That line is there to help keep the transmission fluid up to temperature. Note that it delivers hot coolant over the top of the transmission heat exchanger in the radiator end tank.
Thanks, Richard. That makes sense, given the proximity to the input/output of the transmission cooler lines, but I am not familiar with the internal layout of the radiator.
I'll take some more pictures/video tonight that shows the complete routing of the system. I'm not sure which of the bypass lines is the output and which is the input from/to the engine. I believe one line terminates in the intake manifold near the thermostat housing, and the other terminates in the water pump itself. I'm guessing the output is from the manifold, not the pump.
Steve
