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Trans cooler lines which is which

38K views 44 replies 21 participants last post by  Jon 
#1 ·
Is there a general rule which trans cooler line on the radiator is the forward and the reverse one? I have a 1980 Monte and need to know to hook in the additional cooler in the right place.

Regards
Martin
 
#2 ·
Take the lines loose and start it up and see which one fluid shoots out of. As far as hooking up the cooler I don't think it really makes much differeance if the extra cooler is in line ahead of the radiator cooler or after it
 
#3 ·
Good idea, simple solution! Gonna do that when the tranny is back in.

Furthermore, just tonight a mechanic from the neighbourhood told me it was not a good idea to mount a tranny cooler at all in his opinion. He said the tranny would not reach operating temperature this way. But up to now I've always heared the contrary, that an additional cooler is always a good idea, the Europeans usually even say it is essential. Do you agree that I should mount it?

Regards
Martin

BTW it is a four row cooler about 4" high and 20" wide.
 
#4 ·
trans cooler

The tranny cooler should be hooked up after the original cooler before the fluid goes back to the trans. An easier way to tell which is the return is to start and run the engine, the trans cooler lines will begin to warm up after a few minutes, the warmer one is the feed to the cooler, and the colder one is the return. On your Monte the fluid should come into the bottom of the radiator cooler and out the top. I would install the extra cooler between the top fitting at the radiator and the return line.

I have not heard of any problems with the ATF staying too cold, even here in frigid North Dakota I have not personally seen anything bad, maybe someone else has? Let us all know!

Rick
 
#5 ·
It Makes A Diff IMHO

I think it actually does make a difference.

When the car is cold, the radiator trans cooler actually acts as a transmission heater. It gets the tranny up to optimal operating temp quicker by heating the tranny fluid in the warm coolant.

So, put your auxilliary cooler before the radiator cooler so that it doesn't cool fluid the radiator has heated during warm up.

Also, fluid to fluid is more efficient heat transfer than fluid to air. So, the greater temperature differential when the tranny is hot will benefit the efficiency of the air cooler more than the fluid one I think. The radiator cooler doesn't need the big temperature differential to draw heat off the tranny fluid.

So, auxilliary before factory radiator cooler me thinks.

Anyway, that's my $.02 worth.
 
#6 ·
trans cooler

Yes, I do agree that the factory cooler in the radiator heats up the fluid, actually it stabilizes the temp of the fluid, warming it when the engine is warmer that the trans, and cooling it when the trans is warmer than the engine.

In my opinion, if the auxiliary cooler is before the radiator cooler, whatever heat the aux. cooler took away the radiator cooler will just warm it back up. The aux. cooler would not help at all. If no one has heard of problems with the fluid being too cold going back to the trans, why wouldn't you want to put the aux. cooler on the return line?

Let me know what you think.
Rick
 
#7 ·
WildBill said:
I think it actually does make a difference.

I agree with WildBill.....

Most all automatic transmission parts people say the automatics work better at 180 degrees or so.....and allows the fluid to lubricate and well as make pressure. If the extra cooler is before the transmission ( and that's HOW mine is ) ...it can cool the heated up fluid before it gets to the radiator. IF the transmission fluid is overheated......you can bet money that the radiator is warmed up too..... and you cannot cool the fluid with HOT WATER.....and the radiator does NOT need any additional heat at that time.

On my car ( with a high stall converter ) .....the transmission fluid is cooled before the radiator and ........in it's own little way HELPS the radiator....not hurts it. The radiator cooler then raises the fluid to the desired temperature level ( and dissipates radiator heat...at the same time ) and the Turbo 400 is happy. :D


Just the way that works for me.....I also have a auxiliary filter in line before the cooler.....1 more quart of transmission fluid in line can not hurt IMHO..
 
#9 ·
This has been an ongoing debate for years. Both ways have it's values, as spelt out above. Personally, I agree with Deuce......Oil generally operates at a higher temp than water............but, what do I know.
 
#10 ·
trans cooler

I guess we can agree to disagree! I would like to know if any one has some hard facts on the benefits of hooking the extra cooler up before or after the radiator cooler. I have installed coolers before and the cooler manufacturers recommend installing after the radiator cooler (at least what I can recall), I am not sure what a aux. cooler right from GM, Ford or Chrysler would say.

Again, if any one knows any hard facts why either way is better, we would all like to hear them so we can make our own educated decision. Maybe the ATF companies would have an opinion?

Thanks,
Rick
 
#13 ·
I Agree w Deuce

I agree with your analysis, Deuce. If the tranny is hot, so's the coolant, so put the auxillary cooler before the radiator cooler to help the tranny and the engine.

By the way, that is the reason you should do it this way in south Florida. Getting the tranny to and keeping it at the correct operating temperature is why this is a better configuration in Alberta.

Auxillary befor the factory radiator cooler seems to me to make sense in any climate.
 
#14 ·
According to B&M. This is how I did mine.

The lower line from the TH350, 400, or powerglide tranny is out. This line runs to the lower rad fitting. This enables the fluid to rise and push the air out of the rad cooler. From the upper rad cooler fitting run a line to the aux cooler. The aux cooler should be mounted in such a fashion as to not trap air. The inlet line being connected to the lower connection as to push air up and out. The upper cooler connection then runs back to the upper tranny connection.

If you live in a warm climate the use of the rad cooler is "not" recommended.
 
#15 ·
atlantis said:
Crosley, I guess you would put it after the radiator in a hot climate and before in a cold one. I live in a moderate climate, probably comparable to some east coast regions, therefore I'm in doubt. But from what everybody has written I rather tend to put it before the radiator now.

Regards
Martin
Actually I do not run the radiator coolers in my older cars. I run only a stand alone aux type coolers and no temp control bypass.


My new daily driver vehicles I leave alone. I just drive them , change oil now and then if I remember. ;)
 
#16 ·
Crosley said:
My new daily driver vehicles I leave alone. I just drive them , change oil now and then if I remember. ;)
My 2000 Impala has a setting for (oil life monitoring) among many other things that are making newer vehicles more and more idiot resistant.

bracketeer said:
The lower line from the TH350, 400, or powerglide tranny is out. This line runs to the lower rad fitting. The upper connection then runs back to the upper tranny connection.
 
#17 ·
bracketeer said:
According to B&M. This is how I did mine.

The lower line from the TH350, 400, or powerglide tranny is out.
Also on a 4l60e if anyone wants to know.

If you live in a warm climate the use of the rad cooler is "not" recommended.
I would think that is a typo error, correct?

Now you all have me worried. In my 96 trans am, I have the fluid going through the heat exchanger in the radiator first, then through a 10" x 10" cooler in front of the condenser, then through an 11" x 9" cooler {modified 1996 Chevy 3500 diesel oil cooler} in front of the DS fenderwell with a fan controlled by a 180 deg. fluid temp switch.
This arrangement has served well in keeping the fluid temp down for the last ~5 months in the hot Miss. summer weather with a 3k stall, but I haven't run it in the winter yet.
There have been a few cold nights so far though lately and according to my trans fluid temp gauge, fluid heats up to only ~140 deg. on the highway going to work {night shift}.
If I leave the coolers as they are, what damage will I do?
Am I going to screw up something from lack of,
Deuce said:
and allows the fluid to lubricate and well as make pressure.
I agree with the lube part, but seems to me like it will make pressure fine.
 
#18 ·
Quote:
If you live in a warm climate the use of the rad cooler is "not" recommended.

I would think that is a typo error, correct?
No, what they are referring to is winter driving. If the temp drops anywhere close to 0. The rad cooler actually heats up the fluid. If you do not drive the car in winter or live in a climate where the temp does not drop near freezing. You do not need to use the rad cooler, just the aux cooler.
 
#19 ·
bracketeer said:
No, what they are referring to is winter driving. If the temp drops anywhere close to 0. The rad cooler actually heats up the fluid. If you do not drive the car in winter or live in a climate where the temp does not drop near freezing. You do not need to use the rad cooler, just the aux cooler.
Ahh. I am really slow tonight. 'Rad cooler' not 'aux cooler'.

I'll try to pay attention a little better from now on. :spank:
 
#23 · (Edited)
line orientation makes no difference...here is another set up to ponder , I run a 3200 ,10.5 stall converter, the trans is plumbed to a large (13000btu) B&M cooler with a total by-pass of the radiator. I am fortunate to have the cooler in front of the radiator, 34's have a nice sloping grill that leaves plenty of room for this. I prefer to isolate the two systems, why? not sure , just seems that useing an external cooler and useing the radiator seems to be an oxymoron, two different heat exchangers doing the same job both having different operating parameters would be some how a conflict.............. different strokes as they say ... ... :evil:
 
#24 ·
:D


Hayden......one of the largest and better known transmssion cooler makers says to run the coolers this way...



That's the way I run mine.....except I have the cooler mounted along the frame rail....not in front of my DEUCE radiator shell....

:)
 
#25 ·
Deuce said:
Hayden......one of the largest and better known transmission cooler makers says to run the coolers this way...



That's the way I run mine.....except I have the cooler mounted along the frame rail....not in front of my DEUCE radiator shell....
As far as I was taught in tech, this is the correct way (in Alberta and Sask, anyway). The rad will warm the fluid in the winter, and the coolers I use have a temperature control built in, weather it is a thermostat, or simply a couple larger tubes for the cold, thick oil to pass through. The fluid passes relatively quickly through these larger ones, so little or no additional cooling occurs. As the fluid temperature reaches the point that increased cooling is required, the now less viscous fluid will pass through the many smaller diameter tubes, and extra cooling occurs. In the summer, while not as hot as AZ, the fluid is nearly as hot as the engine coolant, so the greater differential is at the auxiliary cooler, and it does the lions share.
 
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