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-   -   Oil leak finally found but what can I do? (https://vansairforce.net/community/showthread.php?t=118814)

brodman@strato.net 10-25-2014 09:35 AM

Bummer
 
The reason the oil is leaking at that location is because that is where the camshaft journal is supplied oil psi. The case has fretted causing the thread seal on the back bone in that area to become compromised and the oil psi is bleeding out from the camshaft saddle. This is a regular problem I see in high time Lyc engines. I see a bunch of good ideas here concerning putting a band-aid on the problem but your first inclination is correct. The correct way to fix the problem involves splitting the case and further more it?s a good sign of more problems to come down the road. (thru bolt leakage, and main bearings shifting) feel free to give me a call if you want to talk about it. 863-655-5000 Jimmy. P.S. check Lycoming SI342 on you injection line clamps. 

chaskuss 10-25-2014 02:53 PM

Hmmm, not quite
 
Quote:

Originally Posted by brodman@strato.net (Post 927833)
snipped P.S. check Lycoming SI342 on you injection line clamps. 

Jim,
I think you meant to type SB 342G, not SI 342, as there is no SI 342. You can download SB 342G below

http://www.lycoming.com/Portals/0/te...stallation.pdf

Charlie

BillL 10-25-2014 03:50 PM

Quote:

Originally Posted by brodman@strato.net (Post 927833)
The reason the oil is leaking at that location is because that is where the camshaft journal is supplied oil psi. The case has fretted causing the thread seal on the back bone in that area to become compromised and the oil psi is bleeding out from the camshaft saddle. This is a regular problem I see in high time Lyc engines. I see a bunch of good ideas here concerning putting a band-aid on the problem but your first inclination is correct. The correct way to fix the problem involves splitting the case and further more it?s a good sign of more problems to come down the road. (thru bolt leakage, and main bearings shifting) feel free to give me a call if you want to talk about it. 863-655-5000 Jimmy. P.S. check Lycoming SI342 on you injection line clamps. 

Thank you.

jdeas 10-26-2014 05:21 AM

Looking better
 
Jimmy, I am worried about fretting. Another data point for this engine. The engine was torn down to install a new cam then sat pickled on a shelf for more than seven years. From conversations with others, all the seals are most likely dried out and prone to leak. I did replace the sump and front seal.

It may come down to to splitting the case but the option of using a ridged filler (Loctite 290) over proseal was to address how fretting may continue with a soft surface treatment where a solid penetrating sealer would help combat it.

Last test flight was 1.5hr and the leak is pretty much gone.:)


I plan to keep an eye on the seam and if it opens back up I'll re-evaluate the situation to split the case. The engine is old but the hrs are lower than expected. Under 1700 TT and only 150 SMOH

As for the fuel lines, there is another clamp just out of the picture. The engine was in a Piper and the lines are as supplied. Reading the document, I appear to be within compliance as to supported lengths, clamps, etc.

Thanks to all for the suggestions!

brodman@strato.net 10-29-2014 12:01 PM

Quote:

Originally Posted by chaskuss (Post 927881)
Jim,
I think you meant to type SB 342G, not SI 342, as there is no SI 342. You can download SB 342G below

http://www.lycoming.com/Portals/0/te...stallation.pdf

Charlie

Your right Charlie... a new revision pops up every day or so.. thanks


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