AT Fluid in the Radiator

Allan Hamilton

Allan Hamilton

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Aug 25, 2008
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I removed the radiator cap to check the coolant level after the long winter and found transmission fluid in the radiator. I assume the fluid cooler
in the radiator is leaking. There is no sign of coolant in the transmission so far anyway. My plan is to disconnect the cooler lines and install a
larger external cooler then the one I have, and have a good flushing done of the engine cooling system. I have a aluminum radiator that I got at a
GMCMI convention 14 years ago. I never heard of this happening to anyone else. Any comments of suggestions would be appreciated.
--
Al Hamilton,
76 Eleganza II,
Heart of the 1000 Islands, Ontario
 
I would be much more worried about flushing the transmission than I would be about flushing the cooling system.... I "think" atf would be lighter
than coolant, so if you did have coolant in the trans I think it would be in the bottom of the pan....

Not sure what pressure ATF is at as it runs through the cooler, but I would think it would be low pressure, as it should just dump back in the pan
when it reaches the end of the line... So if you have ATF in your coolant, would think the opposite would be true as well...

Would definitely drop the pan on the trans to see what's going on in there....
--
Mark S. '73 Painted Desert,
Manny 1 Ton Front End,
Howell Injection,
Leigh Harrison 4bag and Rear Brakes,
Fort Worth, TX
 
I believe I saw some comments on this site that it is a good idea to use a sacrificial anode on these radiators... So possibly after 13 years there
may be some corrosion that could have caused the breach in the cooler?

--
Mark S. '73 Painted Desert,
Manny 1 Ton Front End,
Howell Injection,
Leigh Harrison 4bag and Rear Brakes,
Fort Worth, TX
 
Thanks Mark, I have a drain plug in the transmission pan so getting out what's in the pan isn't too difficult. Since it hasn't been running for six
months and the coolant was checked for strength last fall and all OK, I hope the fluid hasn't moved out of the radiator.
--
Al Hamilton,
76 Eleganza II,
Heart of the 1000 Islands, Ontario
 
I took ours out of winter storage and found just the opposite,  coolant in the transmission fluid.  I have an Aluminum radiator only 5 years old.  I sent a sample of my transmission fluid to Blackstone labs and they confirmed antifreeze and water in the trans fluid.  I had to flush the transmission NINE TIMES using 20 gallons of transmission fluid before I got good test results from Blackstone labs. I've now bypassed the radiator for Transmission fluid cooling.  What's even more scary is what if the engine Oil Cooler inside the radiator failed.  So I've also installed an auxiliary engine oil Cooler and bypassed the radiator.I've contacted Jim Kanamata because I purchased the radiator from Applied, I haven't heard back from him yet.Sent from my U.S.Cellular© Smartphone
-------- Original message --------From: Al Hamilton Date: 4/20/21 8:13 AM (GMT-06:00) To: gmclist Subject: [GMCnet] AT Fluid in the Radiator I removed the radiator cap to check the coolant level after the long winter and found transmission fluid in the radiator. I assume the fluid coolerin the radiator is leaking. There is no sign of coolant in the transmission so far anyway. My plan is to disconnect the cooler lines and install alarger external cooler then the one I have, and have a good flushing done of the engine cooling system. I have a aluminum radiator that I got at aGMCMI convention 14 years ago. I never heard of this happening to anyone else. Any comments of suggestions would be appreciated.-- Al Hamilton,76 Eleganza II,Heart of the 1000 Islands, Ontario_______________________________________________GMCnet mailing listUnsubscribe or Change List Options:
 
If you haven't run the coach, I would think you should be just fine... But I would definitely drop the pan and flush the cooler lines to be sure
before installing the external cooler....

You could also probably flush the cooler in the rad and then plug the inlet/outlet and keep using the radiator.... But if it is corrosion, I would
also be concerned about the integrity of the engine oil cooler as well....
--
Mark S. '73 Painted Desert,
Manny 1 Ton Front End,
Howell Injection,
Leigh Harrison 4bag and Rear Brakes,
Fort Worth, TX
 
One has to be careful when installing an external cooler for your engine oil. Using the internal cooler (in the radiator) is a fluid to fluid type of
cooler and is more efficient than a air to fluid cooler. So it takes a larger external cooler to have the same cooling effect. The internal cooler not
only cools the oil, but assists in warming up the oil and keeping it at a relatively constant temp, especially in cold weather. With this in mind, it
is important to note that if you install a external engine oil cooler (air to liquid) that you replace the oil filter/cooler adapter with a
thermostatic type of adapter. A thermostatic type of "sandwich" oil cooler adapter will allow engine oil to warm up to operating temps normal
operating temps by diverting the oil back the engine and not to the cooler. At 180* the thermostat will start diverting oil to the cooler. In cold
weather, without a thermostatic type cooler, oil may never reach normal operating temperature keeping the engine from reaching optimal operating
temperature. Here is an example of the type of cooler adapter you might use. JMHO

https://www.improvedracing.com/mocal-universal-thermostatic-sandwich-plate.html

This is not the one I am using and am not sure it is the one used for our engines. I only offer this as an example of what you might look for.
Research this before you buy. Can't remember where I got mine. But when running in hot weather, I can tell when the oil is being cooled by the
external cooler. I can see the oil pressure vary by about 3-4lbs as the oil thickens up as it is being cooled. Oil pressure will then vary from 45
to 48lbs.

--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
 
Another thing I have found out about Aluminum radiators is that there are two ways of securing the radiator tubes to the end tanks. One way involves
using epoxy to secure them to the end tanks. The other way is to aluminum weld them to the tanks. We put a lot of miles on our coach traveling all
over the south during the winter months. We are on our third "epoxy" radiator. It took me that many to figure out what is happening here. With the
many heat/cool cycles, and many miles shaking this radiator down the road, over time the epoxy will deteriorate, and crack then leak. The epoxy type
of securing the tubes cannot be repaired. You can use "Stop leak" but that only lasts until the next part of the epoxy springs a leak. I do not have
experience with the Aluminum weld attachment system, but have heard from others that it is not as prone to cracking, and should it spring a leak, is
more likely to be repaired. Now, the original type radiator that is copper, they can be recored and should you spring a leak, can be solder repaired
by any competent radiator shop. So, before you do radiator work, do your research to make better choices. JMHO
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
 
I much prefer the Brass/Copper over the Aluminum. They can easily be
repaired or recorded, cost less than Aluminum, and if sized correctly for
the intended use, cool very well in adverse situations. And they are
nowhere as sensitive to corrosion, etc. Last for 40 years+.
Jim Hupy
Salem, Oregon

> Another thing I have found out about Aluminum radiators is that there are
> two ways of securing the radiator tubes to the end tanks. One way involves
> using epoxy to secure them to the end tanks. The other way is to aluminum
> weld them to the tanks. We put a lot of miles on our coach traveling all
> over the south during the winter months. We are on our third "epoxy"
> radiator. It took me that many to figure out what is happening here. With
> the
> many heat/cool cycles, and many miles shaking this radiator down the road,
> over time the epoxy will deteriorate, and crack then leak. The epoxy type
> of securing the tubes cannot be repaired. You can use "Stop leak" but that
> only lasts until the next part of the epoxy springs a leak. I do not have
> experience with the Aluminum weld attachment system, but have heard from
> others that it is not as prone to cracking, and should it spring a leak, is
> more likely to be repaired. Now, the original type radiator that is
> copper, they can be recored and should you spring a leak, can be solder
> repaired
> by any competent radiator shop. So, before you do radiator work, do your
> research to make better choices. JMHO
> --
> Larry
> 78 Royale w/500 Caddy
> Menomonie, WI.
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
 
Ask any radiator repair shop about aluminum vs copper brass and they will
all tell you the same thing. If you want it to last use copper/brass.

Sully
Bellevue wa

> I much prefer the Brass/Copper over the Aluminum. They can easily be
> repaired or recorded, cost less than Aluminum, and if sized correctly for
> the intended use, cool very well in adverse situations. And they are
> nowhere as sensitive to corrosion, etc. Last for 40 years+.
> Jim Hupy
> Salem, Oregon
>

>
> > Another thing I have found out about Aluminum radiators is that there are
> > two ways of securing the radiator tubes to the end tanks. One way
> involves
> > using epoxy to secure them to the end tanks. The other way is to aluminum
> > weld them to the tanks. We put a lot of miles on our coach traveling all
> > over the south during the winter months. We are on our third "epoxy"
> > radiator. It took me that many to figure out what is happening here. With
> > the
> > many heat/cool cycles, and many miles shaking this radiator down the
> road,
> > over time the epoxy will deteriorate, and crack then leak. The epoxy type
> > of securing the tubes cannot be repaired. You can use "Stop leak" but
> that
> > only lasts until the next part of the epoxy springs a leak. I do not have
> > experience with the Aluminum weld attachment system, but have heard from
> > others that it is not as prone to cracking, and should it spring a leak,
> is
> > more likely to be repaired. Now, the original type radiator that is
> > copper, they can be recored and should you spring a leak, can be solder
> > repaired
> > by any competent radiator shop. So, before you do radiator work, do your
> > research to make better choices. JMHO
> > --
> > Larry
> > 78 Royale w/500 Caddy
> > Menomonie, WI.
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> >
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
 
Those of you that have had aluminum radiator failures... Are these the Griffin radiator? This is what I have, and I believe it has epoxied end
tanks....
--
Mark S. '73 Painted Desert,
Manny 1 Ton Front End,
Howell Injection,
Leigh Harrison 4bag and Rear Brakes,
Fort Worth, TX
 
Thank you all for the input. I still plan to go to an external good quality cooler, rather than take my original out of the corner and have it tested.
It was put away about 14 years ago with a five year old recore. I don't know who made the aluminum radiator only that they were sold at a GMCMI
convention in Montgomery, Texas about 2007. About the good operating temperatures, for many years we went south in late December so I would partly
cover the radiator and external transmission cooler with a piece of cardboard. Keeping an eye on the temperature gauges made the system work. It also
helped with the cabin heat as well.
--
Al Hamilton,
76 Eleganza II,
Heart of the 1000 Islands, Ontario
 
my understanding from talking to others, is failures have been griffen. However, that means nothing as they were pretty much the only aluminum
radiator for our coaches for a period of time, so the newer superior radiators that are offered up today, just do not have the miles or time on them
yet to see if they are better or worse.

--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
> my understanding from talking to others, is failures have been griffen. However, that means nothing as they were pretty much the only aluminum
> radiator for our coaches for a period of time, so the newer superior radiators that are offered up today, just do not have the miles or time on
> them yet to see if they are better or worse.
>
> I have also seen 2 OEM radiator transmission cooler failures on GMC's. so it is not just an aluminum radiator issue.

Jon,
Failures in copper radiators?
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
 
Finally found receipt and rad info. It is a Griffin bought in 2006. The description and care & maintenance that came with it says it is epoxied over
the aluminum welds. No other problem with it up to now and I wanted to get lower temperatures when hill climbing and very hot days with a car in tow.
It did that so I was happy with it until now !!!
--
Al Hamilton,
76 Eleganza II,
Heart of the 1000 Islands, Ontario
 
How thick are the tanks on the Griffin?

> Finally found receipt and rad info. It is a Griffin bought in 2006. The
> description and care & maintenance that came with it says it is epoxied over
> the aluminum welds. No other problem with it up to now and I wanted to get
> lower temperatures when hill climbing and very hot days with a car in tow.
> It did that so I was happy with it until now !!!
> --
> Al Hamilton,
> 76 Eleganza II,
> Heart of the 1000 Islands, Ontario
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
 
Larry- Probably due to age.

but David Martin for one had that happen... right after he had his tranny rebuilt, he found his ATF full of antifreeze. but Like Ray- he caught
it and flushed gallons of gallons of fluid to clear up the tranny, and installed a Griffen from Jim Buchannan at the time.

there was one more I remember seeing that had a cooler failure. That was years and years ago. I think his caused overheat and engine failure, and
that is why it sticks in my head.

--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
> Finally found receipt and rad info. It is a Griffin bought in 2006. The description and care & maintenance that came with it says it is epoxied
> over the aluminum welds. No other problem with it up to now and I wanted to get lower temperatures when hill climbing and very hot days with a car
> in tow. It did that so I was happy with it until now !!!

Hmm.. As you say, it looks like Griffin uses braze or weld on their rads... The Epoxy is only there for reinforcement..

https://www.griffinrad.com/epoxy_faq.php?tid=44

That seems like an ideal way to construct the radiator...

They also have an interesting FAQ on electrolysis:

https://www.griffinrad.com/electrolysis.php?tid=46

I wonder if the metal hardlines going to the tranny cooler may act as a conductor, which is concentrating possible electrolysis damage there?
--
Mark S. '73 Painted Desert,
Manny 1 Ton Front End,
Howell Injection,
Leigh Harrison 4bag and Rear Brakes,
Fort Worth, TX
 
> > Finally found receipt and rad info. It is a Griffin bought in 2006. The description and care & maintenance that came with it says it is
> > epoxied over the aluminum welds. No other problem with it up to now and I wanted to get lower temperatures when hill climbing and very hot days
> > with a car in tow. It did that so I was happy with it until now !!!
>
> Hmm.. As you say, it looks like Griffin uses braze or weld on their rads... The Epoxy is only there for reinforcement..
>
> https://www.griffinrad.com/epoxy_faq.php?tid=44
>
> That seems like an ideal way to construct the radiator...
>
> They also have an interesting FAQ on electrolysis:
>
> https://www.griffinrad.com/electrolysis.php?tid=46
>
> I wonder if the metal hardlines going to the tranny cooler may act as a conductor, which is concentrating possible electrolysis damage there?

Thanks for this. Did not know about the Epoxy coating thing. When I took it to the radiator shop they told me the tubes were epoxied to the tanks. So
I stand corrected. Next step for me is to check for electrolysis. If this happens to me again, I think I will go back to a Copper radiator. At least
the it will be repairable JWIT.

--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
 
The tanks on the aluminum rad are about 3 1/2 " and 4 " on the original.

In my case about the last foot of each fluid line is rubber. Not that I was trying to prevent electrolysis, but putting in new lines was easier. I
went around the right side of the engine to run them under a heat shield I installed to protect the engine oil lines.
--
Al Hamilton,
76 Eleganza II,
Heart of the 1000 Islands, Ontario
 
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