Upper hose is collapsing!

It is NOT the radiator cap unless I am the unluckiest person alive & I have managed to buy 2 different radiator caps made by 2 different manufacturers from 2 different auto parts stores, having different lb ratings. Bought another brand new 16 lb cap, installed it when I got home today, ran the car up to temp, shut it down & when I went back out a few hours later the upper hose was attempting to turn itself inside out again. It is a brand new radiator, is it possible it is bad? Tomorrow I am removing the t-stat & buying another upper hose & trying it again. I can't possibly be the only person that has ever had an upper hose collapse from vacuum as a car cools down. I have a cheap aftermarket overflow that is not pressurized in any way also if that makes any difference. I will post as I try different things while I hope someone that has had this problem finally happens upon this thread. I am also going to try asome local rad shops tomorrow for advice. Thanks guys for trying.