I don't think sealing is the only reason for double flaring. The way a GM training school instructor explained it to me in a brake seminar that I attended, (back in the dinosaur days :grin: )......repeated tightening and loosening of single flared fittings cause the funneled end to crush and get smaller, risking the chance for it to push out of the fitting and leak or possibly pull apart. On a double flared end, you can tighten and loosen numerous times without that happpening. Could someone please correct me if I am mistaken? :Smarty:
Bill There is nothing wrong with doing your own flares. The issue is that they need to be done correctly. I have been doing them for years without any problem. You have to have the correct inserts and take your time and be sure there are no splits.
