Power steering problems 2008 GT

Weeks ago my original power steering pump failed. I replaced it with a brand new, not-remanufactured pump. That one worked fine for a couple of weeks and then it started leaking from the shaft seal/bearings. I replaced that pump with a remanufactured pump. I also replaced the high pressure return line because I originally thought the fitting was leaking before I found the leak from the shaft. The power steering worked fine at that point.
This week I turned the car hard and gunned the gas and the pump made a loud squeal and the pressure went out. The power steering is gone except at extremely high RPMs now. I believe the safety valve opened in the pump for some reason.
I have never had this much trouble with power steering.
Does anyone know if it is possible that I have a clog in my steering rack that could be causing these problems? I do not want to have install another pump and have that one fail in a week. What else could be causing these issues that seem to be happening because of over-pressure in the system (i.e. leaking pump and the safety valve releasing)?
I need help.

That is the check valve on a Ford steering rack. This little piece of metal has cost me a lot of heartache and three power steering pumps over the past few weeks.

I took it out (I know Ford says it is required) until I can get the refurb rack I have put in.