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Oil leak sources and sealants

cfiidon

Well Known Member
Over the past few years I have noticed a relatively small but pesky amount of oil beginning to accumulate in the lower cowl and drip out of the exhaust opening. Not much, mind you, but a little bit of oil goes a long way.

In late spring I tackled the task of replacing all of my fuel and oil line hoses as they had aged out. The only oil leak I induced during that task was at the bottom of the oil cooler. I disturbed the 45 degree NPT fitting and broke the seal. Loctite 567 on the NPT threads cured that. Major leak cured… on to the smaller annoying ones.

Background: I assembled my ECI XIO-360 from a kit circa 2010 under the supervision of an IA/AP with significant experience. Other than gaskets, the only sealant I remember using is Tite-Seal on any threaded components (where appropriate).

I used a flashlight and black light and found oil drops accumulating on the rear ¼-20 bolts securing the oil sump and some weeping around the ¾ NPT plugs front and rear of the left side. I saw no evidence that it was emanating from any place above that. I drained the oil and removed, cleaned, and reinstalled the NPT plugs with Loctite 567. I removed all seven of the rear oil sump bolts one at a time and did the same. (Proper torque applied)

After a two hour test flight I am pleased to report that there are no oil drips.

I surmise that Tite-Seal works as a suitable sealant but has a life limit. I don’t know enough about Loctite 567.

Does anyone use Loctite 567 on the oil screen cap threads? I usually rely on proper installation of the crush washer but stuff happens.
 
Yes, after years of occasional oil screen dribbles, I started using just a touch of 567 on the screen threads. No more dribbling. Yes, I do use a new crush washer each time.
 
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