I've been having a lot of problems with my 3.8L V6 the fuel pumps..
Just before installing the new pump, I checked the pprv by blowing air through one end but it doesn't pass. I know these valves suppose to block the fuel going back to the tank, but I checked it from the pump's end. I have no idea what to do, I'm afraid that's what making the pump work harder and killing them after a while.

I know I have posted about this before, but I just need to know if these valves supposed to be like this? I would greatly appreciate your guys' help.