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Help With Using Flaring Tool on Brake lines

Posted: Thu May 10, 2007 6:12 am
by Rileysowner
I almost have the brake lines done on my Sunrunner, but one of the precut lines needs to be trimmed down and the fitting replaced. I have a flaring tool kit and was practicing on some scrap brake line, but with little success. It seems my flares always end up lopsided. Now reading the instructions I need to cut the tube straight, not a problem with a tube cutter, de-burr it, not a problem with a de-burring tool, chamfer the outside edge (I had not noticed this instruction and wonder if that is the problem) but I am not sure exactly what needs to be done in this step.

Then put the tube into the flaring bar at the correct height based on the flaring adapter, insert the flaring adapter and put the yoke over it and crank down (this is where things go wrong is the correct adapter size 3/16"?) then take it out, crank down the pointed part of yoke to finish the double flare.

So, what should the chamfer on the outside edge be like? Any other help? I really want to get this job done as our Mazda Protege is running rough enough that I wouldn't want to go out in it. So we are down to the van only. That gets a little expensive on gas so having the Sunrunner up and running again would be great.

Posted: Thu May 10, 2007 10:07 am
by astrogurl
I know PJ did this on our blazer.....me, I'm as lost as you, but I will put PJ on notice, even though he is in Baltimore.

Posted: Thu May 10, 2007 10:36 am
by Rileysowner
Thanks, any help would be appreciated. My guess is it is easier than it seems once I know the trick to it :)

Posted: Thu May 10, 2007 2:08 pm
by astrozam
Here you go Jim,this link should help a little...
http://www.stu-offroad.com/suspension/f ... l/ft-1.htm

p.s,Hope your takin pics for a How To article

Posted: Thu May 10, 2007 3:02 pm
by SafariRob
Zammer, thanks for posting that link. Like Jim, I've never been able to get a decent flare on a brake line no matter what diameter the line was.
Work hardening, huh? That could be the culprit!
Wonder where I put my double flare tool after I got exasperated with the whole deal...

Posted: Thu May 10, 2007 4:12 pm
by Rileysowner
Thanks Keith, that may help. At least it makes things clearer. I will have to get back to practicing :)

Brake line flares

Posted: Sun May 13, 2007 4:49 am
by Smiliesafari
It's not necessary to double flare. All the line has to do is not leak. I've singled flared several times and never had a leak.

Posted: Sun May 13, 2007 4:55 am
by peter
For whatever it's worth, I had to get used to doubleflaring when building ZZ. I've been single-flaring copper since the age of 16, but double-flaring small diam. steel lines was a new one for me. Took me quite a few practice runs with small pieces, but I figured out that the most important part is to ream the inside of the tube before flaring.

Posted: Sun May 13, 2007 10:35 am
by Rileysowner
I gave up on the flaring as I needed to get the Sunrunner up and running so I went out to Napa and got another brake line that is preflared. This one had a fitting that actually worked properly, so although it isn't pretty, and there is an extra couple of inches of brake line that I would have trimmed off, I now have working brakes again.

I am debating keeping the flaring kit, but am not sure at the moment. I can bring it back for a full refund, but then it might be handy if (probably more likely when) I have to do other line.

I still have lots of extra brake line to practice on, so maybe I will try for a while first to see if I can get a good flare.