[gmachinz]

Thats not a flare union. Its a compression union which I wouldnt use on any brakeline. Those are compression nuts on both ends-if it were an actual flare union, each end would be a tube nut threaded into a much longer union. Judging by the pita of the immediate area, I can see why the PO opted to go the easy route instead of pulling a whole section of line out, then bending/flaring as needed for a proper repair.