ATF cooler for 04 RL
 

I would like to install aftermarket kit and connect into return hose from radiator to AT. So the question is which atf hose is returning from radiator?
https://cimg3.ibsrv.net/gimg/acurazi...17d1652fab.jpg

That is a good question.
Do you think a cooler is necessary? Do you have any temperature info from the fluid? I think these transmissions are pretty solid.

If your place is to bypass the radiator altogether, why not just plug the lines and connect it in-line? why bother going through the radiator AND the ATF cooler?

i think the best option is instaling cooler after radiator. I have Accord V6 and atv cooler is installed like that. I use my Acura in European Highways driving fast so i would like to avaif problems with gearbox.

Right. And the rpm's are relatively high with only 4-speeds.

My guess would be hose # 15 for the return from rad, right next to bottom rad hose connection to water pump inlet.

you're right, hose 15 is return for atf from radiator.
ATF cooler is installed.
https://cimg3.ibsrv.net/gimg/acurazi...9805b1d5ab.jpg
https://cimg4.ibsrv.net/gimg/acurazi...b951216509.jpg

Nice job.

How's the AT temps with the new cooler? Did you notice a substantial drop between stock and the new aftermarket cooler?

my Acura is in parts now because i'm doing renovation so i can't test it. but I think i wont measure temp because it required new gauge.
https://cimg5.ibsrv.net/gimg/acurazi...35d944a6b8.jpg