which surprised me because I just installed a new one a month ago, and the flange was not too tight. I took the Head apart and sure enough there was a permanent set of an open gap in the duckbill about 1/8" wide. Put in a new one, we'll see what happens, works great (again) for now. But yeah, these things should last longer than a month !

PS > I had installed a new pump air intake valve a month ago as well.

thanks again, cheers, John