OK, I'm new to the Chevy Tahoe world, but not to the mechanical world, and not without some skill. I've read everything I can find, on this forum, YouTube, the Internet, wherever I could find it, about how to do a double-flare on a brake line. No matter what tool I use(I have 2 different ones), and no matter what size line I work on(I've done both 1/4" & 3/16"), I cannot get the bubble thing to come up when using the appropriate die to start my flares with. It seems to press down into the well on the tools, though not very distorted into the shape that I think it's supposed to, nowhere near the bubble-looking result shown in many videos. I've followed(almost anally) the directions - cut it straight, clean up the burrs, get it straight in the tubing clamp, sticks out just to the shoulder of the die - pretty much everything, and more than once! No matter what I do, how I set it, how much or little sticks up, to lube or not lube - or even which tool I use - no bubble like it shows on all the nice videos. . . You want a single flare? I'm your boy! You want a double flare? Sorry, can't do. Since I've seen so many videos, both here and elsewhere, that seems to imply that most anyone can do a double flare, I'm feeling a little inferior . . . anyone else having problems with the double flare world? I can't believe that, with 2 different tools, it's the tool's fault, though that's certainly a possibility. I'm beginning to believe that the problem with this procedure is the tool operating the flaring tool. . . . Any advice or suggestions before I bite the bullet and have it towed to the mechanic?