I installed an aftermarket trans cooler. One of the cylinder shaped ones, approxe 14-16 inches long. I decided to just bypass the stock cooler that runs through the radiator. But the trans cooler I bought gets REALLY hot. If I run the car for a while and touch the cooler its almost too hot to touch. I have a few zip-ties to help hold it in place, those havent melted or anything. But should this thing be getting THAT hot?? Also, I am using braided steel line. Thanks guys.

 

REALLY hot/Too hot to touch is a very subjective guage It's strapped against a radiator that runs around boiling temperature. I think the transfluid runs even hotter then that. The fins are different than an aluminum radiator (thicker fins) so itll feel much hotter than touching your rad.

So the only way to answer "is my cooler running too hot" question is to get an actual temperature reading

 

You should NEVER bypass the radiator! The coolers need to be ran "in series". You'll cook your transmission if you don't run through the radiator first.

Frank
CPT

 

I always heard the rumor that the reason that the tranny is ran through the radiator is to actually warm the tranny fluid in colder climates. But I always said that it didn't make sense since its done on the souther vehicles just like the northern ones, but I thought with an aftermarket cooler you didn't have to use the radiator. I know a guy that says that his tranny runs cooler with the line just looped rather than running it to a cooler or the radiator. That just makes me cringe.

Sorry, I kinda just rambled off there LOL, thanks for the info though Frank. I'll take your word over theirs

 

hhmm. I am not sure how I am going to do that. The line and fittings I am using are a differant size then the radiator. Does this cooler not do as well for cooling as the factory radiator??

 

Think about it like this. If air cooling the transmission fluid was a better idea, I'm sure the auto industry would've saved themselves a huge amount of money by not putting the coolers in the radiator. Water is a MUCH better "cooling medium" than air.
We did many, many tests on cooler, cooler types, and mounting options around 15 years ago. I can tell you without a doubt that running a cooler without going through the radiator IS NOT sufficient enough to cool the fluid.

Frank
CPT

 

I read in a Chevy High Performance Article a while back that it is better to run the tranny fluid through the tranny cooler and then the radiator. Their reasoning was this would cause for the fluid to be cooler when it reached the radiator, resulting in less heat released into the antifreeze (i.e. cooler engine temps).

 

Alright thanks alot guys. I guess I will have to find some way of sending it back through the radiator.

 

Mine actually ran cooler on my guage bypassing the stock radiator.

I have a huge aftermarket cooler though.

 

you always, always, always run it thru the stock cooler first then thru an add on cooler. Water in a better conductor of heat and will bring the trans temp down. Then the aftermarket coolar will help in lowering it even further.

The stock cooler is not there to warm it up or any of them other tall tales. In the heavy duty truck market they actually do install secondary coolers from the factory. My work truck in an F-450. 1st cooler is in the rad and a second cooler is mounted up front.