Re: Oil leak - Cylinder Base

Bruce Crain

Nothing on the threads.  The thread locker goes in the silk thread around the through bolt.  My mid engine through bolt has been dry for years.  The left two through bolts have not.  Today I hope to finish plumbing everything together for runup then cowl and fly.  Hoping for the best!

On Mar 22, 2020, at 10:40 PM, Phil Lankford via Groups.Io <britmcman@...> wrote:

I am not sure you wouldn’t (double negative?) get a similar positive seal on those threads if you were to just dress them with Hylomar without the silk thread trick. But I’m listening. 

Phil Lankford  

On Mar 21, 2020, at 2:45 PM, Bruce Crain <jcrain2@...> wrote:

YepI  That would be correct on the actual through bolt.  I did the silk thread with thread locker or RTV in the thread. 
I did both left and right ends to keep from leaking on either side.  You will need to pull both 2 and 3 cylinders away from the case halves. 
When you start wrapping the thread just keep wrapping it until it starts to fit snugly.  Then do the other end and make them both fit snugly.  I think I wrapped them at the outer ends but not outside the side of the case.  You don't want to let the thread and locker hold the cylinder away from the case half!  Add the thread locker to the thread and push the through bolt into place.  It should be snug enough to keep it in place but not enough to keep it from going into place.  
When you torque the bolt try to keep the ends fairly symmetrical.
My leak has been on the left front side of the case.  There are 2 bolts that thread into the case half on the other side.  I thought I might need to check out the cylinder base flat O ring but D and B Engines said the leak never happens with that base o ring.  He said the 2 bolts are the culprit.  I affirm that as I have seen oil coming out of the threads.
I finished remounting the cylinder and torquing the base nuts and installing the new push tube oil return tubes.  I will most likely finish plumbing the rest this week while Honey Lamb is working.  I get lonesome at the hanger so I came home to "entertain her"!  wink_smile
I will shout out loud if I can get this 0200 dry!
Bruce Crain 

---------- Original Message ----------
From: "Jim Patillo" <Logistics_engineering@...>
Subject: [Q-List] Oil leak - Cylinder Base
Date: Sat, 21 Mar 2020 09:57:07 -0700

Hey Bruce,

I also have an oil leak I’ve been putting off fixing on #2 and #3 cylinders. I think it’s the thru bolts leaking.
I’ve heard that the leak can be stopped by pulling the cylinder away, pushing the thru bolt out a little, wrapping silk thread around the bolt shaft, pushing back in place  and reinstalling the cylinder.

Please let me know what you found and how you repaired it. 

N46JP - Q200

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