I'm working on a the manual brakes of my 57 88. I had to cut the steel line near the rear hose because the tube nut had seized in the old hose. I purchased a single 45 degree flare tool from O'Reilly and used it to re-flare the cut line to attach to the new rear hose. After this, I've read that most people say not to single flare a brake line. I'm still working on bleeding the system, but I don't see any leaks here yet. What's the liklihood this will hold? It's funny, the packaging for the tool showed it was for brake applications and the guy working there recommended it. Thoughts?

 

Correct, you aren't supposed to use single flares for brake lines. Brake lines use inverted flares or double flares. This is the tool you should have gotten from the auto parts store.

https://www.oreillyauto.com/detail/c...ol/pfm0/w80670

You can probably rent it and just return it when you are done.

 

x2, double lap flares only for brake lines.

 

As always, thanks for the information. Kinda annoying the tool says it's for brake applications.

 

You make double flares with the same 45 deg tool but need to use the additional mandrels to make the first step in the two step process.

 

Whether you need a single- or double-flare does not depend on the application. It depends on the material of the tube.

OEM steel lines on our old cars are seamed steel. When single flaring, this material can split at the seam, causing a leak. A double flare will not split.

Brake lines made of copper-nickel or seamless stainless can stretch easier than seamed steel without splitting; these do not require a double flare.

Just examine your single flares. If they did not split and there is no leak, you are OK without reworking the flare.