Originally Posted By 6PakBee
I'll throw in my twocents I can't find where the original poster said he was using stainless or steel lines. The corrective action is the same regardless. If the fittings are leaking, unless the machining on the fittings is poor, the tubing flare is defective in some way. Otherwise the fitting wouldn't be leaking. I have a selection of stainless steel female fittings and with a GOOD tubing wrench and lubrication on the nut, I tighten the bejesus out of them. This re-forms the flare on the tubing so it will seal. Never failed me yet. As a note, I've only used stainless lines one time (brakes) and never again. I had to tighten them so tight to stop them from leaking I was afraid I would either strip the fitting or gall it. Again, just my twocents, feel free to do whatever turns your individual crank.


I know about stainless lines, they are hard as heck and hard to get sealed.
But not only that, but since you have to tighten them so tight the first time, the second time could be even tougher to get them to seal because the seat is indented from the hard stainless and sometimes they don't go back together exactly the same as the first time.

Mild steel on brass is the best sealing combo and longest lasting imo.

Stainless is more prone to cracking because it is so hard.