What's the proper way to adapt steel fuel line to aluminum AN hardware.
 

What's the designed way of doing this. Some folks use an aluminum ferrule with steel line, but I've tried this with brass fittings and the brass ferrule won't compress the steel fuel line, I can pull the line out of the compression fitting. I'm thinking the hard line needs to be flared 37 degrees to adapt to the AN hardware.

Yep, thats the best way to do it. If your talking about the factory line on the frame, it'll be a bit tough to get at, but once you have a standard flare fitting, there are adaptors available that are flare on one end and AN at the other. Real common on brake line conversions where you need to hook up AN braided line ends to a factory brake line.

Don't know of a way to go straight to a AN fitting, though.

Hans

You have to flare it with a flare tool. I have several aluminum AN fittings on steel line. Slide the tube nut on, then the tube sleeve, then flare it.

If the flare splits the steel when you do it, you may have to double flare it, just like in a steel brake line.

you might consider a bulkhead adapter in the top of the tank and a new (bigger) line inside the tank...at least thats the way I would do it!
...redvetracr

Thanks Guys.:cheers:

You can't flare a 5/16th line since that would be a -5 AN fitting, non existent. You'd have to have a 3/8 OD line. If you have a 3/8 line a set of tube sleeves and nuts, a flare tool and you're in business.

Then there's the flare tool, the el cheapo ones only do single flares. They are only suitable for high quality seamless tubing or low pressure applications. Otherwise you'll need a double flare (you can use non seamless then since you effectively turn the tubing inside out)

I have a very high quality mil spec flare tool that does single and double flares even in stainless...it's a VERY expensive tool to buy (you can buy a neat welder for the money that a proper 37 double flare tool costs). This is it, a papco flaring tool...It flares from 3/16th all the way to 3/4th OD (And I used it to flare -10 AN alu lines, -6 lines, -4 and -3 stainless lines)
http://i5.tinypic.com/20rp6oh.jpg

You can flare (37degree) a 5/16 line .The tube sleeves and nuts are readily available. I have them on my return line on my 1980 Corvette. You would then need an adapter to convert from -5AN to -6AN.

I have a Harbor Freight double flaring tool. It's a cheap POS, but once you get the hang of it it makes perfectly acceptible, well-sealing flares.

Thanks Batman but I need to make 37 degree flares in some 3/8" stainless fuel line. I doubt Harbor Freight would carry this specialty tool. I do shop there though and have lot's of their POS stuff.:cheers:

There is another solution that works very well but a bit more pricy. Look up a company called Swagelok and find a distributor in your area.

Swagelok makes fittings that go on cut tubing and use a double ferrule that forces itself into the metal of the tube. These things will not leak at all! This eliminates the need for flaring.

I've used them for converting 3/8, 1/4 and 5/16 tubing into AN braided hose.

FYI I came across these working on lazer systems that required leak proof sealing after multiple dis and reconnects.

where did you get them and the 5 to 6 adapters?

Swageloks do work very well, I have them on the pressure side of my turbo oil plumbing. They aren't cheap though.

There are #5AN nuts & sleeves available at Summit. 5/16 tubing will fit inside of 3/8" tubing snugly, assuming the 3/8' tube is the common wall thickness found at most auto parts stores. You'd just silver solder the two together.

Here are the part numbers for the -5AN stuff at Summit. Union reducer(-6AN to-5AN) steel......AER-FBM2755. Tube nuts (-5AN)steel.....AER-FBM3571. Tube sleeves (-5AN) steel......AER-FBM3679. The above mentioned items are also available in anodized aluminum as well (EARLS) at Summit.