Jump to content
Sign in to follow this  

Recommended Posts

is it a bad idea to bypass the cooler in the radiator and run an external cooler in front of the radiators? would it damage the trans to run it with just an external cooler? the cooler on my radiator has decided it doesent want to hold the fluid in it at the elbow connection.

Share this post


Link to post
Share on other sites

anyone? i need to know if it would damage the trans to drive it about 20 miles with only the external cooler i installed. i want to get to my friends house so i can get the fitting thats leaking from my old radiator. the cooler is 4 inches wide by 10 inches long and its mounted right behind the grill so it gets airflow blown right throgh it.

Edited by sirtokesalot

Share this post


Link to post
Share on other sites

I considered doing this some time back. However, after checking available space in front of the radiator, I gave up on that idea,  just not enough room, and just too awkward to install. It made a lot more sense to install a new radiator, as I figured the rest of my old radiator wasn't worth saving. Seemed it cost about $100, maybe a little more, maybe a little less. It was super easy to install. It was then, that I realized that a new radiator was the best and easiest solution.

I bought mine on line, Chinese manufactured, never have had a problem with it.

Share this post


Link to post
Share on other sites

well the point is that i have an external cooler already. i figured it out myself i just drove it there and pulled over regularly and checked the trans temp at the pan with a point and click temp gun. unfortunately the fitting on the old radiator is not the same so i messed with the flare end a bit and got it to i tihnk seal up. the trans actually runs around 40 degrees hotter using the radiator cooler vs the 4 inch by 10 inch external cooler. im going to run it throght he radiator cooler a few days to be sure its not leaking then im probly going to hook up the external cooler in line with it as well as long as no leaks from the original one.

 

Share this post


Link to post
Share on other sites

If you only run the external cooler and not through the radiator it will take the transmission significantly longer to warm up especially on the cold days here in CT. 

These transmissions don't typically have an issue were they fail due to them being overheated (excluding the SVXs lol) so running an external cooler doesn't really do much but hurt fuel economy due to the increase in warm up time. 

The transmission fluid going through the radiator actually helps warm up the transmission with the heat transfer from coolant. 

Share this post


Link to post
Share on other sites

Generally lower is better for trans fluid. To a point of course. I run my 700R4 with only independent coolers and on most days it doesn't get up past about 130-140 degrees. Indeed it shifts harder and engages more positively with lower fluid temps (higher line pressure). Trans builders will tell you that anything over 170 will shorten the auto transmission clutch life. If you run no coolant heat exchanger definitely use synthetic as it will perform and flow better at lower temps. 

GD

Share this post


Link to post
Share on other sites

When I get around to installing a trans cooler on our forester I plan to plumb it in AFTER the OEM radiator heat exchanger.  If we convert to an aluminum radiator however, we will lose the factory cooler anyway.

Share this post


Link to post
Share on other sites

well i messed with it again today couldn't stop the leak i could get it to a very slow seeping if i added a rubber washer but no matter how much i tighten it it still leaks. im about to give up and run it with only the external cooler for now. i have a point and click temp gun whats is considered too hot for transmission fluid? i would be pointing the temp gun at the bottom of the trans pan. this way i can watch how hot it gets after a few trips and see if it is enough cooling for it.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×