Results 1 to 10 of 10

Thread: Rocker Cover Oil Leak

  1. #1
    Bowie's Avatar
    Join Date
    Jul 2014
    Location
    West Milford, NJ
    Posts
    139
    Post Thanks / Like

    Rocker Cover Oil Leak

    Not a super cub but I know you guys are the sharpest tools in the bunch. So on my M6 with the O-540J Lycoming, I'm having a problem with one rocker cover leaking. The cork gasket began leaking on two covers, I replaced the gaskets on cylinders 2 and 4 with silicon gaskets, cylinder 2 is doing fine but cylinder 4 held for one flight and then started leaking again. In the last two months I've peened and sanded the original cover with fine grit on a flat pane of glass, swapped out the original rocker cover with a new rocker cover, tried a second silicon gasket, installed a cork gasket with sealer and still leaking, not much but enough to make a mess of the exhaust, firewall and belly of the plane over time. I don't know what I'm missing, I'm at the point where I'm considering using the following gasket maker as a last resort. Anyone care to chime in?
    https://www.permatex.com/products/ga...-gasket-maker/
    Thanks windy thanked for this post
    Likes tbone liked this post

  2. #2
    supercrow's Avatar
    Join Date
    Dec 2008
    Location
    Smith Pond near Millinocket, Me
    Posts
    547
    Post Thanks / Like
    Are you absolutely sure it's the cover or gasket leaking? With the efforts you have made, I would start looking for a very fine crack in the cyl itself or coming down from a push rod tube or ???? Your efforts should have fixed it and I find the fact that it didn't pretty suspect of something else.
    Likes mike mcs repair liked this post

  3. #3
    cubdriver2's Avatar
    Join Date
    Apr 2003
    Location
    upstate NY
    Posts
    10,873
    Post Thanks / Like
    Rip up an old Tshirt into little strips and tie one around the pushrod tube where it meets the cylinder and make a trip around the pattern. I wash the area with starting fluid to get it clean first.

    Glenn
    "Optimism is going after Moby Dick in a rowboat and taking the tartar sauce with you!"
    Likes mike mcs repair liked this post

  4. #4
    Bowie's Avatar
    Join Date
    Jul 2014
    Location
    West Milford, NJ
    Posts
    139
    Post Thanks / Like

    Rocker Cover Oil Leak

    I'll use your method to check on the push rod tube Glenn, I'm hoping that's it and not a crack supercrow. Thanks guys.


    Sent from my iPad using SuperCub.Org
    Likes mike mcs repair liked this post

  5. #5
    stewartb's Avatar
    Join Date
    Oct 2012
    Location
    Wolf Lake, AK
    Posts
    6,596
    Post Thanks / Like
    Check rocker drain fittings, too.

  6. #6
    cubpilot2's Avatar
    Join Date
    May 2003
    Location
    Anchorage Alaska
    Posts
    819
    Post Thanks / Like
    The Silicone gaskets don't like excessive torque.

    50 in lbs. initially and then at least 40 after first flight and thereafter. Install dry.
    Ed
    Likes OldCuby, mike mcs repair, Jonnyo liked this post

  7. #7
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    21,313
    Post Thanks / Like
    All the silicone rocker covers gaskets I have installed say 20 in lbs. hot and 25 cold.
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers

  8. #8
    cubdriver2's Avatar
    Join Date
    Apr 2003
    Location
    upstate NY
    Posts
    10,873
    Post Thanks / Like
    I have had the best luck just making them snug by hand. Plus, with the silicon gaskets it is important that the surface has no oil and is dry before install or it will leak by capillary action. Starting fluid is the best cleaner that I have used to remove an oil film.

    Glenn
    "Optimism is going after Moby Dick in a rowboat and taking the tartar sauce with you!"

  9. #9
    cubpilot2's Avatar
    Join Date
    May 2003
    Location
    Anchorage Alaska
    Posts
    819
    Post Thanks / Like
    Quote Originally Posted by Steve Pierce View Post
    All the silicone rocker covers gaskets I have installed say 20 in lbs. hot and 25 cold.
    Opps: I was quoting from memory "Real Gaskets Service Letter" which had raised the value. I just called them and verified that they changed it back to 25 cold / 20 hot.

    Discussed here. http://www.shortwingpipers.org/forum...e-Value-Change
    Ed

  10. #10
    Bowie's Avatar
    Join Date
    Jul 2014
    Location
    West Milford, NJ
    Posts
    139
    Post Thanks / Like
    Well Supercrow Thanks for snapping me out of my tunnel vision it is a pushrod tube seal leak not rocker cover. Thumbs up to strips and starting fluid Glen.


    Sent from my iPad using SuperCub.Org
    Thanks cubpilot2, wireweinie thanked for this post
    Likes marcusofcotton liked this post

Similar Threads

  1. Rocker oil return clamps that don't leak?
    By Iflylower in forum Experimental Cubs
    Replies: 10
    Last Post: 01-17-2012, 12:21 PM
  2. Bruce Custom Cover Flyaway Lightweight Cover
    By Darrel Starr in forum Cafe Supercub
    Replies: 1
    Last Post: 07-31-2009, 05:55 AM

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •