I want to replace some of the trans fluid in my '04 van without dropping the pan but can't remember which line is the return line from the radiator. How can I identify the correct line?

 

Hi , I would think" the top trans fluid line " on the radiator would be the return line because of air or bubbles . Remove the fluid with an empty gallon jug to gauge the how much you take out .Loosen the line an have the wife ready to stop the engine just before it gets about 3 quarts to prevent spills . Refill the same amount of fluid with the engine running . My thoughts Lovvorn , Dodge Caravan S. E. Born June 2010 # 648057

 

you could try and suck the fluid out of the fill tube with a oil extractor if you don't want to change the filter, do it a few times every 100miles or so and you will get a high % of new fluid int

 

Got the job done and found out which line is the return. It is the one closest to the engine on the transmission. I removed the line and put a length of hose on the barbs and placed the end of both hoses in a bottle. This way I was sure to catch the fluid regardless of which line was the return line.