I'm installing a cooler on my 700R4, but I don't know which line is the return line. Lines are off right now. Tranny top or bottom, and radiator top or bottom?

 

Bottom line from transmission to cooler, top line from cooler to transmission.

 

I'm going to series it with the radiator and I want the cooler last in line so I need to know which fitting on the tranny is the return.
Thanks

 

I believe the return line is the upper line, both on the trans and on the radiator.

 

Read that as "Bottom line from transmission to factory cooler in the radiator, top line from factory cooler in the radiator to transmission."

 

Yup. that's how I did mine and haven't had issue yet.

I've heard that depending on driving style and climate it might be benificial to put the aux cooler on the pressure line instead of the return. Have you heard anything about that before?

 

Yes, but it appears to work for people either way. I almost don't think there's a "wrong" way to do it.