I have posted a few times now the questions about the Vanagon tank and it's behavior and the puzzle that surrounds it about it's inside, because I can't figure out how it gets plugged up not letting a drop of gas out, and having it happened to the one that I just installed the same.  
I got three responses of which one was the best, suggesting to exchange the outlet with the return line.  No explanation about the mechanism or the working of the inside or any procedure to follow to flush it out to have a new like condition.  
I think, I will keep on annoying for a while until I get a knowledgable response.
Zoltan