We got clean brake lines with our frame, so we are reusing those from the distribution block down, but need to make new lines from the master to the distribution block.
Research showed that these lines are 4 different threads, 2 metric, 2 std:
Bubble flares are new to me, some people say that the first step in the double flare process is a bubble flare, but that is actually not the correct geometry. They sell a bubble flare tool, but instead, we found these adapters to convert the master to 3/8-24 inverted flare:
https://www.pepboys.com/ags-brass-adapter-3-8-24-i-to-m10-x-1-0-b/product/143657
https://www.pepboys.com/ags-brass-adapter-3-8-24-i-to-m12-x-1-0-b/product/143633
If you have never done a double flare before, here are the steps:
Cut the tube to length, make sure the cut is square and de-burr the ID. Put the tube into the bar, stick out is determined by the height of the shoulder on the die:
Use the die to bulge the tubing, squeeze it until the die contacts the bar:
Then remove the die and roll the tubing back onto itself to complete the double flare. I have found that if you don't over squeeze this last step, it allows the flare to conform to the actual seat when you tighten the line in place.
And try not to forget the nut or you have to cut off your brand new flare and start over:
We used NiCopp tubing because it is very easy to flare and bend and won't rust:
