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Vernatherm Oil Leak

Funguy

Well Known Member
Looking for advice... My O-320 started leaking oil which I discovered after finding a larger than usual puddle on the ground and burnt oil on one exhaust. I tracked it down to the Vernatherm and discovered that there is a Service Bulletin on it. I got a new one and installed it. It came with a new crush washer. I noticed that the old crush washer had a defect on one surface.The leak is almost gone but I am still getting a few drops after a 20 minute run up. So I am sure I am on the right track. Should I try to fix this or stop obsessing and go fly? I got some advice to reinstall with Red RTV smeared on the crush washer but reticent to do that. All advice appreciated!
 
I had a Vernatherm leaking oil at the gasket once as well. It also had a copper crush gasket which didn?t strike me unusual until I referenced the Lycoming Parts Catalog for my IO-360. The gasket called for is a thick aluminum washer. I don?t know if the O-320 uses the same part, but I would venture to guess that it probably is. My parts catalog is in the hangar at the moment. I can get the part number for you tomorrow. Once I replaced the copper crush gasket with the correct part, the oil leak ceased.
 
You need the aluminum washer. Aircraft spruce sells them.

Think about it this way. If you crush the copper washer down that changes the dimmension (lenght) of the vernatherm inside the engine. That in turn changes the tolerances between the tip of the vernatherm and the hole used to bypass/not bypass the oil cooler.

The aluminum washer does not crush.

Even with the aluminum washer i still get drops once in a while.
 
Correct Terminology

I misspoke when I previously said "crush washer". Both the old washer and new washer are aluminum P/N 76510. Thanks for the education...
 
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