Measure the OD of your existing tubing, it will either be 3/16" or 1/4"...like 3B I'm betting it's 1/4".
The 1/4 inch inverted flare nut has a 7/16-24 thread. So your brake hose will need a 1/4" inverted flare Female end at the frame to mate up with the 1/4" inverted flare nut.
Mike B
