kaptkronos, You are suppose to have a rubber fuel filler to tank hose - not metal. There should be metal hose clamps on both ends that attach the rubber hose to the metal filler tube and the fuel tank. If these clamps are not tight or have slipped off the tank or filler tube connections, then they would leak. If the rubber hose has a wear spot that has worn through the hose, then the entire hose should be replaced and new clamps installed, after finding and repairing whatever caused the hose to rub and wear a hole through the hose.
I see you are in Dallas, TX so if you need a new hose take your old one to:
GT Southwest Hose
644 W. Mockingbird Lane
Dallas, TX 75356
Toll Free 1-800-966-1393
They will be able to supply you with the correct hose and clamps for your rig.
Good luck - Glenn
2004 Safari 31SBD TREK W-20