bought this to fix fuel drain back problem

well, it is like I said before guys. I am not a mechanic. But I do have common sense. I know that when I have a problem for 10 years and I change something and the problem is not there immediately after the change is made, I call it fixed. Dave, you mentioned earlier about ambient temp. and buying fuel at different locations.well, I am going to bust your bubble again. I live in a small town. Every week when I leave for a car show, the first thing I do is fill my tank for the trip. and you guessed it. I fill it at the same watering hole. and as far as the ambient temp. goes, it has not changed more than 5 degrees this year between having the problem and after fixing the problem. Not to say you are wrong about these things, just that is not the case here. As far as the check valves are concerned, have you ever heard the saying, " third time is a charm". This may not work for anybody else. I am just saying it worked for me. I am like Memike. I will not run an electric pump. I almost burned a car up back in the 70's because of that and I do not like them. I will let you guys know if anything changes. But for $9.00 shipped, what have you got to lose.