Originally Posted by VinceU
The pic Herk showed you is a "gravity fill" connection. What you are describing is a "pressure fill system" where the pressure hose is hard connected, you switch a valve somewhere nearby and the tank is filled with a pressure tap, often through the pump suction. There is an air vent attached to the tank top but careful its only designed to expel air, if you overfill you can damage the tank.
There is no 'valve somewhere' to switch, or pump suction. It fills the Fresh water tank with a screw on garden hose. Fill it up slowly or the water volume in will be more than the air volume going out and cause the tank to bulge. When the tank is then full of water the bulge will push the water out of the air over flow and cause a suction to form on the over flow tube and half of your water will be sucked out of the Fresh water tank. Some one may have to realign your air tube, it is a very very poor design and Forest River should be ashamed of it. Why is it on like this? It is cheap and easy, but still not functional. 'My' 'Dealer' realigned my air tube, but it still does not work as it should. I ended up having to mount a shut off valve on it and open it when I am to the camp site. 'If' you get the water to stop flowing after filling the tank and not have a valve on it, going down the road, gallons will still slosh out. When I get to the camp site and open the breather valve, water that is in the tube will start a suction action, I sometimes have to get under the unit and blow back into the tube to 'clear' the tube of water. Not the ideal situation, but a work in progress of having water in the tank and not loosing most of it.