leaking brake valve

You may just not have held the lines straight into the while tightening. A lot of guys will just get the threads started on the hex nut and then depend on the nut to somehow keep the line straight as it is pulled into the reverse flare on the valve/block. You need to loosen these up a couple of turns, and then hold the line with one hand so that it is straight into the inverted flare, while using the other hand to wrench down the nut. Once it is pretty firmly tight, then you can let go of the line, and apply the final torque. Sonce thse have been seated, this may not work so well now; and you may hae to torque the snot out of them.

My son and I used Inline Tube parts; I held all my lines straight while tightening and had nary a leak; my son did not know to do this and we had 2 leaks. It took a LOT more torque than normal to get them to stop leaking once they were put in 'non-straight'; I was waiting for them to strip out, but they finally stopped leaking and have been good since June.