Not a good idea to bypass radiator...

darkstar_one

Registered User
Ok, i heard many of you guys say you should bypass the radiator when installing a TRANSMISSION cooler, i know for damn sure that u shouldnt, why do u ask? unless ur cooler is the size of a condenser then u shouldnt, i dont think an 11x8x3/4 cooler is enough to cool down a huge full size transmission especially when u have a SUPERCHARGER hooked upto to the engine. I popped in my cooler yesterday, and it seemed fine on the way to work, i noticed how quickly it got HOT when i checked for leaks after the installtion, it was like an instant heat source. Well today i drove my mom to the store and i noticed my car was kinda acting funny, i thought, damn the transmission is burning up, well i wasnt pushing the car to its limits or anything, i noticed that it was the same symptoms as when my other transmission burnt up from doing the damn same thing, bypassing the radiator, so i said, ****!, well good thing was my mom took forever at the store and it was enought to cool down the engine and the fluid and get it back to normal, well on the way back home i noticed nothing, until i was almost home, i noticed my center console was getting a lil bit too hot, so i got home as slow as i could, well when, i disconnected the hose to hook it up to the radiator i noticed the fluid was extra thin, and i said, damn its burnt up, well i turned on the car to check for leaks and nothing, leak free, i touched the cooler and it wasnt as hot as before, about 10 - 25 degrees cooler, especially on the return side, now when i felt that i got happy again. Well tommorow ima pump out about 2 - 3 quarts of fluid and pour in some LUCAS TRANSMISSION FIX. I dont recommend anybody bypass the radiator when installing a transmission cooler, i dont think its enough to cool down the transmission by itself, what i did, i added it after the radiator, the fluid goes in through the radiator, then out and into the cooler i bought, I think the radiator is enough to cool down the transmission by itself and therfore should not be bypassed when installing a transmission cooler, it should be added after the fluid goes into the radiator.

TIPS:the upper metal line for the cooler coming out of the transmission is the sending line, the bottom is the return line. :D

What do you guys think?
 
darkstar_one said:
Ok, i heard many of you guys say you should bypass the radiator when installing a TRANSMISSION cooler, i know for damn sure that u shouldnt, why do u ask? unless ur cooler is the size of a condenser then u shouldnt, i dont think an 11x8x3/4 cooler is enough to cool down a huge full size transmission especially when u have a SUPERCHARGER hooked upto to the engine. I popped in my cooler yesterday, and it seemed fine on the way to work, i noticed how quickly it got HOT when i checked for leaks after the installtion, it was like an instant heat source. Well today i drove my mom to the store and i noticed my car was kinda acting funny, i thought, damn the transmission is burning up, well i wasnt pushing the car to its limits or anything, i noticed that it was the same symptoms as when my other transmission burnt up from doing the damn same thing, bypassing the radiator, so i said, ****!, well good thing was my mom took forever at the store and it was enought to cool down the engine and the fluid and get it back to normal, well on the way back home i noticed nothing, until i was almost home, i noticed my center console was getting a lil bit too hot, so i got home as slow as i could, well when, i disconnected the hose to hook it up to the radiator i noticed the fluid was extra thin, and i said, damn its burnt up, well i turned on the car to check for leaks and nothing, leak free, i touched the cooler and it wasnt as hot as before, about 10 - 25 degrees cooler, especially on the return side, now when i felt that i got happy again. Well tommorow ima pump out about 2 - 3 quarts of fluid and pour in some LUCAS TRANSMISSION FIX. I dont recommend anybody bypass the radiator when installing a transmission cooler, i dont think its enough to cool down the transmission by itself, what i did, i added it after the radiator, the fluid goes in through the radiator, then out and into the cooler i bought, I think the radiator is enough to cool down the transmission by itself and therfore should not be bypassed when installing a transmission cooler, it should be added after the fluid goes into the radiator.

TIPS:the upper metal line for the cooler coming out of the transmission is the sending line, the bottom is the return line. :D

What do you guys think?

IMHO it is better to bypass the built-in cooler. This is because the transmission adds heat to the cooling system, and you want the engine to run at a constant temp, but depending on road conditions, the transmission may opr may not be running hot. Therefore you want a separate cooling system fo r the transmission.

TCI transmissions says:
Should I use an external transmission cooler in conjunction with the oil cooler supplied in the radiator?

Answer: Unless operating in an environment where the outside temperature is below 0°F, you should cap off the radiator cooler line openings and run your cooler lines directly to a new cooler mounted in front of the radiator. This allows the transmission to have its own cooling system and doesn't allow the engine water temperature to heat the fluid.

Mike Donley
 
I tried it both ways, USE the factory one also. Just the aftermarket one wouldn't keep my tranny cool enough for me (I got the Huge B&M 28000# cooler). If I drive it hard on twisty roads it would climb above my "safe" range of 180* , with it running threw the B&M then the Radiator I NEVER see above 180* no matter how hard I run it.
 
I've tried both with and without the radiator cooler on two different cars. The center console and transmission hump near the driver's thigh don't heat up anymore. Darkstar_one, if yours is heating up, it may be a sign of other problems.
 
I agree with J.D. You might have something else causing your problem.

I bypassed the radiator and put in one of those 28K coolers in front of the AC condenser. The temp in the pan was usually 160*, with max no more than about 180*, even here in SoCal.

Next I changed to a non-locking converter and, at the same time, had to relocate the trans cooler to the driver side fender well, and added a fan to it. My average temps raised about 20*-30* and spiked even higher under hills & hot air. But I don't ever recall noticing the console getting hot.

I'd suggest installing a trans temp gauge right away and let us know what the numbers are under various conditions. Meanwhile, I'd take it easy on the trans.

Here's some related info on trans fluid temps:

trans_failure_temp_chart.jpg


Good luck!
 
Tansmisions do not operate properly at lower temperatures....I believ ethey should be somewhere in the 180 degree range
 
supplemental coolar first

Absolutely correct, Damon. Hooking up the supplemental cooler after the rad cooler is a bad idea. The reason is that the tranny fluid is coming into the supp. cooler around 180 degrees and gets lowered to ambient temps. The whole idea of cooling the tranny fluid in the rad is to buffer the temperature, not get it as low as possible. The tranny and the engine both operate best around 180*F. if the tranny is run too cool, the bands start slipping in there is more wear. If the engine is run too cool, your fuel mileage starts to really suffer.

The supplemental cooler should go before the rad so that in really cold weather, the fluid is _warmed_ by the engine coolant.
 
I wanted to buy one of those universal radiators for my car...problem is, none of them have tranny coolers built in. Could I run two B&M coolers in a row? I don't drive this thing in the winter, so I don't think I'd ever overcool it. Just wondered what everyone thought about this. I think Dave N. did this also...maybe he'll chime in here.
 
I've got a 9.5" non locking converter and have been running with a stand alone cooler for about two years. I'm using dual B&M 28K stack plate coolers bolted back to back with an 800 cfm fan wired to run constantly.

The pan temp gets up to 150 degrees within a few miles and temps generally stay around 180 and the hottest is around 200. I didn't want the heat from the transmission increasing coolant temps, and even mounted the coolers in the drivers side fender to avoid putting hot air into the radiator.

With the converter I've got, it generates enough heat to quickly warm the fluid, so it doesn't need to get any heat from the radiator.

David

PS: Turbo car is set up the same, except the trans cooler is bigger and the fan has a thermostat switch to turn the fan on at 160 degrees.
 
David Neibert said:
I've got a 9.5" non locking converter and have been running with a stand alone cooler for about two years. I'm using dual B&M 28K stack plate coolers bolted back to back with an 800 cfm fan wired to run constantly.

The pan temp gets up to 150 degrees within a few miles and temps generally stay around 180 and the hottest is around 200. I didn't want the heat from the transmission increasing coolant temps, and even mounted the coolers in the drivers side fender to avoid putting hot air into the radiator.

With the converter I've got, it generates enough heat to quickly warm the fluid, so it doesn't need to get any heat from the radiator.

David

PS: Turbo car is set up the same, except the trans cooler is bigger and the fan has a thermostat switch to turn the fan on at 160 degrees.

Same here, have had a stand alone on mine for 4 years.

Mike Donley
 
well, i think it all depends on what area u live on right? some of u live on open highway area, i live in the ghetto, in south central los angeles and its mostly stoplight here, thats why i dont think i can just use the tranny cooler by itself??? what i ment by the console getting hot was actually around it, the rug, the lil camel hump got real warm, not as in the whole console but the rug on the hump, maybe i should of explained my self better.
 
I understood you. The carpet on the sides of the transmission hump would heat up before I installed the coolers. You have a valid point about driving in stop and go traffic; I don't have much experience with that. But I have driven my cars over the Grapevine, to Barstow, Bakersfield, Las Vegas, the Donner Pass ,Nebraska, etc. without the carpet heating up. My coolers are even mounted directly onto the condensers.
 
Back
Top