How durable are 37 degree -AN connections?
07-17-2011, 07:14 PM
#1
How durable are 37 degree -AN connections? I have an aluminum trans cooler mounted in front of my radiator on an aluminum support beam. The cooler has -6 AN male ends. I was thinking about connecting those -6 AN end those to 3/8" steel brake line mounted to the chassis. Would that be a good durable connection?
On paper it sounds great - neither the chassis nor the trans cooler should move around because they're all bolted together. However, I know that chassis does flex for different reasons. I can see mine flex a little when I jack up one corner of the car. I'd imagine it flexes a little more when I go into a bend really hard, especially up front around the radiator, where there's not much connecting the two front corners of the chassis together.
Also, I'd put flexible line between the trans and the steel brake line, so no motion from the engine will be transferred to the steel lines on the chassis.
Anyway, is that something the 37* -AN setup can get away with? Is it tough enough, or will the seal/flare prematurely fail? The alternative would be some sort of compression fitting, but I'd rather not go that route.
On paper it sounds great - neither the chassis nor the trans cooler should move around because they're all bolted together. However, I know that chassis does flex for different reasons. I can see mine flex a little when I jack up one corner of the car. I'd imagine it flexes a little more when I go into a bend really hard, especially up front around the radiator, where there's not much connecting the two front corners of the chassis together.
Also, I'd put flexible line between the trans and the steel brake line, so no motion from the engine will be transferred to the steel lines on the chassis.
Anyway, is that something the 37* -AN setup can get away with? Is it tough enough, or will the seal/flare prematurely fail? The alternative would be some sort of compression fitting, but I'd rather not go that route.
07-17-2011, 08:56 PM
#2
The AN fitting you wish to use will be more than sufficient, they take lots of pressure and are very durable. There are several colors available to make things look nice also.
07-17-2011, 09:00 PM
#3
I have an aluminum trans cooler mounted in front of my radiator on an aluminum support beam. The cooler has -6 AN male ends. I was thinking about connecting those -6 AN end those to 3/8" steel brake line mounted to the chassis. Would that be a good durable connection?
On paper it sounds great - neither the chassis nor the trans cooler should move around because they're all bolted together. However, I know that chassis does flex for different reasons. I can see mine flex a little when I jack up one corner of the car. I'd imagine it flexes a little more when I go into a bend really hard, especially up front around the radiator, where there's not much connecting the two front corners of the chassis together.
Also, I'd put flexible line between the trans and the steel brake line, so no motion from the engine will be transferred to the steel lines on the chassis.
Anyway, is that something the 37* -AN setup can get away with? Is it tough enough, or will the seal/flare prematurely fail? The alternative would be some sort of compression fitting, but I'd rather not go that route.
On paper it sounds great - neither the chassis nor the trans cooler should move around because they're all bolted together. However, I know that chassis does flex for different reasons. I can see mine flex a little when I jack up one corner of the car. I'd imagine it flexes a little more when I go into a bend really hard, especially up front around the radiator, where there's not much connecting the two front corners of the chassis together.
Also, I'd put flexible line between the trans and the steel brake line, so no motion from the engine will be transferred to the steel lines on the chassis.
Anyway, is that something the 37* -AN setup can get away with? Is it tough enough, or will the seal/flare prematurely fail? The alternative would be some sort of compression fitting, but I'd rather not go that route.
07-17-2011, 09:22 PM
#4
Thanks for the info guys.
I am most worried about the durability of the flare. If that will hold up, I think I'll be okay. I've seen stuff like this done with inverted flare (45* double-flare) on vehicles from the 70's.
Why do you think the steel hard line to aluminum fitting is a bad idea? I guess there is a chance that the harder steel flare won't conform well to the aluminum male seat, resulting in a leak if the flare isn't perfect. If I go this route, I think I am going to take my steel lines down to the Parker store... the guy there makes some great 37* flares. I might look into aluminum conical seals (aka "flare savers") as well.
Thanks for the heads-up. I saw those compression to AN fittings that Summit carries. The fine print says they only want you using them with aluminum tubing. If I go the AN to tube fitting route, I'll probably get Swagelok or Parker A-Lok fittings.
I am most worried about the durability of the flare. If that will hold up, I think I'll be okay. I've seen stuff like this done with inverted flare (45* double-flare) on vehicles from the 70's.
Why do you think the steel hard line to aluminum fitting is a bad idea? I guess there is a chance that the harder steel flare won't conform well to the aluminum male seat, resulting in a leak if the flare isn't perfect. If I go this route, I think I am going to take my steel lines down to the Parker store... the guy there makes some great 37* flares. I might look into aluminum conical seals (aka "flare savers") as well.
Thanks for the heads-up. I saw those compression to AN fittings that Summit carries. The fine print says they only want you using them with aluminum tubing. If I go the AN to tube fitting route, I'll probably get Swagelok or Parker A-Lok fittings.
Personally, I would never use steel lines on aluminum fittings. OK though, as long as you transition from the steel brake lines to the cooler using a short hose with appropriate fittings. Be aware, the compression-to-AN fittings Jeg's & Summit sell are only rated for 50 PSI. There are higher rated fittings available from Parker, etc...
07-18-2011, 02:39 AM
#5
Steel brake lines are non-seamless. That means the only the outside is suitable for a mating surface. That's why they double flair (45 degrees) brake connections. I've only seen 1 hydraulic tool for doing double flair 37 degrees, but you can check with the Parker dealer..
07-18-2011, 05:41 AM
#6
TECH Fanatic
Don't worry about the flare. The problem can be present with any tubing. Make sure that the "bell" of the flare is concentric and free of burrs or voids in the mating surface. Use a proper 37 degree flare tool. My best suggestion is to use a b-nut and tube sleeve at the hard line termination joined with a male union to the flex hose. Over the years I have done hundreds if not thousands of similar connections with steel brake/fuel lines as well as aluminum and stainless tubing. I absolutely agree that at least one end of the steel tubing should have a flex joint to prevent work hardening and cracking of the tubing due to vibration.
07-18-2011, 07:49 AM
#7
Does it matter which end has the flex joint? I want to use flexible hose at the transmission end of the the steel tubing, but I also want to eliminate the flexible hose at the cooler side of the steel tubing, and run the steel tubing straight into the cooler. The cooler and the steel lines are both mounted to the chassis, and should only move if/when the chassis bends or twists around. Would that be okay?
Just some food for thought - my dad is restoring a 1974 Nova, and he has hard steel trans lines that go straight from the trans to the radiator, with no flexible lines at all. I was really surprised to see it done that way, but that is how it came from the factory. (see attached pic - I think they're inverted flare)
Just some food for thought - my dad is restoring a 1974 Nova, and he has hard steel trans lines that go straight from the trans to the radiator, with no flexible lines at all. I was really surprised to see it done that way, but that is how it came from the factory. (see attached pic - I think they're inverted flare)
My best suggestion is to use a b-nut and tube sleeve at the hard line termination joined with a male union to the flex hose. Over the years I have done hundreds if not thousands of similar connections with steel brake/fuel lines as well as aluminum and stainless tubing. I absolutely agree that at least one end of the steel tubing should have a flex joint to prevent work hardening and cracking of the tubing due to vibration.
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07-20-2011, 03:56 PM
#10
I did exactly this same adaption, but on my fuel system. 3/8" 45* flared brake line to AN-6 except I went directly to Twist-Tite push on high pressure hose. NAPA had the fitting in brass; 3/8" f'male flare to -6 (3/8") high pressure hose barb. I used the Summit blue hose, but Earl's, Aeroquip, etc all have the same high pressure push on hose available (and in various colors). In the photo, the fitting is just visible (has the arrow marked on it).
Andy1
Andy1
