Hey guys,

My two brake lines going from the master cylinder to the junction box broke. These are the two lines right next to the fuse box under the hood. I removed the lines, and replaced with new brake lines using the same 4 brake line screws that came off the old lines. My question is do these lines need a special kind of flare? I have a standard brake line flare tool, and I have flared each end. However I am leaking brake fluid when I pump the brakes. Its leaking from in between the brake line and the brake line screw, which tells me the flare is not good enough. I took all 4 off again, and tried to flare them out more, but its still leaking.

Any advice is much appreciated.

Thanks!

Jeremy

 

You need what is called a double flare, not a single.

https://www.freeasestudyguides.com/b...utomotive.html

 

I'll have to give that a try. I don't have the small flare attachments, so I have always just used the flare vice tool, and the screw down tool for it, which of course would only make a single. Are single flares okay for other parts of the brake system? I've replaced other brake lines with only a single flare, and never had a problem. Mostly lines that go from front to the back. This is the first time I've had to replace the lines from the master cylinder.

Thanks in advacned. I'm going to pickup a new kit tomorrow that has the other attachments for making double flares.

 

You should always use double flare, much less chance of the nut fatiguing and cracking the flare. Plus tends to seal alot better. Are you using copper nickel, or regular steel brake line? Copper nickel is easier to work with, and approved for that use.

Double flare isn't the easiest thing to do. When it came to refurbishing my current truck, I called one of the brake line specialty shops and had them send me out the full line kit... Still had some issues, they didn't have a D60 rear template, so I sent them my originals. But it all worked out in the end, no leaks and it looks factory.

Don't know how well this one does, but they all look the same... Have $5 to spend?

https://shop.advanceautoparts.com/p/...E&gclsrc=aw.ds

 

 

 

Watched it. Only thing I'd do is add a very tiny amount of oil on the tool to line contact when you produce both flares. Do NOT lube the outside of the line, else it'll slip though the clamp and foul you up.

Its a good video, and the set he is using is snap-on - obviously not a $5 tool. But the design is the same. Good luck!

 

If you would much rater buy them vs make them you can get them made from stainless steel.
https://braketubes.com/

 

If you're trying to make a new brake line to replace a broken/rusted out brake line to get your truck going quickly, a good double flaring tool and some 3/16" steel brake line work great to take care of the issue. Just keep in mind that these trucks have gotten old and factory mild steel brake lines don't last forever. Since I plan to keep my truck awhile and I cherish a good stopping vehicle, I preferred to replace all of the brake lines on my truck with stainless steel pre-bent lines. It made the job easy and wasn't terribly expensive. The only issue I ran into with the stainless lines was that they required me to tighten the fittings more than I would mild steel brake lines, since the stainless steel lines are so hard, they would leak at connection points if they weren't properly tightened.

 

Stainless tends to fatigue/crack easier than steel. I choose steel for daily drivers, then just spray it down with fluid film - along with the rest of the underside. Figure if the originals lasted 15+ years, a replacement set with rust inhibitor on it should last me long enough.