stainless steel brake lines and AN fittings

[NickP]

Also, an FYI for the tool mentioned here; a drop of 3 in one oil is a great help on making 3/16" AN Brake lines (Double Flare). As an aside, I keep at least 3 of the mandrels in house in case of a failure.

http://www.toolpan.com/Mastercool-71...3_a_7cMAS71098


71098
37˚ FLARING & DOUBLE FLARING ADAPTER SET


Includes: 3/16, 1/4, 5/16, 3/8 and 1/2” dies 3/16, 1/4, 5/16, 3/8 and 1/2” double flare adapters and 37˚ Cone.


71098-01 37° Cone
37˚ Double Flaring Adapters & Die Sets
71098-03 3/16” Double Flare Adapter 71098-13 3/16" Double Flare Die Set
71097-04 1/4” Double Flare Adapter 71098-14 1/4" Double Flare Die Set
71097-05 5/16” Double Flare Adapter 71098-15 5/16" Double Flare Die Set
71097-06 3/8” Double Flare Adapter 71098-16 3/8" Double Flare Die Set
71097-08 1/2” Double Flare Adapter 71098-18 1/2" Double Flare Die Set

[Double Nickel]

Same kit that I bought from Inline tube when I made all my stainless lines. Double flared them all and no leaks. Also looked at aluminum fittings and was told by Earl's and a few other that I should not use them for brakes, especially with a high pressure system such as Hydra Tech or ABS Power. I used the steel fittings rather than the aluminum ones and used Earls hoses the the calipers as their's were the only ones that were DOT rated.

I was told the aluminum fittings can crack.

[chevynut]

I don't believe anyone has said to use aluminum FITTINGS in a brake system. Paul asked about using aluminum b-nuts and sleeves. I personally don't believe either would be a problem, however.

I tried to find info on pressure ratings of aluminum fittings, but couldn't find any. I'm pretty darn confident they'll take the 1500 pounds or so in a brake system.

Here's some information that suggests 3/8" (-6AN) 5052 aluminum tubing with .035" wall should take 2400 PSI. Aluminum fittings have a lot thicker wall than that and are usually stronger 6061 aluminum. And smaller tubing will take more pressure than larger tubing with the same wall thickness.

http://www.eng-tips.com/viewthread.cfm?qid=203900

"In hydraulic systems, 5052-O aluminum alloy tubing that conforms to Federal Specification WW-T-700/4 is used for reduced pressure (1,500 psi maximum) and return lines. For high-pressure lines (3,000 psi), MIL-T-7081 aluminum alloy tubing (6061) is in considerable use."

The above is for TUBING, not fittings which have much thicker walls. IMO I wouldn't hesitate to use aluminum fittings for a brake system given this info. Seems like there's a lot of FUD out there about this.