Carl,
What you describe is what was described to me by the vendor when I used all new stainless-steel lines and all new brass fitting.
"I very gradually tighten them up in order to feel the flare end of the brake line squish to match the contour of the fitting. I then loosen it and re-tighten it. You should notice that it takes less turning the second time."
The only thing I did differently, is that I loosened and re-tightened, 3 times - gently.
No leaks in 11 years.
