Transmission cooler lines fitting sizes

hear

hear

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Can anyone help me understand these fittings, what type they are etc?

One fitting threads on both ends. The side that goes into the trans appears to be flared and threads into the 3/8” flare size on the wall at Home Depot.

The other side of that fitting threads into the 1/4” “brass pipe fitting” on the wall at Home Depot.

C389F622-EE14-4B2D-B4AF-108F82AF5F2F.jpeg


The other fitting has the quick connect on one side and the other side also fits into the 1/4” brass pipe fitting at Home Depot.

E172930C-AB3C-4AE9-BD2B-2D1129C7AF0E.jpeg

The flare is obviously a flare fitting (is that the same as AN?), but what are the other ones? Are they NPT? Or something else?

Educate me, please.
 
also, those are the fingernails of a dude who has been working on his car without gloves. Judge not lest ye be judged yourself.
 
LONGJP2 said:
Maybe shop for fittings at an Auto parts store instead of Home Depot?
Click to expand...

At my auto parts store they don't have a wall of fittings that I can thread into to see what size fits. I'm happy to drive to your store where they have that. The stores near me don't even carry such fittings as far as I have ever seen. So I went to a store that did.


But if you didn't know the answer you could've just said so. But I guess you kindof did say so.
 
I get that they have a nice selection for comparison.
What I meant was maybe an old school auto parts store might have someone that knows more than a Home Depot guy. :)
 
hear said:
Can anyone help me understand these fittings, what type they are etc?

One fitting threads on both ends. The side that goes into the trans appears to be flared and threads into the 3/8” flare size on the wall at Home Depot.

The other side of that fitting threads into the 1/4” “brass pipe fitting” on the wall at Home Depot.

View attachment 339864

The other fitting has the quick connect on one side and the other side also fits into the 1/4” brass pipe fitting at Home Depot.

View attachment 339866
The flare is obviously a flare fitting (is that the same as AN?), but what are the other ones? Are they NPT? Or something else?

Educate me, please.
Click to expand...

The top picture is a 3/8" flare x 1/4" MNPT. Compared to AN, the angles are both 37 degrees but the flare threads are slightly different. The AN fittings use a 3A thread class and the SAE flare uses the 2A thread class.

Unified threads come in three different classes:

1A (external) & 1B (internal): for applications where a liberal tolerance is required to permit easy assembly even with slightly nicked threads.
2A (external) & 2B (internal): most commonly used class for general applications.
3A (external) & 3B (internal): for applications where closeness of fit and/or accuracy of thread elements are important.

Here's an article that goes into the history and explains the AN and flare differences:
https://www.mfcp.com/our-blog/an-jic-37-flare-fittings


The pipe threads on the other fittings are NPT (National Pipe Tapered).
 
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LONGJP2 said:
Any idea why 1/8" zerk uses NPT (1/8 - 27), but a 1/4" zerk uses UNF (1/4 - 28)?
Just curious.
Things that keep me up at night. :unsure:
Click to expand...

Unfortunately you're still going to stay up at night because I don't have an answer for you. It's probably somebody yanking our chain and laughing their ass off when they picked so many different types and sizes.
 
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