Multiple problems with bleeding brakes

Yeah it has a copper crush ring. When I installed the lines from the MC to the prop valve, I put the prop valve nut fitting at the top in the vise to ensure it didn't turn at all when I tightened the line to it.

After installing it and attempting to bleed the brakes, it started dripping from the crush washer. After that I held the body with a pair of pliers and turned the nut fitting on top and tightened it a good bit. Still leaked after that. So I went back and tightened it as much as I could and it continued to leak.