I was checking the connections in the cooling system for my transmission and I found out an auxiliar cooler was added (I'm replacing it with a B&M stacked plate model), but the lines don't go through the radiator*, as intended, and there are two connection ports in it. Can anyone tell me wich one is the inlet and which one is the outlet? (right now I'm guesssing the upper one is the inlet and the lower one is the outlet). The system should go like this:

Hot ATF from the trans -> radiator inlet -> radiator outlet -> aux. cooler inlet -> aux. cooler outlet -> cool ATF into the trans.

In the aux cooler there is no indication of which one is the inlet/outlet so my guess is I can use them in any order.

*So the ATF isn't currently going through the radiator at all...

 

58 views and not a single comment?... Gee thank guys...

 

be sure to clean out the cooler or make sure it's clean if capped off before hooking it back in.
there is no directional flow of either cooler.you can go in/out either way you want.
for an up/down rad design,id go in on the top and out the bottom.the bottom of is cooler,but i hardly doubt you'd see a degree diff on a gauge lol-not too sure really.but just guessing,going in the cooler part and coming out the slighter hotter wouldn't make sense right? so id do just what your thinking.in the upper,out the bottom.my diesel is side to side on the bottom of the rad.i really would be surprised if your temp gauge would read different either way you tried it though.

might want to install a temp gauge first before the aux cooler upgrade though.hook the rads cooler back up w/ your current aux cooler and check the temps.perfect trans temp is 175F at the pan.either direction from 175F is away from perfection remember.


ahh so close. we'll run with it.

 

Both my 94 E4OD and my 95 C6 are plumbed the same- tranny out to aux. in, aux. out to radiator in, radiator out to tranny in. Also, when your cooler ports are top and bottom, you want it to go in the bottom and out the top so that it forces air out of the cooler as it fills and you don't end up with an air bubble trapped in the cooler reducing the effiecency of it, air likes to rise to the top. Also before adding a cooler, a gauge is a great idea- I put one on my C6 before doing anything else to it and found that no other cooling mods were required- even with my 9.5 foot camper and a 3600 pound trailer of ATVs behind it.You don't want the tranny running too cool as it won't cook out the moisture or have the seals running at their optimum temp. That is why they run it to the aux cooler first and then to the radiator on a factory setup- the radiator can put some heat back in it if the aux overcooled it. Most aftermarket cooler manufacturers recomend doing the radiator first and then the aux because it shows up as a bigger drop on the gauge and makes THEIR product look better.