i am installing a transmission cooler and don't know which line is which. i noticed on the transmission one was located higher up. it is a 2003,4.7 liter engine
which transmission line is the return and which is th inlet on 2003 Dodge Durango
If you put both hoses into a oil container or drain pan, get a friend to start the truck and run for a few seconds, the line bringing oil from the transmission to the cooler will spit out oil, the return line will not!