Aftermarket ATF cooler - Before or after radiator?
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That's a good question.
As an industry standard, the cooler should go after the heat exchanger in the radiator if it's factory fitted or as a genuine accessory. They are always a full flow installation, "in series" and no thermostat.
However.
Seeing as there's a thermostat which only partially closes I think it likely depends upon the opening temp of the thermostat whether it goes before or after the heat exchanger in the radiator.
And it would likely be intended to be installed in parallel with the factory cooling system with a thermostat. I think.
I would be inclined to go with the simplest installation and omit the thermostat and run it in accordance with industry standard, and have the cooler in series after the heat exchanger in the radiator. This type of installation has proven to work effectively in the past for OEM's with quite small coolers measuring about 10" x 4" and 1.5" thick with a single "U" shaped loop through it.
It's really only to keep a lid on transmission fluid temps to keep the fluid from getting "over cooked" and preventing thermal runaway while towing.
As an industry standard, the cooler should go after the heat exchanger in the radiator if it's factory fitted or as a genuine accessory. They are always a full flow installation, "in series" and no thermostat.
However.
Seeing as there's a thermostat which only partially closes I think it likely depends upon the opening temp of the thermostat whether it goes before or after the heat exchanger in the radiator.
And it would likely be intended to be installed in parallel with the factory cooling system with a thermostat. I think.
I would be inclined to go with the simplest installation and omit the thermostat and run it in accordance with industry standard, and have the cooler in series after the heat exchanger in the radiator. This type of installation has proven to work effectively in the past for OEM's with quite small coolers measuring about 10" x 4" and 1.5" thick with a single "U" shaped loop through it.
It's really only to keep a lid on transmission fluid temps to keep the fluid from getting "over cooked" and preventing thermal runaway while towing.
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It is meant to be fully open at 180 degrees F which is a good temperature.
I considered getting a smaller cooler and going without the thermostat for costs sake, but I've read that too cool of fluid is just as bad as too hot of fluid so it seems being able to keep the fluid in a sweet zone is the best option
I considered getting a smaller cooler and going without the thermostat for costs sake, but I've read that too cool of fluid is just as bad as too hot of fluid so it seems being able to keep the fluid in a sweet zone is the best option
How cold does it get there where you are? Unless it stays below freezing for extended periods of time, I would skip the thermostat as it really is not needed for mild to hot climates.
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so that the radiator can keep the fluid "warm" if the cooler makes it too cool...
So, what is the temperature of the radiator cold tank and the incoming ATF at the same time? Can the cold tank ever be warmer than the ATF? I don't think so, but I haven't checked.
I'd put the extra cooler after the radiator unless your goal is to reduce the load on the radiator for better engine cooling under very heavy load in hot weather.
so that the radiator can keep the fluid "warm" if the cooler makes it too cool...
So, what is the temperature of the radiator cold tank and the incoming ATF at the same time? Can the cold tank ever be warmer than the ATF? I don't think so, but I haven't checked.
I'd put the extra cooler after the radiator unless your goal is to reduce the load on the radiator for better engine cooling under very heavy load in hot weather.
I've got a transmission cooler on my work bench but haven't installed it yet. My truck has 2 electric fans behind the radiator so I don't have much of a choice, without a lot of fabricating, but to mount the cooler in front of the radiator. I've done a couple of these and always mounted the cooler in front of the radiator. I never installed a thermostat for the transmission cooler either. Never had a problem with engine running hot and the transmission was a lot cooler.
FWIW, on my BMW it is in front of the radiator. My Sienna has one that is off to the side and is cooled with airflow from a duct, but also has one in the radiator. The BMW does not, only the one in front.
Originally Posted By: kschachn
FWIW, on my BMW it is in front of the radiator. My Sienna has one that is off to the side and is cooled with airflow from a duct, but also has one in the radiator. The BMW does not, only the one in front.
My 2001 RX300 had just the trans cooler off to the side like you mentioned. but my 2005 RX330 has that, as well as the cooler in the radiator.
FWIW, on my BMW it is in front of the radiator. My Sienna has one that is off to the side and is cooled with airflow from a duct, but also has one in the radiator. The BMW does not, only the one in front.
My 2001 RX300 had just the trans cooler off to the side like you mentioned. but my 2005 RX330 has that, as well as the cooler in the radiator.
Yeah, my Sienna definitely has a radiator tank cooler in addition to the aux one. It reflects that the additional cooler was part of the towing package that year (and can save your bacon on this transmission). The cooling air exits inside the left wheel well and on warm days is hot.
My old BMW just has two lines coming from the transmission to the cooler mounted in front of the radiator. At first you think you can remove the radiator without disturbing the transmission lines, but in typical BMW fashion due to the way it is attached, you cannot.
Originally Posted By: lexus114
Originally Posted By: kschachn
FWIW, on my BMW it is in front of the radiator. My Sienna has one that is off to the side and is cooled with airflow from a duct, but also has one in the radiator. The BMW does not, only the one in front.
My 2001 RX300 had just the trans cooler off to the side like you mentioned. but my 2005 RX330 has that, as well as the cooler in the radiator.
My old BMW just has two lines coming from the transmission to the cooler mounted in front of the radiator. At first you think you can remove the radiator without disturbing the transmission lines, but in typical BMW fashion due to the way it is attached, you cannot.
Originally Posted By: lexus114
Originally Posted By: kschachn
FWIW, on my BMW it is in front of the radiator. My Sienna has one that is off to the side and is cooled with airflow from a duct, but also has one in the radiator. The BMW does not, only the one in front.
My 2001 RX300 had just the trans cooler off to the side like you mentioned. but my 2005 RX330 has that, as well as the cooler in the radiator.
The factory installed aux trans cooler on my Ranger is installed directly behind the grille/bumper, in front of the radiator and a/c condenser. It is the most forward mounted fluid containing part on the truck.
It is controlled by a thermostat though, and opens at 180-190*F according to what I have read. The trans rarely reaches those temps (in my application, higher temps are normal in others).
It also runs the fluid through a radiator cooler constantly, no thermostat on that.
I would guess that in Australia, you'd be fine mounting even a non-thermostatically controlled cooler as far forward as possible. You do want the ATF to reach full operating temp though. My truck shifts best when when warm (above 145*F).
It is controlled by a thermostat though, and opens at 180-190*F according to what I have read. The trans rarely reaches those temps (in my application, higher temps are normal in others).
It also runs the fluid through a radiator cooler constantly, no thermostat on that.
I would guess that in Australia, you'd be fine mounting even a non-thermostatically controlled cooler as far forward as possible. You do want the ATF to reach full operating temp though. My truck shifts best when when warm (above 145*F).
We have always wondered if the long engine and trans life we regularly get out of our 3500 GMC Savana vans is due to the oil and the transmission fluid being run through the radiator.
I have always wondered how this might extend service life by having consistent temps in ALL the fluids...
I have always wondered how this might extend service life by having consistent temps in ALL the fluids...
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