I looked at this thread a couple times and I am wondering what "upside down" is. The NPR box is verticle with the lines coming in from the back of the box. I had to lay my box back and my lines come from the under side now. I have not seen any issues with it so far. I have yard driven my truck and the steering works fine. It did take a few times working the srteering back and forth to get the air out. I think this may be what he is refering to as "upside down"