Flares for AN brake fittings

[4redno]

I am in the process of restoring a Lotus 69 formula ford. The car has lots of British fittings which I am thinking about switching over to AN. I need to buy/rent a flaring tool for the hard brake lines and I have been told I MUST double flare the ends. However, it seems that there are almost no double flaring 37 degree tools - only 45 degree tools.

Aircraftspruce have one VERY expensive tool for doing 37 degree double flares but it is designed for copper/aluminum tubes and not the Bundy (mild steel) tubes I need to use.

Does anybody double flare their 37 degree AN hard brake line ends? If so, what tool have you used to do so?

Please advise....Keith

[Craig Henry]

ATS has them relatively cheap and they are a great company.

Craig

http://www.aircraft-tool.com/shop/de....aspx?PageNo=1

[Brian]

I have done several cars with 100% success using single 37 deg flares and AN sleeve and tube nuts. All of my research said that for -3 bundy tube, single flares were correct. That was years ago, but I've seen nothing to make me change my mind.

Mind you, I am not a certified airframe tech, just a race car guy.

Brian

[Rick Kirchner]

I second Brian's opinion. Shoot, I even use a 45 deg tool, stop short, and then tighten the B-nut and flare bushing onto a stainless fitting to finish the job.

I've never had one leak.

[4redno]

Several reliable sources have now told me that it's fine to use a 45 degree double flared end with AN fittings because the flare gets squashed as reqired to seal the system when you tighten the nut. I'm going to use a good 45 degree double flaring tool and call it a day because that's what integrates best with some of the existing, unique tee fittings on my car. If I were abandoning all existing plumbing, I'd go with 37 degree single flared ends, sleeves and couplers and use the Ridgid 37 degree single flare tool as it looks really good and reasonable.

Thanks for the feedback all. On to the next challenge.

...Keith