AN fittings

[Tony]

Ive got a few AN fittings in my oil system that are refusing to seal properly.

I know its uncommon with AN but should I try some thread tape and pipe dope on them?

 

[Chris]

No. You have a problem somewhere. Either a mismatch or a flaw or damage on the sealing surface. Sealer will fail at the worst possible time.

 

[Whoz Your Daddy]

I just got my oil cooler back from having it hot tanked and what ever they used it messed up my fitting on the ends? had to replace them to get them to stop leaking

 

[MOBILEMERCMAN]

Both sides of the connection needs to be the same fitting type. JIC has the highest pressure rating , you will find them on steering. Most adapters are marked, but you can compare visually the seat angles.

Like Chris mentioned there cannot be a scratch on the seal surface. If you look carefully you will see the a print on the adapter side of the match up. On a worn fitting there maybe a groove. Any flaw means it is NFG. Check both sides carefully

 

[Nordicflame]

AN and JIC are both 37* flare and are interchangable.
AN (Air Force / Navy) are just held to tighter tolerances.
SAE is 45*
Dave

 

[Chris]

The actual difference between JIC and AN is aviation certification. In fact, AN doesn't technically exist as a atandard anymore. You have JIC and aviation-certified JIC, although indistry still hangs on to the AN nomenclature.

We do tons with JIC in fluid power applications. I have deliberately tried to break JIC fittings by over-tightening and with even a long wrench of the correct size, I've never been able to. Now that's plated steel, no S/S or aluminum. But the short of it is, they'll take more tightening force than you'd imagine. And often you need it to get them to seal. In an engine oil application, I can't imagine the pressure being that high, which is why I suspect damage to a fitting. I would also look to see if the nut is bottoming before the flare makes contact- between-brand mismatch isn't unheard of. Also, I seem to remember some problems we had a few years ago with some imported machinery and British (BSBP) threads fitting but not sealing. Faint recollection and a long-shot but I never rule anything out.

 

[Chris]

There are 3 flare seat angles I am aware of: SAE is a 45, JIC is like 30 and AN is arc of sorts.

I think youre thinking of the euro-automotive bubble-end flare they do on lines. I know they exist but know nothing of the standard. I do know they're semi-compatible and will screw together with some domestic stuff, but won't seal.

 

[Strip Poker 388]

The Earls style an fitting ,the aluminum seat will split from over tightening them.

Also on my oil line going into the adapter, the fitting on the adapter is steel and line is aluminum and it leaves a indication in the steel fitting.




so a 45 seat with seal up to a 37?

 

[smittyseng]

I would also have to say one of your fittings it either damaged ( do a close visual) or if its a swivel fitting that has a o-ring in the swivel it needs to be replaced,Smitty

 

[nthdegree]

The Earls style an fitting ,the aluminum seat will split from over tightening them.

Also on my oil line going into the adapter, the fitting on the adapter is steel and line is aluminum and it leaves a indication in the steel fitting.




so a 45 seat with seal up to a 37?

Not at higher pressures...this is not the design intent...

 

[Strip Poker 388]

I would also have to say one of your fittings it either damaged ( do a close visual) or if its a swivel fitting that has a o-ring in the swivel it needs to be replaced,Smitty

How do you replace the oring in a swivel seal? mine are brazed together.

Also the Areoquip fitting in pick were the corrosion is,is the brazed part,it doesn't hold up in water for long,I found about 2 years =100hours,thats not much salt water,Earls is the same,The Earls tech at PRI 07 said the black ones are a harder anodizing would hold up longer but still corode.http://www.circletrack.com/enginetech/ctrp_0411_earls_ano_tuff_fittings/index.html

 

[MOBILEMERCMAN]

Aluminum fittings for salt water is a bad choice IMO

 

[smittyseng]

How do you replace the oring in a swivel seal? mine are brazed together.

Also the Areoquip fitting in pick were the corrosion is,is the brazed part,it doesn't hold up in water for long,I found about 2 years =100hours,thats not much salt water,Earls is the same,The Earls tech at PRI 07 said the black ones are a harder anodizing would hold up longer but still corode.http://www.circletrack.com/enginetech/ctrp_0411_earls_ano_tuff_fittings/index.html

you replace the fitting

 

[Strip Poker 388]

you replace the fitting

thats what i thought