Thread: Trans Cooler Line Help

Originally Posted by robrileyw

Just so everyone knows the shift kit installation went pretty smooth, I took my time and cleaned everything up, swapped the springs according to the Transgo shift kit instructions, and a few hours later i had the pan bolted back up ready to go. I then had to replace the supply line to the bottom of the radiator since it started seeping as a result of the P1811 max line pressure command...After struggling using a 3/8" transmission line disconnect tool and spending about a half hour too long not being successful with this disconnect tool, I used a tiny flathead and hammer and popped the clips out in a few mins. After about 5 hours total of installing the shift kit, the supply line, and running back and forth to the parts store...I decided to hold off installing the transmission cooler for the time being.

I had removed the plastic grill pieces that run along the hood latch area, both the headlights, taking measurements, trying to figure out where to route the transmission cooler lines....it was just too much of a project to tackle for the day. I'd like to hear from others that have installed the transmission coolers on Grand Prix's, how you guys routed the transmission cooler lines? My transmission cooler lines said not to have less than a 3" bend when routing the lines, one of the few possibilities of routing the trans lines was a small hole behind the passenger side head light...the battery sat right there past the hole along with the top radiator fitting pretty close....on top of all this there was a vertical bar running from the top of the hood latch assembly down to the bottom of the ac condenser which prevented me from mounting the Imperial High Performance Trans Cooler without modifying this vertical bar....

Like I said before I live in upstate NY which gets pretty cold in the winter, anyone that has installed a transmission cooler in these Grand Prix's, let me know how you guys routed the cooler lines..

Thanks!

Rob,

I installed an in-series cooler last fall and will describe my approach. I also spent way more time planning/measuring than it actually took to install the cooler. I mounted my cooler on the driver's side of the car and routed the lines around the driver's side of the ac condenser/radiator (I use these terms interchangeably which is probably wrong).

First, here is a sketch I made of my setup on a 2008 base 3.8L. The perspective is drawn from the front if you were standing slightly towards the drivers side:


EDIT: THE LINES SHOWN ABOVE ARE INCORRECT - THE ENDS ARE LABELED CORRECTLY BUT HOW THEY CONNECT TO THE RADIATOR ARE FLIP FLOPPED. THE TOP LINE FROM THE STOCK RADIATOR IS THE RETURN LINE AND SHOULD BE TAPPED INTO.

If I remember correctly, the transmission lines connecting were metal on the ends connecting to the transmission and radiator with a segment in the middle that was the same rubber tubing as was provided in my cooler kit. This is where I tapped in. I located my cooler as directly behind the drivers side grill opening as I could. I figured this would provide the most airflow vs behind the bumper or other obstruction. I think I took a different approach to routing my lines than others but it was very clean and has worked great so far. I was able to route my lines immediately outside of the AC condenser/radiator. There was a plastic guard or brace (might be the "vertical brace" you were referring to) just outside the radiator but I was able to route my lines BETWEEN the two without kinking or breaking the 3" bend rule. Note that I actually DID route the lines high to low as they wrapped around the radiator, this softened the curve in the lines. If I were to wrap them around the condenser on a level plane I think the bends would have been too sharp. If your car has the same setup as the 2008 model you should see this once you start digging in. My lines came out at the same location where the rubber portion of the original transmission lines were located so it was easy to tap into once I got them routed through the gap.

I had to take of the big plastic bottom guard which was somewhat challenging at times. Other than that I don't think I disassembled anything else.

Let me know if you'd like more information or want pictures of my setup.