Trans cooler line leak help.

[1998_K1500_Sub]

Dorman 800-755

Better pictures are available here:

Dorman Products - 800-755

Transmission Line Connector

www.dormanproducts.com

OK, so that's NOT a flare fitting into the radiator. If it's leaking there, you could try the Permatex product... but it looks like Dorman has already applied some sort of sealant / thread locker on the fitting already...

The female portion is obviously for a flared tube end. You should not apply sealant there.

 

[1998_K1500_Sub]

One torque spec I found for the nut on the transmission's oil cooler pipe was given in the 4L80E section of the 1998 GMT400 service manual. There, they say 20'#.

Click on this image to expand it for detail, look for "Transmission Oil Cooler Line to Radiator Nut"

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Here's another one, from the 700R4 section of the 1989 GMT400 manual, which says 21'# for the line to the transmission and 27'# for the line to the radiator.

I'm not sure I would be comfortable putting 27'# on that fitting. Using a backup wrench on that Dorman part, and applying 27'# to the nut on the transmission tube... well, I might try it. I would try 20'# first and if it didn't leak, then "done". If not, then maybe squeeze it tighter, but use 27'# as a maximum.

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[Archaic2021]

I will definatly try the loosen and retighten and see what happens.

Yeah its not leaking at radiator its coming out of where the factory lines threads into the female side of the adapter

 

[Schurkey]

its not leaking at radiator its coming out of where the factory lines threads into the female side of the adapter

Take it apart, take a photo of the tube end (likely flared) and the adapter interior (might be inverted-flare, might be some other sealing method.)

IF both are intended to seal on the flare, you can go crazy tightening/loosening to see if that helps. If the tube end and fitting are just not compatible, you'll need to make other corrections.

 

[east302]

While you’re messing with this, you should replace that rubber cap above the transmission lines. It’ll start cracking in a few months. There are threads on a fix, usually using a piece of heat-resistant silicone hose or cap.

The GM radiators are still available and don’t require you to fix them to make it work. Check Rockauto, but they’re often cheaper shipped through Amazon.

 

[Archaic2021]

So i tries the new dorman fitting...worked perfect...but..i should have got to.

The bottom connectir is leaking. I guess i didnt notice since the top was streaming fluid onto the bottom.

I didnt get a picture but the inaide was definetly different. Qhen i compared it felt like the line seated more properly onto the dorman fitting.


Hopefully i can pick up another tomorrow and then be good.

 

[Archaic2021]

Update if anyone else has this issue. New dorman adapter fixed issues...i feel like i hate tighten and re tighten a few times but no leaks..all good