Added Tru-Cool Tranny Cooler, Coolant or Tranny Fluid

[Scraps66]

I have a 2011 Yukon SLE. No towing package so no tranny cooler so I've added the Tru-Cool. I have it mounted and buttoned up, only thing left to do is to tap into the return line to the tranny. I'm piping the cooler in series with the radiator.

From all my research, a lot of guys talk about cooling the tranny fluid, and after installation checking the tranny fluid level. I've only had this vehicle for a year so not intimately familiar with a lot of things, but, for this vehicle, there is no "transmission oil cooler." The "transmission lines," metal lines going from the tranny to the radiator, entering on the bottom, returning from the top of the radaitor, flows coolant from the radiator to the tranny, and cools the tranny fluid that is in the trans. There is no dedicated cooler for the tranny fluid itself. Am I correct?

When I crack that top metal fitting on the radiator, the return line for the transmission, it's just coolant coming out. All of my research was from 07 and back, didn't find a lot on 07+ Yukons.

Just want to make sure I'm getting the max benefiits. I can see cooling the trans fluid directly woudl be best, but what I'm doing is simply increasing the capacity of the radiator by adding the Tru-Cool and more Dex-cool coolant. Not cooling the trans fluid alone.

Just looking for someone to set me straight. Killing me that I can't finish cuzz I don't have the right fitting the tap into that spring laoded fitting on the top.

 

[Scraps66]

2011 SLE, Added Tru-Cool, is it coolant or Tranny fluid?

I have a 2011 Yukon SLE. No towing package so no tranny cooler so I've added the Tru-Cool. I have it mounted and buttoned up, only thing left to do is to tap into the return line to the tranny. I'm piping the cooler in series with the radiator.

From all my research, a lot of guys talk about cooling the tranny fluid, and after installation checking the tranny fluid level. I've only had this vehicle for a year so not intimately familiar with a lot of things, but, for this vehicle, there is no "transmission oil cooler." The "transmission lines," metal lines going from the tranny to the radiator, entering on the bottom, returning from the top of the radaitor, flows coolant from the radiator to the tranny, and cools the tranny fluid that is in the trans. There is no dedicated cooler for the tranny fluid itself. Am I correct?

When I crack that top metal fitting on the radiator, the return line for the transmission, it's just coolant coming out. All of my research was from 07 and back, didn't find a lot on 07+ Yukons.

Just want to make sure I'm getting the max benefiits. I can see cooling the trans fluid directly woudl be best, but what I'm doing is simply increasing the capacity of the radiator by adding the Tru-Cool and more Dex-cool coolant. Not cooling the trans fluid alone.

Just looking for someone to set me straight.

 

[TowGMC]

Can't directly speak for the '11 with no tow package, but every GM vehicle I've owned worked this way....

The hard lines plumb trans fluid through a separate core section in the radiator, so the only fluid in those lines is trans fluid, not antifreeze. The trans pump moves trans fluid to the radiator and back again, effectively reducing the oil temp in the transmission. The engine's cooling system is designed to keep the coolant at about 210 degrees or less. So if the trans oil temp starts to climb then the fluid circulated to the Yukon's radiator uses the cooling capability of the radiator and antifreeze to lower the temp of the transmissions oil. Yes, they are two separate chambers in the radiator, but since antifreeze is a much better coolant than oil, the radiator takes some of the heat from the trans lines and essentially lets the coolant help cool the trans fluid.

By adding an external trans cooler in line with the radiator you are adding an extra margin of cooling capability, as well as capacity. So you'll need to add additional trans fluid to the transmission, roughly equivalent to the capacity of the new cooler and lines. Best way to do this is to get the truck up to operating temp and while it's running pull out the trans dipstick and check the level. Top it up accordingly. Then drive it until the trans is up to operating temp, pull the stick (again, truck running) and check the level again. Only thing I'm not certain about is whether the truck needs to be in Park or in a gear to check the trans temp. Just don't recall. But I suspect the cooler and lines only add about 1/4 to 1/2 a quart of trans fluid at most. Don't overfill. it's easier to add a bit than it is to remove if overfilled.

 

[Scraps66]

Thanks Tow, Iunderstand everything you're saying.

Do you happen to know where those tranny fluid lines run tot he radiator? The lines on the passenger side, metal lines top and bottom, those are coolant lines I'm positive. I looked closer again, and I think the fluid lines run along the side rails and under the rock shield below the radiator. I just never looked closer. All the research I had done showed guys tapping into the radiator lines - not what I want to do cuzz it won't provide as much cooling as running the oil through a separate cooler and the additional amont of fluid will make for more cooling too.

 

[jcrack_corn]

if there is antifreeze in those lines then you have bigger problems than figuring out how to install the cooler.

coolant and trans fluid on these cars can look the same, and trans oil is very thin.

engine coolant has nothing to do with transmission cooling....the lines are run up there (as mentioned above) just to make use of a separate core in the radiator for cooling because its convenient and in the wind path....

(coolant in fact is much hotter than you would generally want your tranny to operate at)...ie an engine is happy at 200 degrees...tranny not so much.

maybe this can help you:
http://www.youtube.com/watch?v=0mnDxrtV3Xk

 

[Pooter]

The two hardlines on the passenger side of the radiator are for the transmission fluid. Unless you have the heavy duty towing package, you wont have the additional aux cooler that sits in front of the radiator/condenser under the hood latch in the core support.

The fitting should be leaking trans fluid, might be the same color as the coolant, but its trans fluid. I just hooked mine up this past weekend, I used the derale fitting to hook up at the radiator(top return) then slipped the return hose for the tru cool over the stock return hardline. There should be no mixing of coolant/trans fluid.

 

[Scraps66]

No, not in the lines. Found out what my issue was. Didn't realize the trans cooler is submerged in the radiator. If you take off the trans hardline connector - unthread not unclip, coolant will come out of the opening. That's why the fitting has that big bezel washer on it and an o-ring to seal the coolant off. So i was seeing coolant, but not from the trans line. Very little ATF came out, lots of coolant though. Imadumfuk.

Just waiting for the fancy spring clip adapter to tap into the trans retrun line.

 

[Scraps66]

Unclip the hardline, don't unscrew it from the radiator. With the connector off the radiator the coolant can come out the hold around the trans line fitting, where the trans cooler tank - inside the radiator case - sticks out. No reason to unscrew the fitting if you get the GM adapter fitting, snaps right into that sping fitting and has an AN thread on the otehr side. Waiting on that fitting right now to cut it into the trans lines.

 

[mfdrookie516]

Just remember to have the fluid go through the aux cooler, then the radiator, not the other way around. This is especially important if you live somewhere that it gets cold in the winter.