I am changing transmission fluid and filter while changing my timing belt and water pump. I wanted to do the more complete flush of the transmission fluid as outlined in the "How-To" write-up. I am unsure which one of the transmission lines is my return line. As I lie under the car and look up at the bottom of the radiator both lines connect to the bottom of the radiator, one on the right and one on the left instead of one on the top and one on the bottom as suggested in the write-up. The Haynes manual doesn't say anything about the transmission cooler or its lines, that I can find. If I have to guess, I'm going to start with the Left one and see if it is the return no particular reason just "gut feeling". I was hoping that someone knows for sure so I didn't have to guess. Thanks.

Thanks, but finished it yesterday. Found out by trial and error which one it was. Unfortunately, according to what I measured I probably left about a quart of old fluid in it, hence the error part  , but it has to be much better than what it was. The old fluid was pretty dark and burnt smelling. We haven't owned the car very long and I have no idea if it was ever changed before or what fluid was used.