AN fittings

[CopperBronco]

Quick question about AN fittings, making my own braided lines with AN fittings for first time. Can anyone confirm the following?

You’re supposedly meant to leave a 1/16” gap between AN fittings when you tighten the two pieces together onto the braided hose? Any risk of leaks since I tightened down flush, and then had to back off 1/16”?

Second for NPT/pipe thread ends you should use high heat thread sealant or 2-3 wraps of Teflon tape, and aim to get at least the width of the bolt into the fitting as you tighten down, usually 4-5 threads minimum.

Lastly for the flared 37 degree AN fittings, you shouldn’t use any Teflon tape or thread sealant as the angled flare is what is sealing up, not the threads. Some say add a little oil, do you just use the type of oil that will be running through lines? In this instance it’d be trans fluid, as these are my trans cooler lines.

Many thanks, just trying to do this right and avoid leaks.

 

[Broncobowsher]

I've never left a gap. Typical install is to push the hose into the nut and visually confirm it bottomed out. Mark the hose (sharpie or piece of tape) to show a witness mark if the nut moves in the next step. Screw the hose end into the hose/nut (light lube on the threads, ATF when doing cooler lines is perfect) until it bottoms on the nut. Double check that witness mark that the hose didn't push out as the hose end was installed.

Paste or tape, different products for different uses. In systems that have precision controls in them (ATF, power steering, fuel system) I avoid tape. The threads that unravel can contaminate the system. It will never dissolve and go away. So I typically use paste, and fairly light. NPT is a tapered fit. The teflon is mostly a lube to allow a tight fit of the tapered fitting, filling some voids along the way. As such Teflon tape/paste is only to be used on NPT threads. Teflon tape is fine for shower heads in the house and heater hose nipples

AN fittings are two machined faces being pressed together. No sealer should be used on them.

 

[MarsChariot]

Ditto. But also to be clear AN is a hose fitting type whereas PTFE is a hose material. You can use PTFE AN lines and fittings as well as PTFE hose in regular other types of usages. So the reference to either/or was confusing. Also, if you are doing fuel you will want to use PTFE in an AN fitting. Otherwise you will be doing the hose again in about 5 years. Many of us know this from sad experience. AN rubber hose is o.k. for short hoses, but long hoses do not last.

 

[CopperBronco]

I had referenced this guy:

, I thought he said don’t mix AN fittings with PTFE hose, use PTFE fittings with PTFE hose only, or did I misunderstand something? Thanks for the help!

And this:

https://knowhow.napaonline.com/know-how-notes-braided-hose-end-guide/

Sent from my iPhone using Tapatalk

 

[CopperBronco]

I had referenced this guy:

, I thought he said don’t mix AN fittings with PTFE hose, use PTFE fittings with PTFE hose only, or did I misunderstand something? Thanks for the help!

And this:

http://[URL]https://knowhow.napaonline.com/know-how-notes-braided-hose-end-guide/

[/URL]


Sent from my iPhone using Tapatalk

Let me correct myself, compression fittings, the ones with the olive are usually used with PTFE hose, you are correct, I got my lingo wrong!

 

[jamesroney]

Let me correct myself, compression fittings, the ones with the olive are usually used with PTFE hose, you are correct, I got my lingo wrong!

If you are listening to those guys that you posted...then you lingo is going to be wrong forever.

I just wasted 22 minutes of my life watching the YouTube that you linked. It is a Motion Raceworks video, recorded by someone that has a VERY limited knowledge of hoses and fittings, and he is peddling the Fragola product line, which sources parts from lots of vendors, and it looks like they are re-branding Parker hose.

One thing to note about hoses and fittings is that every industry or market segment THINKS that they are right. And they are all different. And no one is right. Automotive, Industrial, and Aerospace are all different. So it's a giant mess that no one can keep track of. I spent 30 years in Aerospace, Defense, Medical, Industrial, and Automotive. Fittings are the absolute worst.

PTFE is a flouropolymer material commonly known as Teflon. -AN is a fitting interface standard that conforms to a MIL-STD (18886 I think) and there is a TON of info on line for what is -AN. a portion is pasted here:

"The U.S. Air Force, with help from Wright Patterson Air Force base, developed a fitting with 37° flare angle, before WWII, which became known as the "AN" fitting. This fitting had precision 3A/3B threads. The use of "AN" fittings proliferated from the 1930s through the 1960s to include most branches of the U.S. Military, Military Contractors, General Aviation, and Commercial Aviation. These fittings were even adopted for use in many land and sea applications of the U.S. Military as well, leading to confusion between AN and its industrial counterpart, the SAE 37° fitting. After the war, several versions of 37° flare fittings flooded the industrial market, creating a nightmare for the users. The Joint Industry Conference (JIC), an organization of manufacturers, decided to standardize on the "AN" design, except with 2A/2B thread class for ease in manufacturing. These fittings came to be known, throughout the world, as "JIC" fittings. The JIC wanted the prestige of SAE for the fitting standard. They convinced SAE to take on the task and helped in the development of the standard. Thus, the SAE standard 37° flare fitting became part of SAE J514 in 1950. The fitting became an ISO standard, ISO 8434, in 1986, replaced by ISO 8434-2 in 1996."

None of that is very interesting to anyone...unless you are actually building MIL-Spec hardware. (Which I was). But there is no such thing as -AN HOSE! Fragola sells a single 302 stainless braided jacketed nylon hose with a 500 psi working pressure that they call Fragola 840006, and it looks like SAE-100R5 to me. But the notion that there is an "AN hose" is a huge shorthand lingo that no one other than Motion Raceworks uses.

So yeah, I doubt that you have a single -AN fitting on your Bronco. If you want to check, you just need to verify the thread class on your JIC 37 degree inverted flare fitting. -2A vs -3A. And yeah...that's the only difference.

Believe me that you are not the only one to be misled by "experts" in the industry.

 

[jamesroney]

Quick question about AN fittings, making my own braided lines with AN fittings for first time. Can anyone confirm the following? To be clear I’m using AN, not PTFE… I know the difference.

You’re supposed to leave a 1/16” gap between AN fittings when you tighten the two pieces together onto the braided hose? Any risk of leaks since I tightened down flush, and then had to back off 1/16”?

Second for NPT/pipe thread ends you should use high heat thread sealant or 2-3 wraps of Teflon tape, and aim to get at least the width of the bolt into the fitting as you tighten down, usually 4-5 threads minimum.

Lastly for the flared 37 degree AN fittings, you shouldn’t use any Teflon tape or thread sealant as the angled flare is what is sealing up, not the threads. Some say add a little oil, do you just use the type of oil that will be running through lines? In this instance it’d be trans fluid, as these are my trans cooler lines.

Many thanks, just trying to do this right and avoid leaks.

OK. So what hose are you using? It's not braided stainless PTFE, so what then? And what are the fittings made out of?

Yes, some fitting manufacturers leave a gap between the compression nut to avoid over-tightening. I always thought it was a little silly. Other manufacturers specify a different fitting for different hose and bottom them. But if you are using a Parker system, they try to use the same fitting for multiple hose types. So they specify a gap depending on how fat the hose is. You need to follow the hose manufacturers instructions for their system. I usually use Aeroquip, and they tell you exactly which fitting goes with which hose. and it works pretty good.

I use Teflon tape on all tapered fittings. And no, I don't put the width of the nipple into the threaded bung. 5-6 threads is a minimum, yes. But can you imagine if you had a 2 inch nipple? You would have to thread it into the hole about 2 inches. But for smaller pipe sizes, it's not a terrible rule of thumb.

For JIC 37 degree female swivel fittings, you do not need thread sealant since it seals on the flare...yes. The people who say to add a little oil are correct. Or a high nickel or copper anti seize. Especially if you are using aluminum on aluminum, or if you are using stainless on stainless. Mild steel or zinc plated fittings do not need thread lubricant. The danger is thread galling or seizing. I would not use ATF, because I don't have ATF in my oil can. I have 10W30 in my oil can. So I would use that. But really, I prefer anti sieze.

Hope that helps.

 

[CopperBronco]

Thanks all, that’s why I put that on this forum, you all know way more, appreciate the education! Super helpful! I’m using stainless braided hoses and AN threaded fittings (w/o the olive). I got it all from Wildhorses. They didn’t specify if hose was Teflon or nylon… but did specify it was for trans cooler lines. Was good enough for me as Wildhorses is close to me and saves me a lot shipping costs. The fittings themselves are from Russell (owned by Edelbrock now).

 

[lars]

OK. So what hose are you using? It's not braided stainless PTFE, so what then? And what are the fittings made out of?

Yes, some fitting manufacturers leave a gap between the compression nut to avoid over-tightening. I always thought it was a little silly. Other manufacturers specify a different fitting for different hose and bottom them. But if you are using a Parker system, they try to use the same fitting for multiple hose types. So they specify a gap depending on how fat the hose is. You need to follow the hose manufacturers instructions for their system. I usually use Aeroquip, and they tell you exactly which fitting goes with which hose. and it works pretty good.

I use Teflon tape on all tapered fittings. And no, I don't put the width of the nipple into the threaded bung. 5-6 threads is a minimum, yes. But can you imagine if you had a 2 inch nipple? You would have to thread it into the hole about 2 inches. But for smaller pipe sizes, it's not a terrible rule of thumb.

For JIC 37 degree female swivel fittings, you do not need thread sealant since it seals on the flare...yes. The people who say to add a little oil are correct. Or a high nickel or copper anti seize. Especially if you are using aluminum on aluminum, or if you are using stainless on stainless. Mild steel or zinc plated fittings do not need thread lubricant. The danger is thread galling or seizing. I would not use ATF, because I don't have ATF in my oil can. I have 10W30 in my oil can. So I would use that. But really, I prefer anti sieze.

Hope that helps.

Beloved by aircraft mechanics everywhere, for lubing and sealing threaded fittings. A tube is a lifetime supply unless you have an insanely busy shop. I've probably used 1/10 of a tube in 15 years of trying. And have yet to find a solvent that attacks it: https://www.aircraftspruce.com/catalog/cspages/ezturnlube.php

Thanks for the great explanation of fitting standards. I use AN and JIC interchangeably because I legally can, and having had plenty of experience with JIC fittings at 5000 psi and sever shock loads I'm not too concerned about the substitution when the operating pressure is more like, oh, 40 psi.

What you mentioned about Aeroquip is only partially true. I recently made up some AC lines using their hose and fittings, which look remarkably similar to the hose and fittings they sell for other field-installable applications (stainless braid over PTFE, olive, nut, fitting with straight shank for insert into the hose, etc) but no mention of torque or bottoming of the nut. Just something like don't overtighten or you'll strip the threads. Well, duh.

 

[CopperBronco]

You guys mention the EZ turn lube, is that similar to Permatex anti-seize? I’m assuming you just use it on the threads of the AN fitting to prevent galling, correct? Does the anti-seize make it easier for fitting to vibrate loose? Hard to trust YouTube, so asking here!

 

[CopperBronco]

Beloved by aircraft mechanics everywhere, for lubing and sealing threaded fittings. A tube is a lifetime supply unless you have an insanely busy shop. I've probably used 1/10 of a tube in 15 years of trying. And have yet to find a solvent that attacks it: https://www.aircraftspruce.com/catalog/cspages/ezturnlube.php

Thanks for the great explanation of fitting standards. I use AN and JIC interchangeably because I legally can, and having had plenty of experience with JIC fittings at 5000 psi and sever shock loads I'm not too concerned about the substitution when the operating pressure is more like, oh, 40 psi.

What you mentioned about Aeroquip is only partially true. I recently made up some AC lines using their hose and fittings, which look remarkably similar to the hose and fittings they sell for other field-installable applications (stainless braid over PTFE, olive, nut, fitting with straight shank for insert into the hose, etc) but no mention of torque or bottoming of the nut. Just something like don't overtighten or you'll strip the threads. Well, duh.

I’m looking into this… the EZ turn isn’t carried anywhere locally… how much does the type of lube matter on the threads? Seems like everyone has a different opinion… Can you use Super Lube on threads to avoid galling? Or do you need something special like from Earl’s Performance, or Aeroquip? Etc… I’ll keep digging on my own, but you guys are usually faster.

 

[lars]

I’m looking into this… the EZ turn isn’t carried anywhere locally… how much does the type of lube matter on the threads? Seems like everyone has a different opinion… Can you use Super Lube on threads to avoid falling? Or do you need something special like from Earl’s Performance, or Aeroquip? Etc… I’ll keep digging on my own, but you guys are usually faster.

EZ Turn is some sort of mystery compound. It looks superficially like vaseline though much thicker, and very sticky. Not at all greasy. A primary benefit for fitting applications is that it won't dissolve in the presence of fuels. And yeah, preventing galling, especially with aluminum or stainless steel, is the point. No need to apply it (or anything else) to the beveled sealing surface of a fitting, just the threads. Don't need much. And if you apply it with a bare finger, you will be wiping a rag for awhile to get the residue off.

 

[jamesroney]

Thanks all, that’s why I put that on this forum, you all know way more, appreciate the education! Super helpful! I’m using stainless braided hoses and AN threaded fittings (w/o the olive). I got it all from Wildhorses. They didn’t specify if hose was Teflon or nylon… but did specify it was for trans cooler lines. Was good enough for me as Wildhorses is close to me and saves me a lot shipping costs. The fittings themselves are from Russell (owned by Edelbrock now).

OK, so here we go again. There is no such thing as trans cooler line hose. And there are a LOT of hoses that are capable of meeting the requirements for a transmission cooler, so there are literally hundreds of hoses that are suitable for a trans cooler. Transmission cooler lines run at nominally zero pressure. But high temperature, and petroleum resistant. So I need more info.

If you give me a Wild H part number, I can try. But EVERYBODY keeps their hose and fitting application info closely guarded as a trade secret. There is a reason for that. If you ever found out how much time and effort goes into "figuring out" a hydraulic hose, you would be shocked. But if you look closely at the Wild Horses hose kit #2053, you can see in the picture that it is SAE-100R5 hose. So it's a rubber hose with a stainless braid, and a fiber jacket. in -6 size, it has a working pressure of 2250 psi, and it bursts at 9K. It is my "go-to" hose for medium pressure hydraulic applications, because it supports re-usable ends. Super good, awesome hose that's heavy and stiff, and has no business on a general aviation aircraft, but on a dump truck, or a tractor, or an air brake line to get you past the scales...it is great. And yeah, it uses "-6 JIC 37 degree inverted flare female swivel reusable ends." And they do NOT meet -AN standards. And they are called -AN hoses by everybody that won't die if they fail. For high reliability, 5-9's, aerospace applications, we don't have a name for this kind of hose...because we NEVER use it.

And you need to stop calling the ferrule an olive. Just stop. It's a ferrule. If you live east of the Rocky Mountains, it might be an olive. If you live in the South, you might call it an olive. You might call your cousin your wife. But you live here. And here it is called a ferrule. Mostly because we have olive trees that grow actual olives in CA. So yeah. East Coast, it's Hellman's mayo, and Edy's ice cream. Out here, it's Best Foods mayo, and Dryer's ice cream.

 

[CopperBronco]

OK, so here we go again. There is no such thing as trans cooler line hose. And there are a LOT of hoses that are capable of meeting the requirements for a transmission cooler, so there are literally hundreds of hoses that are suitable for a trans cooler. Transmission cooler lines run at nominally zero pressure. But high temperature, and petroleum resistant. So I need more info.

If you give me a Wild H part number, I can try. But EVERYBODY keeps their hose and fitting application info closely guarded as a trade secret. There is a reason for that. If you ever found out how much time and effort goes into "figuring out" a hydraulic hose, you would be shocked. But if you look closely at the Wild Horses hose kit #2053, you can see in the picture that it is SAE-100R5 hose. So it's a rubber hose with a stainless braid, and a fiber jacket. in -6 size, it has a working pressure of 2250 psi, and it bursts at 9K. It is my "go-to" hose for medium pressure hydraulic applications, because it supports re-usable ends. Super good, awesome hose that's heavy and stiff, and has no business on a general aviation aircraft, but on a dump truck, or a tractor, or an air brake line to get you past the scales...it is great. And yeah, it uses "-6 JIC 37 degree inverted flare female swivel reusable ends." And they do NOT meet -AN standards. And they are called -AN hoses by everybody that won't die if they fail. For high reliability, 5-9's, aerospace applications, we don't have a name for this kind of hose...because we NEVER use it.

And you need to stop calling the ferrule an olive. Just stop. It's a ferrule. If you live east of the Rocky Mountains, it might be an olive. If you live in the South, you might call it an olive. You might call your cousin your wife. But you live here. And here it is called a ferrule. Mostly because we have olive trees that grow actual olives in CA. So yeah. East Coast, it's Hellman's mayo, and Edy's ice cream. Out here, it's Best Foods mayo, and Dryer's ice cream.

Thanks man! And apologies for the lingo, I almost called it a ferrule if it makes you feel better. I feel “olive” is weird too!

This is the part, https://www.wildhorses4x4.com/produ...raided-Hose-Kit/Bronco_Automatic_Transmission,

No info really and called and they didn’t have on file if it was rubber or Teflon hose.

 

[toddz69]

OK, so here we go again. There is no such thing as trans cooler line hose. And there are a LOT of hoses that are capable of meeting the requirements for a transmission cooler, so there are literally hundreds of hoses that are suitable for a trans cooler. Transmission cooler lines run at nominally zero pressure. But high temperature, and petroleum resistant. So I need more info.

If you give me a Wild H part number, I can try. But EVERYBODY keeps their hose and fitting application info closely guarded as a trade secret. There is a reason for that. If you ever found out how much time and effort goes into "figuring out" a hydraulic hose, you would be shocked. But if you look closely at the Wild Horses hose kit #2053, you can see in the picture that it is SAE-100R5 hose. So it's a rubber hose with a stainless braid, and a fiber jacket. in -6 size, it has a working pressure of 2250 psi, and it bursts at 9K. It is my "go-to" hose for medium pressure hydraulic applications, because it supports re-usable ends. Super good, awesome hose that's heavy and stiff, and has no business on a general aviation aircraft, but on a dump truck, or a tractor, or an air brake line to get you past the scales...it is great. And yeah, it uses "-6 JIC 37 degree inverted flare female swivel reusable ends." And they do NOT meet -AN standards. And they are called -AN hoses by everybody that won't die if they fail. For high reliability, 5-9's, aerospace applications, we don't have a name for this kind of hose...because we NEVER use it.

Regarding your first comment above - there is something at the local auto parts stores (or there used to be back in the day) that was labeled as "transmission cooler line" or words to that effect. I don't know what its composition is but it's definitely different than regular fuel line, which should NOT be used for transmission cooler line as I learned years ago when I absentmindedly used a piece of it on my truck and subsequently almost caught my truck on fire when it separated from its fitting and spewed fluid all over my headers. Rubber transmission lines stay soft and supple while fuel lines tend to get hard and rigid and slip off push-lok fittings when used w/trans fluid....

At some point after that, I switched to the stuff you reference in your WH screen shot - I had already started using it for my PS and hydroboost lines years previous to that.

Todd Z.

 

[jamesroney]

Thanks man! And apologies for the lingo, I almost called it a ferrule if it makes you feel better. I feel “olive” is weird too!

This is the part, https://www.wildhorses4x4.com/produ...raided-Hose-Kit/Bronco_Automatic_Transmission,

No info really and called and they didn’t have on file if it was rubber or Teflon hose.

Yup. That's a rubber hose. It has a braided stainless jacket. It is not a flouro-polymer hose, so it is not PTFE, and also not Teflon. Remember that Teflon is a registered trademark of DuPont, which is now owned by Chemours. So it wouldn't be Teflon, even if it were Teflon. But it isn't PTFE either.

It's rubber. And it uses re-usable hose ends. I don't even think it is even wire reinforced. But it doesn't need to be. As long as it is resistant to petroleum based fluid, and high temperature, and it is pretty...it is perfect for an automatic.

The problem comes with you call it "braided stainless hose." It is not braided stainless hose. Yes, it is braided, and yes it is stainless, and yes...there are people that will call it braided stainless hose. But it isn't. It's a rubber hose with a braided stainless jacket. Probably SAE R30 spec. Probably has a 1000 psi burst pressure. As soon as you call something "Braided Stainless" that nickname is owned by the aviation and aerospace community, and it means SAE100R14, or MIL-DTL-27267 or a bunch of other specs...but its "the good stuff" or "the expensive stuff" or "aircraft hose" and it will burst at 6000 psi, and it is impervious to almost everything, and it has no business on a passenger car, unless you like aerospace stuff on your car. It's actually not great for hydraulic service, and the stainless jacket will abrade the inner PTFE hose, and high flow high ESD fuel transfer will result in pinholes.

 

[jamesroney]

Regarding your first comment above - there is something at the local auto parts stores (or there used to be back in the day) that was labeled as "transmission cooler line" or words to that effect. I don't know what its composition is but it's definitely different than regular fuel line, which should NOT be used for transmission cooler line as I learned years ago when I absentmindedly used a piece of it on my truck and subsequently almost caught my truck on fire when it separated from its fitting and spewed fluid all over my headers. Rubber transmission lines stay soft and supple while fuel lines tend to get hard and rigid and slip off push-lok fittings when used w/trans fluid....

At some point after that, I switched to the stuff you reference in your WH screen shot - I had already started using it for my PS and hydroboost lines years previous to that.

Todd Z.

Yeah, I make fun of people that are careless with words...and I'm probably more guilty than anyone!

But yes, there is hose that is labeled "transmission cooler line" and also "power steering return" hose. But this is the paradox of industrial hose application. Hoses are not manufactured to an application! Hoses are manufactured to a specification. The the specification is applied to the application.

So if I supply or manufacture hose, and you told me you wanted a hose for your transmission cooler, I would ask you: "What hose specification do you need to meet?" And you would tell me "I need SAE J30R7 and I would go in the back and bring you a hose that meets SAEJ30R7, and everybody would be happy.

If I supply or manufacture hose, and you told me you wanted a hose for for your transmission cooler, I would ask you: "What hose specification do you need to meet?" and you would say "I don't know...I need it for my transmission." And I would say: "What is a transmission?"

So you need an interpreter to get past this. So a retailer comes in and has the universal translator and says: "power steering hose = SAE J30R7" So they put a chunk of SAE J30-R7 in a bag, and label it "power steering return hose."

Then a value added reseller determines: "hey, SAE J30R9 is much more pretty than J30R7...so I'll package up some J30R9 and people will love it." But J30R9 has a much higher operating pressure that needed. So now it becomes "power steering return hose."

(and i'm not going to even try to figure out why we are talking about a hose application when you had a fitting connection failure...but I do know what you meant...)

 

[jamesroney]

EZ Turn is some sort of mystery compound. It looks superficially like vaseline though much thicker, and very sticky. Not at all greasy. A primary benefit for fitting applications is that it won't dissolve in the presence of fuels. And yeah, preventing galling, especially with aluminum or stainless steel, is the point. No need to apply it (or anything else) to the beveled sealing surface of a fitting, just the threads. Don't need much. And if you apply it with a bare finger, you will be wiping a rag for awhile to get the residue off.

You general aviation guys are so lucky. You get to use that fancy new stuff.

I get to work with prints and specifications from the Nixon administration, and the drawings are still on Vellum. The responsible design authority has absolutely no idea what the original design intent might be, and no idea why the specification was selected. The design engineer has been dead for over 30 years, and the DCMA procurement agent does not have a shovel.

I don't get to ask for forgiveness. And I can't ask for permission. But I can build to print. And if the print doesn't call for EZ-Turn...

 

[Speedrdr]

You general aviation guys are so lucky. You get to use that fancy new stuff.

I get to work with prints and specifications from the Nixon administration, and the drawings are still on Vellum.

@jamesroney, you’re aging yourself with ^^^. I’m betting there’s a whole heap of folks on the forum that don’t have a clue who Nixon was.


Randy

 

[nvrstuk]

"I'm Not A CROOK" comes to mind... lol

James- it's all marketing. Hoses are labeled "trans hose" or "pwr strg hose" for marketing purposes- in the auto field anyway. NOT A SINGLE guy walking into Auto Zone is going to know he needs a "SP 560-39DL" hose for use in his particular application. But the marketing guys at AutoZone know that the specs on "that hose" qualify it for use in those applications.

That's why hoses in Auto stores are labeled that way- not the way you and others in the industry do.