I'm looking to buy the tru-cool max 4739 from dieselsite and not sure if I should go with a bypass or not. It is my understanding that the stock cooler has one, but with living in cincy it gets real cold in winter and takes a while for trans to warm up, so I don't want to over-cool things in the winter, causing a problem. Now in the summer I am pulling 20ft. enclosed trailer around city so I need good cooling. Are there any reasons not to get the tru-cool with a bypass and use it in line with the stock bypass cooler to stay warm in winter and cool in summer?? That's my thinking. Any advice/ comments-Thanks!

 

Get one without the bypass as you do already have one. Install it so it runs in series with the factory cooler. Transmission -> factory cooler -> TruCool -> Transmission.

 

Right on the money as usual!! This way, none of the tranny fluid will see a cooler until it's warmed up.

Also, here's some good info about the Tru Cool Max taken from DieselSite: "Tru-Cool" self regulating coolers - Thick or thin, it's the oil that regulates the cooler. That's the principle behind the revolutionary new TRU-COOL SR series of self regulating transmission oil coolers. Thicker oil that is below the ideal operating temperature by-passes the cooler through the upper two plates. When the temperature rises, it becomes thin enough to pass through the entire cooler and receive TRU-COOL's superior heat transfer efficiency. Automatically.

 

Quick question, the 7.3 specific instruction I got with the tru-cool look like you tap into the return line from the transmission at the rubber hose. Would that put tru-cool before the factory cooler? Thanks.

 

There are two rubber hoses at that point, you could do either one. Most everyone has it plumbed similar to this

The red is return to the transimission. The black goes to stock cooler, then to trucool, then back to hard return line through red. I have more pics in my gallery as well.

 

I had to go crawl out in the snow and double check the lines because I couldn't remember exactly how I hooked it up but I think cangim may have gotten it backwards, correct me if I am wrong. The transmission line going to the factory cooler that is closest to the ground goes to the back of the transmission which is the return line, the line comming from the front of the transmission is the pressure side. My pressure side has a factory crimped hose attached and I did not touch that one. The return line had one of the cheap Ford band clamps that I removed and tossed. I also had to purchase additional 3/8" transmission line since the kit did not come with enough to run both lines to where I wanted to mount the cooler.
I disconnected the hose from the return line and repaced the hose from the factory cooler and ran it up to the TruCool, then from the TruCool, I ran another hose back to the transmission return line. I covered both new lines with plastic loom to prevent them from chaffing on the side of the radiator.

HERE is a shot of the transmission line hookup.
HERE is a shot of where I mounted the cooler although it's a little difficult to see through the cattle guard I have mounted on the front.

 

Thanks a bunch for checking that out! I'm going to look at my truck later and see if I can figure it out. Thanks again.

 

Thanks for the help! So if I understand this..if I install the tru-cool w/o bypass after my factory cooler, none of the fluid will reach the tru-cool untill warm enough and/or if it does reach the tru-cool and is not warm enough it will only pass through the upper portion of the cooler before returning to the tranny? Thanks again for the help!

 

You are correct. That's how the fluid would flow.

 

I probably got them mixed up when I actually hooked mine up. What you want for sure is to tie your cooler in between the stock and the stock return line. It is the line at the back of the transmission. It is also a little lower to the ground. Now I have to actually check mine out and see what line I tied into...

 

it looks like you tied into the inlet which wouldnt make a difference except it will go to the tru-cool first then to the stock cooler

 

Thats what I did, I will change it when I pull the tranny out for a rebuild.