The Stovebolt Site Forums The Shop Area Driveline Brake line flare problems

Dongray, with the slight crease on the underside of the flare it will put uneven pressure on the actual sealing surface of the flare. The better the flare the easier it will be to tighten it and achieve a leak free joint. If you were working with copper it would form quite easily, the steel or copper-nickel is harder metal and will take a lot more pressure to make the nut squish the sealing face. The flare nut has a matching angle inside of the nut to correspond with underside of the flare and that needs to have a pretty good surface to apply even pressure around the circumference of the flare. Don't get frustrated, keep practicing and you'll get a good feel for it. It's much easier at the work bench to make it right instead of under the truck with brake fluid dripping down your arms.