WTB Trans Cooler Line Fittings, 1st gen

Well just my luck, I broke both fittings in the transmission case.

Looking for two of the cooler line fittings that fit the earlier cummins trucks. 90 model 727 automatic transmission, brass fittings that screw into the case, then the cooler lines screw into these.. please let me know what you have as I have had no luck finding these fittings locally, and the salvage yard I used to use shut down... thanks!

An alternative could be NPT to AN fittings at the transmission. Then a short braided steel line to a swagelok fitting and connect to your hard line. Short braided steel line would need with AN fitting on one end, NPT on the other.

This would require cutting your steel lines back.

Ok thanks for the info!
There’s not a whole lot of pressure running through the cooler lines, correct? Curious if I can use a hydraulic hose and clamps to keep it on the cut steel lines?

I did find Dorman fittings, but when I ordered one and tried it in the transmission case, it screwed in a little ways then bottomed out about a 1/4 inch away from flush against the case.
I called a dealership I use when I can’t find parts locally and he gave me the Chrysler part number for these. I crossed them over to the local parts store (oreillys and Napa) they both came back with the same Dorman part number I tried before. Am I wrong thinking the screw in fitting is supposed to fit flush against the case when tightened? Or is it supposed to stick out a little bit from the case?

weazel said:

Ok thanks for the info!
There’s not a whole lot of pressure running through the cooler lines, correct? Curious if I can use a hydraulic hose and clamps to keep it on the cut steel lines?

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In a pinch, I’ve had to cut through my steel lines to replace a cracked section with a piece of hose. Did it without a flaring tool or anything.
So yes, in my experience just about anything will work.

The reason your fitting didn’t bottom out is because the port in your trans case is 1/4” NPT. It should thread in 1/2 - 2/3 of the way in. Sounds like you have the correct Dorman fittings.

Red Sleeper said:

The reason your fitting didn’t bottom out is because the port in your trans case is 1/4” NPT. It should thread in 1/2 - 2/3 of the way in. Sounds like you have the correct Dorman fittings.

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Ok, thanks for the info! Don’t know much at all about the old transmissions so this threw me for a loop. I’ll grab a pair of the Dorman fittings and go from there. Thanks for the help guys!