[Solved] Water fill leak - '95 Roadtrek 190 Versatile Dodge

You may need to drop the tank.
If you purchased it with the promise (hopefully a written guarantee) that all systems were working, I would take it back to the dealer, and have them fix it.
FYI about the Rt systems. They would often make changes, sometimes during the same year. You may find small differences in your Rt from other of the same year.