new brake line/hose leaking

[sbcCuttY]

i got a 85 cutlass and i just put in a brand new 1/4" line going to the rear and its leaking from the the top of the nut ,...can anyone give me r\some reasons why that would happen? i got the line preassembled at the store..

 

[Bonnewagon]

Bad/sloppy flare job. Knick or scratch on flared surface. Nut not tight enough/crossthreaded. Single flare instead of proper double flare.

 

[Blake442]

I've seen that plenty of times both with new lines that were pre-bent and flared, as well as lines we custom made for a certain application.
First thing to try is to loosen them a bit, and re-tighten them. Most of the time that takes care of it as it just needs some help getting properly seated on the flare.