OK, I'm getting confused. I keep hearing, use the aux. cooler in the radiator. Then I hear bypass it. I guess I would like to hear some more opinions. BTW my stall is a 3500 2.5 STR. So cooling is very important to me.
Thanks,
Philip S.

 

Use it. It's additional cooling and has worked for decades.

 

I agree...my opinion is to use the factory cooler with an auxilary cooler plumbed in series with the return (upper) line. This is how I've done it on all of my vehicles in the past...easy, cheap, and effective

There are different methods I'm sure (such as littreddevil mentioned, completely bypassing the factory cooler), but to the best of my knowledge, adding an auxilary cooler is the most common.

 

Okay, I'm gonna show my ignorance here because I have a transmission cooler that I want to install, but there's one problem: how do you distinguish the transmission oil cooler lines from the engine oil cooler lines?

On my '00 Sierra 4WD, there are lines at the top and bottom on the left (passenger) side that I figure are the engine oil cooler lines. In front of the radiator is another cooler with lines going to the AC condensor (I think) and on the right (driver's) side of the A-frame is a tall and narrow stacked plate cooler. Don't know exactly where the lines run from that cooler. It's about 16" high and less than 3" wide. What is that for, do you think?

 

The lines on the passenger's side are the trans cooler lines, you can visually follow them back to the trans. The item in front of the radiator is the a/c condenser, and the vertical cooler on the driver's side is for the power steering. If your vehicle has an oil cooler, those lines will be on the driver's side radiator end tank.

 

Thanks, Bud! Man, I was all crossed-up, huh? I thought the lines from the tall, narrow cooler were going to the power-steering but I never knew the PS needed cooling. Live and learn, huh? Thanks again!