C2 Flaring Stainless Brake lines

[Joe Gushen]

I changed all my brake lines to stainless steel on my 66 Convertible. What I also did for safty reasons was to switch to a dual master cylinder. What I need to do to keep it neat at the master cylinder is to shorten the lines and flare two ends.

I was told flaring Stainless is very tricky. Problems with cracking? Double Flares? I've put on a few single flares on regular steel line without any problem. Do I need a special flairing tool? How and why would you do a double flare? What is a double Flare?

Every one claims it is problematic, but yet no one every said that they did it.

Any hints, tips, instructions would be helpful.

I apologize to the purist, but this is a high quality driver and I had braking problems in the past. Easy to change back.

I also would like to thank everyone for thier help with all my questions in this forum.

Thanks Again!

Joe

[Joe R.]

Re: C2 Flaring Stainless Brake lines

If you take a look at the flares on one of your old steel lines (assuming they were factory installed), you will see that the flared portion is actually two layers of metal. The flare is made in a two stage process that folds the flare over on itself. This is very important for getting a good, strong lip that is less likely to crack or leak.

For regular mild steel tubing, it is easy to make double flares using a simple hand tool that is designed for the process. It just takes a couple extra steps with the appropriate shaping dies. I have such a tool and have often used it for mild steel tubing, but I have never tried it on stainless tubing. From experience, though, I do know that the stainless brake lines are much less ductile.

If you want to avoid making your own stainless brake lines, one option that you might consider is to convert your setup 100% to the 1967 arrangement, so that you can use the standard stainless steel lines that are made for 1967 Corvettes.

[Joe L.]

Re: C2 Flaring Stainless Brake lines

Joe------

Brake lines should always use tubing ends which are double-flared. This process makes for a much more reliable and durable connection. With a brake system, reliability and durabilty are two of the most important functional parameters.

The only tools available for applying a double flare to stainless steel brake tubing are FAR more expensive than most hobbyists are going to want to spend. I'm talking in the range of $400+. I don't think that you can rent one of these tools, either.

While I am a BIG fan of "stainless steel anything", I don't recommend the use of stainless steel brake lines, even if you can purchase all of the ones you need factory-flared with fittings. That's because of the fact that stainless is very hard and lacks "conformability" at the flare-to-seat junction. This often produces leaks which may be hard to get stopped. The application of excessive torque to the tubing nut in an attempt to quell leaks can result in stripped threads. Then, you've got even more problems.

TBW (tinned bundy weld) brake lines work quite well. They are not as impact-resistant or, obviously, as corrosion resistant as stainless steel but they are "tried-and-true". Likely, they are going to last FAR longer than any of us are going to need them.

[Jason B.]

Re: C2 Flaring Stainless Brake lines

Joe,

I changed all of my brakes lines to stainless steel on my 65 Convertible a year ago. Just as you mentioned, the master cylinder was also changed to a dual circuit. Heard all the same things about stainless steel lines as you, that they're very tricky to work with on your own. But I went ahead and purchased a double-flaring hand tool from NAPA, shortened my stainless lines, and applied my own double flare ends. (a single flare and just bell-mouths the end of a line, a double flare bell-mouths the end and then folds then folds the edge back into itself so the actual flare is two layers thick and there is no raw edge exposed) I was just patient and tried a few practice double flares on the sections of line I cut off. It helps to warm the lines to soften them a little bit, not anywhere near glowing cherry red, just a little bit of heat.

Good luck with the project, I know it can be done at home.

Jason B.