Here's how I understand it. THere is a propane bleeder valve up above where
the big thing fits on to fill (intake). To fill with propane, one opens the
bleeder valve be turning it counterclockwise and when the liquid propane
(whitish color) gets to the top of the tank, it will come rushing out the
bleeder valve and they know it is full, and then they should screw in the
bleeder valve clockwise to close it again. I agree that most of these guys
are idiots and I have tried to learn my knowledge from more experienced
types and it has been a while for me too but I think that is the deal.

Michael Schiesser
89 Westfalia
Seattle