# Brown Foam in Radiator



## Wayne Locke (Dec 1, 2019)

1989 Ford 6610. I just bought this tractor. Brown foam in radiator. See attached pic. The brown foam didn't smell or feel like engine oil or any other oily fluid. I didn't see this when I checked coolant when I tried out the tractor last week. But I looked at it while tractor was cool. The pic is after running it about 25 minutes driving it home. I drained and thoroughly flushed the radiator and block through the block petcock drain. I then filled it with just water and ran tractor for 2 hours under fairly heavy load. After it cooled down, I checked the radiator and saw almost no contamination. What do you all think caused this? Maybe the previous owner hadn't flushed coolant system in years?


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## Hoodoo Valley (Nov 14, 2006)

It's usually an indicator of a blown head gasket. They could have put some form of stop leak in it, might be why you don't see it again after changing it.


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## marc_hanna (Apr 10, 2017)

Could just be bacterial growth also, of the coolant wasn’t properly maintained. 

I would do a thorough clean of the cooling system with one one of the specialty cleaners or with a citric acid water solution to make sure you get any deposits and scale out.


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## Wayne Locke (Dec 1, 2019)

Hoodoo Valley said:


> It's usually an indicator of a blown head gasket. They could have put some form of stop leak in it, might be why you don't see it again after changing it.


Thank You !


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## Wayne Locke (Dec 1, 2019)

marc_hanna said:


> Could just be bacterial growth also, of the coolant wasn’t properly maintained.
> 
> I would do a thorough clean of the cooling system with one one of the specialty cleaners or with a citric acid water solution to make sure you get any deposits and scale out.


Thank You !


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## Hacke (Feb 22, 2011)

Check that the thermostat is clean. Or better, just put a new one in.

Edit
***
By the way, if there is slime and slush behind the thermostat, remove the lower radiator hose from the water pump and flush with a garden hose at the pump, through the engine block and out through the opening where the thermostat was.
When the water is clear, connect the hoses, without putting the thermostat back. Fill the system with a cleaning liquid of your choice (dishwasher liquid/tablets solution or some commercial product, whatever). Run the engine warm, let it rest for an hour or two. Empty the system and flush like before with the garden hose. Flush the radiator (cap on) with the garden hose, first from to the bottom hose on the radiator, then from the upper hose.
***


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## Wayne Locke (Dec 1, 2019)

Hacke said:


> Check that the thermostat is clean. Or better, just put a new one in.
> 
> Edit
> ***
> ...


After running tractor again today for about 2 hours under heavy load and then once again draining the cooling system, I'm pretty sure its just rust and sludge build up. When I drained it again today I collected some in a coke bottle and let it sit for hours. The sludge went to the bottom and the water to the top. That indicates no oil. Also, I did not gain or lose any oil or water during the 2 hour run. I also removed the t-stat and the top hose with it. There was lots of sludge in the hose. I'm going to flush it with some radiator flush of some kind tomorrow.


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## Dmfoste1 (Apr 22, 2019)

I had a similar situation on sisters 2001 Dodge truck. She had someone of what you have shown in the picture, like a frothy chocolate shake. Yours looks a little dried out. As it turns out it was transmission fluid leaking into the radiator via the radiator. There's a higher pressure in the transmission then there is in the cooling system, therefore the transmission pushes fluid into the radiator. This is of course was on an automatic transmission with the cooling lines from the transmission going to the radiator. It did not have a separate transmission cooler on it. I changed the radiator out with a new one, flush the engine out with a lot of water and no thermostat and the issue was solved. No harm was done to the transmission because there was still fluid trying to push into the radiator. I imagine if the transmission gets too low the coolant from the radiator would then push back into the transmission, but I never got to that point. The way we first noticed it is her truck was overheating for no apparent reason. Hope this helps. Sorry I don't have a picture saved, but I bet it'll come up on and internet search.


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## Hacke (Feb 22, 2011)

I do not know how the different types of leak fixing products (Bar's Leak for instance) behave, but maybe it is the remains of an effort to fix a leak?

Maybe different types of coolant have been mixed?


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## bmaverick (Feb 20, 2014)

Looks like that killer-engine coolant called DEXCOOL. That stuff will turn a cooling system into brown mud in a heart beat, then to brown chocolate cement thereafter.


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## Wayne Locke (Dec 1, 2019)

bmaverick said:


> Looks like that killer-engine coolant called DEXCOOL. That stuff will turn a cooling system into brown mud in a heart beat, then to brown chocolate cement thereafter.


The brown stuff in the cup in the picture was like powder after it dried. When I changed the T-stat there was brown residue in the hose. All looks good after flushing several times and using a alkaline flush fluid then refilling with 50/50 antifreeze. Who sells dexcool? I will avoid it.


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## Wayne Locke (Dec 1, 2019)

Hacke said:


> I do not know how the different types of leak fixing products (Bar's Leak for instance) behave, but maybe it is the remains of an effort to fix a leak?
> 
> Maybe different types of coolant have been mixed?


May have been from fix-leak but after flushing and refilling, I have not found any leaks. If was fix-leak then it worked


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