How to Determine Which Transmission Line is the Return Line for Installing a Transmission Cooler

Published 09/03/2014

Question:

need to knw which side is the pressure side to hook up transmission cooler on 2001 dodge ram ext cab 2 wheel automatic 1500 5.9

asked by: Sandy D

Expert Reply:

The method we use to determine the correct line to install a transmission cooler on is pretty simple. You want to install the cooler on the return line.

To determine which line is the return line you will want to start with your truck totally cooled off. Start the truck and put it in drive, apply the brakes firmly and then apply the accelerator slightly so that the rpms climb. Put the truck back in park and shut it off.

Now go out and feel the two lines leaving the radiator. The cooler of the two lines is the return line and the one to install the transmission cooler on.

expert reply by: Jameson C