View Full Version : aftermarket trans cooler install

07-21-2012, 04:04 AM
I have a trans cooler and it is all mounted in. only problem i have right now is I dont know which line is the return line. I have an 09 unlimited. Any help with this would be greatly appreciated!

07-21-2012, 05:53 AM
I did this to my '09. Only problem is I sold it last week so I can't go take pics for you. Go look at the write ups on JK-Forum. I remember finding pics which made it clear which lines were which.

07-21-2012, 07:12 AM
Here is the same link to the thread I posted to answer your original "hot oil light " question, read through the very 1st post in the write up from the JK Forum and look at the photos provided. Hundreds of people, if not more, have followed it with successful results each time.


07-21-2012, 02:30 PM
Thank you and although I have looked at this very closely this thread does not tell me which line is the return line, just the line they used. If I send it through the cooler and then the AC unit I am heating the oil back up so the cooler is not as useful as sending it through the AC unit and then the cooler. This will give me the best results. The top line is normally the return line but not in all vehicles. I guess now the dealership is open Ill give them a call and ask service. I'll post my findings here when I finish with pictures of how I did mine. Thank you for all your help!

07-21-2012, 02:47 PM
Did this mod on my 07 unlimited about a month and 1/2 ago. The top line should be return and the one you want to cut into. You can check by turning jeep on, run for about one minute and touch the lines. The cooler to touch line will be the return line. Best of luck. It's a pretty easy install if you don't have a big ol winch already installed like I do.

07-21-2012, 08:22 PM
I was able to figure it out. Jeep does it a little backwards. The top line going into the AC condenser is the return line. This is the line I spliced into to ensure it is cooled after being cooled if that makes sense.Thank you for everyone help and hopefully this will help others in the future!