Which is Transmission Fluid Return Line on Radiator of 2000 Chevy Silverado

Question:

Folks: I have A Derale cooler ready to install on my 2000 Chevy Silverado 4.8 liter. I want to hook it to the return line as suggested. On this truck, is the return line the UPPER line on the radiator or the LOWER line? Thank you.

asked by: Gary W

Expert Reply:

On your radiator the top port on the radiator is the inlet and the bottom is outlet. Here's a fool proof way to check and be sure though.

In order to tell which transmission fluid line is the return line leaving the factory cooler of a vehicle like your 2000 Chevy Silverado you want to start with your vehicle cold. Start it up and put it in drive and brake torque it (apply brakes and rev the engine), for about 10 seconds or so, put vehicle back in park, and turn engine off.

Now quickly go out and feel both transmission lines. The cooler of the two is the return line and the one to use for installing the # D13035.

expert reply by: Jameson C