Thread: Brake line Problem

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I am useing a lot of A/N fittings and double flareing everyhing. Should I use thread tape on all the fittings for added security or not worry about them. I don't want any brake fluid on my new paint

No, no tape or thread sealant used on AN fittings.

I have never heard of double flare AN.

When I flare the end of a brake line that I have cut to length instead of just flareing the end with a single flare I double flare all my ends for safety and for insurance against later failure.

Originally Posted by blwn31

I have never heard of double flare AN.

can not say that I have heard of that one either

No thread tape or thread sealant should be used on brake lines at the AN fittings or any "standard" brake fittings. Thread tape can be used on any tapered pipe threaded fittings because the "seal" is made by the tapered fit of the threads.

Standard brake line fittings use a 45 degree double flare to seal.

AN fittings use a 37 degree single flare to seal.

The seal is carried out by the angled fit; not by the threads.

AN fittings (37 degree) are not interchangeable with standard fittings (45 degree) to create a seal.

I have never seen a double flaring tool made for AN fittings. How are you doing this?

Roy, go into the Russell, or Aeroquip on line catalogs and spend some time with the good info there. If you double flare SS lines you will weaken them. Also AN fittings don't use double flares and take special 37 degree tools like these.

http://www.russellperformance.com/

http://hydraulics.eaton.com/products...E-MC001-E2.pdf

Roy, I work on Large Aircraft I.E. Boeing 747, 757, 767, Airbus A300 and DC-8's. These manufacturers use single flare AN. I don't think you need to worry about the safety issue with AN. I think you may need to rethink what you are doing. Just my 2 cents, good luck.

Keith...

If you double flare AN fittings, you WILL get brake fluid on your new paint.

I guess the majority is going to rule on this one. Now I have to re-do all my brake lines. I have been double flaring all my brass and steel fittings just like they do at the factory with my hydraulic tool from MP Brakes and useing 45 degree. Then with the A/N fittings I have I slide the nut on the tube then the piece that goes through the nut and then I double flare the end with my 37 degree anvil. (NOT GOOD HUH?) I guess the single flare on the tube along with the littlle insert under the nut makes it just as strong as a double flare? Thanks guys

The double flare 45 degree SAE fittings are for steel brake line tubing. The single flare 37 degree AN fittings are for stainless brake line tubing.

If you double flare stainless tubing, the flare's will probably crack because the material is not as malleable as regular steel tubing. If you use 45 degree double flared steel tubing with 37 degree AN fittings, you'll probably have leaks. If you use 37 degree double flared steel tubing with AN fittings, It just might work, but that's not the way the fittings were designed to be used! Can you really get a nice tight 37 degree double flare? I've never tried that combination! The 37 degree flaring tools I've seen don't have enough room inside the tool to allow the double flare button to fit!