2009 AT cooler leaking?

Hey guys,
I noticed some leakage under the truck the other day and traced it to the upper AT cooler hose. In all my searching I've only found one other similar issue, but almost of what I'm finding is relating to an actual "radiator style" AT cooler. My first assumption was that tranny fluid was leaking from that hose, simply because it's attached to the transmission, but I'm realizing that I didn't get a positive ID on the fluid. I'm just looking for clarification that this is indeed a part that flows coolant and not AT fluid (it's definitely coming from the end of the house not the gasket where it attached to the trans), and furthermore I'm curious as to whether you all think it's probably just the line or if that might be indicative of a part failure? If it is the part how much of a PITA is the replacement and will I be dealing with anything other than coolant? Thanks in advance!

 

I believe that puck is the ATF heater. It would have both coolant and ATF running into/out of it.

Hopefully it is not a case where the transmission fluid is being contaminated with antifreeze

 

Thankfully I've discovered it is just a coolant leak, it's leaking from one of the hoses coming in or out and I was confused because I'm still used to thinking coolant is green. I'm guessing this cooler / warmer part probably doesn't have any moving parts within it so much as it's just an inlet and outlet, so any leaking should just be caused by an old hose. I think I'm just going to stick an old fashioned hose clamp on there instead of the pinch clamp style until that hose comes in. If anyone else has any input on whether I should be worried about this ATF cooler part otherwise, please let me know.

 

An external leak is much preferred to an internal leak. And I think you are correct that an internal leak of the heater puck would be pretty rare.

Sounds like you have identified the culprit and are correcting the fault, so I think you are on the right track.

I imagine there would be some weird transmission operation if contamination were an issue, but you could always do a drain and fill of the trans to confirm.

 

Turns out it is just a coolant line, as the trans fluid stays inside the tranny. Only problem now is I can't find the part number for that little length of hose for the life of me. Any thoughts here? I found this diagram but the part numbers seem bunk. The lower hose is the one I need. Thanks in advance.