manually with cap tight it has gas come out nipple. I assume the pin on right side has worn seal in there and is letting fuel pass?I currently leave hose on when transporting it to keep it from doing this. Am I on the right track?