How To Tell Which Transmission Line Is the Return Line On 2005 GMC Canyon

Question:

Both transmission lines are on the bottom. How do I know which one is the return line. I have a 2005 gmc canyon

asked by: Jerry

Expert Reply:

There is a quick and easy way to find out which line is the return line. You want to do this when the engine is cold. Raise the hood on your vehicle. Start the engine and put it in drive while you have your foot on the brake. Let it run for about 10 or 15 seconds and then turn the engine off.

You want to then quickly feel the two lines. The cooler of the two lines is your return line and that is the one to use for a supplemental cooler like part # D13503. If you go with the # D13503 cooler you will also need the # D13035 hose fitting.

I have attached a link to a helpful article about transmission coolers you can check out.

expert reply by: Jeffrey L