do you guy fill that section with diesel before you plug it up? Since it's relatively short and it is in a vertical deadend position. if you plug it up right after you install that section then a little bit of air will be trapped in there. right? I usually do that section after I finish the loop, fire it up and shut down. install that section crank it and then plug it up.
May be a little air won't hurt since it's a return line?
