External Transmission Cooler in series with the radiator cooler?

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Nov 9, 2020
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Hi,

I would like to know if i should install my external transmission cooler in series with the radiator cooler or install the external cooler only bypassing the radiator cooler? The cooler I'm interested in is a plate- fin type, Anyone have any recommendations? The vehicle is my 04 Acura MDX touring...Thanks.
 
I run them through the add-on cooler first, then to the radiator cooler. I think helps the overall cooling of the vehicle and helps the trans warm up and not overcool for driveability in the Winter. Others may have a different viewpoint.
 
I think OEs go through the rad, then cooler. Helps get the trans fluid to operating temp. The when trans fluid needs cooling the coolant gets the first shot, then the external cooler gets the next. Maybe some advantages on doing what Clean Sump is mentioning. Especially if the cooling system is at max capacity already.
 
My toyota and truck both have factory, dual coolers.

Keep in mind the radiator heat exchanger is in the cold end of the radiator, sitting in water that is generally around or slightly above t-ambient (far below engine coolant temperature) unless the radiator is saturated, at which point the thermostat is fully opened and the radiator is getting full engine flow. I say this to say, I generally doubt the heat exchanger helps to warm the transmission in cold weather for most conditions/applications.

Granted, some cars have the exchanger somewhere in the coolant circuit other than the cold tank (like a heater core bypass loop, like my mazda) which would have different results.

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Hi,

I would like to know if i should install my external transmission cooler in series with the radiator cooler or install the external cooler only bypassing the radiator cooler? The cooler I'm interested in is a plate- fin type, Anyone have any recommendations? The vehicle is my 04 Acura MDX touring...Thanks.
I' ve done it both ways.
Both worked, but I would continue to use the radiator cooler, unless its leaking (yes it happens).

As far as going from trans to radiator cooler 1st or after the new cooler, again both ways work well. My overall high fluid temps drop about the same.

Maybe thru the rad after the new cooler warmed trans up a little faster. Not going to notice or give any real benefit.
 
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