Double Flaring - What am I doing wrong?

[Ramination]

Hey guys,

I had a brake line failure (scary - luckily still in driveway) on my old truck and am in the process of re-doing the whole system. My issue is that I am struggling to get a single good double flare. A couple weeks ago I did the rent-a-tool from AA, it was in really bad shape, and a cheap tool. I ordered a Ridgid 345 and that is what I am using now, but still struggling.

I think my problem is 100% because the 3/16" line is slipping in the tool, but let me tell you my process, maybe someone can point out where I am going wrong.

I have tried using the little tube cutting tool, and using a dremel to cut the line. I read that the cutting tool hardens the line and makes the bubble part of the flare difficult. I have had similar results with both methods.

Anyways, once I cut the line I put it in the jig like below, then use a file to square up the end. I file it down flush.





Once it is flush I clean up the ID. I have tried using the deburring tool on the cutter as well as using an exacto blade to clean it up and chamfer a bit.

I remove from jig and file the OD down so there is no burr and chamfer it just a touch, make sure die slides in nice and easy. See below.



Next, I put it in the jig again (with beveled side of jig up of course) and set the depth to the first notch on the die.



Then insert the die, put on the other half of the tool and crank the living piss out of it to get it as tight as possible.



Then I slowly tighten the top to make the flare, only going until the die touches the bottom of the jig and not cranking it too tight. My issue is that the bubble doesn't form, I just end up with this



You can see that it is moving in the jig. I am cranking it down on the side one (that does the tension) as tight as I can get it though. The one for the picture I put the jig in the vise and then tightened it even more.



I notice that the 3/16" hole in the bottom part of the tool is the only one not ribbed.

I have also tried adding a little brake fluid to the contact points as lubrication, I read somewhere else that it would solve my problems...it didn't.

I did some of the brake lines a few years ago when I swapped to one tons and borrowed a badass Ridgid unit and it worked flawlessly. I am unsure why I am struggling so much this time around. The tool is brand new, as are the dies. All brand spanking new.

Any suggestions or tips for me? Is there anything I am not seeing here?

Thanks in advance

[THX_138]

It looks to me like you've only completed 1/2 the process of a "double flare"

Cut line straight... Check ... You did that seemingly fine

Chamfer inside of line to somewhere around a 45* angle... Check... Anything close to less then a sharp inside will work

Place die upside-down beside line and set height... Check... You seemingly have done that OK

A slight dab of motor oil or brake fluid on end of line to ease the flare... You said you used brake fluid... It should have been plenty, just looking for something to help break the friction

Insert flare tool and crank till it stops... Check.. Looks like that went OK for you

Here is where I think you've forgotten the actual flare....
You've completed the "double" part of the flare with the previous steps, but before you remove the line from the jig you need to then loosen flare tool,
Remove the "doubling tool"
And now re-install the flaring tool with only the cone shaped end touching your line and crank it down as far as it will go all over again to create the actual "flare" on the end.


If your line is slipping in the holder, that's usually the sign of a cheap tool, but it doesn't sound like you have a cheapo tool.
You can always lay a piece of bicycle inner tube around the line before you clamp it on the line. That usually holds line even in the cheapest of brake flare tools

You did say "old truck"
Not sure how old the truck is, but you might run into a whole new set of issues if its actually a really older truck. Some of the old style brake components will leak if you attempt to connect double flared ends to the old single flare components.

If that's the case, just skip the little die tool in your first step and flare the line directly with the cone shaped flare tool.


Hope I helped.



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[Ramination]

Hey, thanks for the reply. I guess I should have specified but yes I only did half of the flare because the bubble part isn't turning out right, and therefore the final result is going to be trash so I just stopped there (I did multiple all the way through the process, none are satisfactory).

The "old" truck is a 97 Ram, everything I've seen it so far is double flare.



I am thinking of trying to put something on the brake line before I put it into the jig to increase the friction so it wont slip on me. Chalk maybe?

[THX_138]

Ahhh 97 is still brandy new all double flares on that for sure.

I think chalk might worsen the slip. I chalk my hands when shooting pool to get the pool stick to slide better on my fingers and hand.

I would first sand that crappy rust proof coating completely off a few inches of the end that they have on some new brake line (the one in your picture has it).
Or go buy some non-coated line.

That rust proof coating is just too slick for some brake tools

Cleaning it should be enough to stop the slip, but you can wrap it in something before clamping.... A thin rubber inner tube, a latex glove... Anything for a little added traction. I feel getting the coating off should be plenty.



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[Ramination]

Thanks for the help. Heading back out, will report results.

[Ramination]

Brilliant. Sanded off the rust proof stuff off and nailed it first try. I didn't have to break my wrists tightening the jig up either. Thank you!

[THX_138]

Originally Posted by Ramination

Brilliant. Sanded off the rust proof stuff off and nailed it first try. I didn't have to break my wrists tightening the jig up either. Thank you!

Happy I could be of some help.

I know that coating is supposed to help prevent corrosion, but man-o-man that stuff is a pure PIA




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