Originally Posted by miketexas
Both sides will have hot fluid flowing through them especially after the trans warms up. You probably mean you want to use the return line to connect to your cooler. Using the Return line means that the fluid going to your cooler has already passed through the radiator. I have never checked but I have been told the return line is on the driver side of the radiator.
Thats what I'm seeing. Yes the return.
Because, when I flushed it, I took off the one on the right/pass side and pumped out the transmission.