Do oil coolers need flushing out?

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peter-h

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peter-h
I am replacing my baffles because, at 10 years, they are well knackered and I am sure a lot of air is leaking past them. I can see a rise in CHTs compared to a few years ago. So I will get them re-made using that red silicone material. Here is an article by someone with a similar aircraft. At the bottom of that article is a link to an improved baffle material, which I will try to get.

But the engineer (A&P/IA) also said that I should have the oil cooler flushed because they end up clogged up with muck. And I know a large % of the engine heat ends up in the oil.

The oil cooler looks like the one here. The engine is an IO540-C4.

What would be the best stuff for washing it out?
 
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Ask the A&P - they should have the equipment to do it. Shop I use removes the oil cooler and lets it soak in a bath of Stoddard solvent. Not something to be done at home in the sink.
 
murphey said:
Ask the A&P - they should have the equipment to do it. Shop I use removes the oil cooler and lets it soak in a bath of Stoddard solvent. Not something to be done at home in the sink.
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There are also (typically automotive but same tech) shops that can pressure-flush them (Carefully. They can rupture if they're full of crud.), that specialize in stuff like that.

If you're having trouble finding one, John Frank at Cessna Pilot's Assn in California has a couple he recommends to Cessna folk. A phone call and a small donation to CPA (just to be nice) would probably get the info for your A&P to ship it.

That's my guess anyway, I'm just sharing that he discusses flushing them at his maintenance tech courses for Cessna owners.
 
denverpilot said:
There are also (typically automotive but same tech) shops that can pressure-flush them (Carefully. They can rupture if they're full of crud.), that specialize in stuff like that.
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That's why Ron lets the cooler soak overnight before flushing it out with low pressure.
 
The oil coolers will varnish up on the inside just like the engine.
 
murphey said:
That's why Ron lets the cooler soak overnight before flushing it out with low pressure.
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Understood. I guess I should have mentioned that the shops that specialize usually have other tricks like pumps that pulse rapidly or even use "ultrasonic" vibration to clear the crud during that low-pressure pump-out. Many can also carefully do repairs on bent fins, etc.

Just stiff the typical A&P might not have handy in their shop.

If its *really* gummed up, sometimes a new cooler is easier/cheaper. ;)

The temperature valve is also sometimes a... wait for it... it's Joke Friday after all... sticking point. :)
 
Your local GM dealer (Vauxhal sp?) has a product called X-66 Carbon Remover. Remove the cooler and drain, flush with a high evaporative solvent, blow through with air to dry then fill with X-66 and let soak overnight in a warm oven. Drain, flush and dry again.
 
Maybe I'm leaving a bunch of gunk in there, but I just mate mine up to the nozzle on the parts cleaner in my mechanic's hangar, and hold it there for a couple minutes, then drain it and flush it in the other direction. Do that a couple of times, drain it good, then blow it out with compressed air. Seems to work okay.
 
Henning said:
Your local GM dealer (Vauxhal sp?) has a product called X-66 Carbon Remover. Remove the cooler and drain, flush with a high evaporative solvent, blow through with air to dry then fill with X-66 and let soak overnight in a warm oven. Drain, flush and dry again.
Click to expand...

Boy, I haven't heard the name Vauxhall for a long time. Our family vehicle in Miami, early sixties, seems like it was replaced with a vw.
 
Looks like X-66 is gone, never to be seen in this country again.

SECTION 02: COMPOSITION & INGREDIENT INFO
CAS# FORMULATION Weight/Volume CHEMICAL NAME:

000108112 < 0.0000/5.0000% W 2-PENTANOL, 4-METHYL- https://en.wikipedia.org/wiki/4-Methyl-2-pentanol
000111762 R 5.0000/ 20.0000% W ETHANOL, 2-BUTOXY- https://en.wikipedia.org/wiki/2-Butoxyethanol
000544605 R 1.0000/ 15.0000% W 9-OCTADECENOIC ACID (Z)-, AMMONIUM SALT http://www.chemicalbook.com/ProductChemicalPropertiesCB5913277_EN.htm
007732185 B 0.0000/0.0000% W WATER
008030306 R 35.0000/ 50.0000% W BENZIN (Benzine?) https://en.wikipedia.org/wiki/Petroleum_ether
068476868 R 1.0000/ 15.0000% W Petroleum gases, liquefied, sweetened http://hazmap.nlm.nih.gov/category-details?id=10747&table=copytblagents
 
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Oil coolers get gunked up with varnish and sludge. The sludge can be corrosive, since it's a product of oil and water and it's acidic. Flushing out an old cooler can remove all the crud that was keeping it sealed up, and now all those empty corrosion pits leave thin spots in the metal that could start leaking. Old radiators can do the same thing.

There are aftermarket coolers that work fine and don't break the bank. If you pay your shop to clean the cooler it could cost more than a new one.

Dan
 
Don't mess with it. Send it to Pacific Oil Coolers.

Better yet, buy a new cooler. The traditional old oil cooler overhaul services have been restricted (EPA) in their use of the good chemicals. An overhaul is not as good as it was 30 years ago.

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