Plumbing pump on 76 Newell

[Capnted]

The plumbing on my '76 has been changed so many times I have no idea how it was originally done. I'm trying to plumb the pressure pump back in & can't figure out how to do it since there's no filler on the fresh water tank--just the hose that comes out the bottom. It fills & empties through the same hose.

All the diagrams i find show the logical solution--fill through the top & attach the outlet at the bottom to the pump. Is it as simple as running the water from the city water connection through the pump backwards? I have valves set up for that. Or do I need a valve to isolate the pump while I fill, then allow the water from the tank to flow to the pump by closing one set of valves & opening another? I hate to make it so complex that I need to consult notes before filling or using the tank. it seems simple when I'm thinking about it, but when it comes to actually running pipe (pvc) I don't see how it will work.

We've been living in the '76 for more than a year. It's been a good friend. We've been connected to city water til now, but plan to boondoggle a little on our way back to Florida from northern MN.

Thanks

Ted