Rocker box gaskets leaking

Discussion in 'Engine, Fuel and Exhaust' started by goody, Sep 10, 2009.

  1. goody

    goody New Member

    1995 FLHTC-U, my rocket box gaskets are being pushed out after I had rebuilt the cylinders due to a blown head gasket. I rebuilt everything according to the manual, and have no problems with the exception of the gaskets. The rocker covers were placed on, centered and torqued to specs. I havent horsed on the engine and the gaskets was pushed out very quickly.
    What could cause this?
  2. Bud White

    Bud White Well-Known Member Retired Moderators

    2 piece or 3 piece boxs seems there was a problem with the gaskets pushing out or a change in gasket material

    here is a post

    Fatboy EVO leaking oil - Harley Davidson Community

    Im sure Glider will offer more about this i coudl only find the one post really talking about it
    Last edited: Sep 10, 2009
  3. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

    Normally the lower rocker gaskets are the ones that leak there is a one piece metal gasket as a replacement this doesn't seem to have any problems
    i bought a rocker box gasket kit using the hd part number for the kit and got the new gaskets in it

  4. goody

    goody New Member

    This isnt the lower gasket. I do have the metal gasket on the lower case. The gasket pushing out is the one between the top and middle case.
  5. Breeze3at

    Breeze3at Well-Known Member

    I remember it was a reoccuring Evo problem, seems like it was most often the left rear.
    Harley made many revisions, and I don't think they ever got it right, problem seems that the mating area is very narrow and they squish. I think the ones I used on my '92 were Comotec, still dry. There were also some other good ones James and Janes? Gosh, that was 14 or more years ago.
  6. Dan89FLSTC

    Dan89FLSTC Banned

    On my `89 the middle part became warped, it was bowed out so that the gasket would not seal. Into the scrap pile they went. I replaced them with units from Drag Specialties, quite a bit less money than the dealer wanted.
  7. zoo-mon

    zoo-mon Member

    I had a similar prob. with an evo motor. The top rocker cover gasket did the same thing when i tightend the bolts. The gaskit surface seemed to have a groove. except in a radiused area in the front of the head. And this is where it pushed out or in. Gaskits didnt cost that much. So I got a new one until it finally sealed. One thing that helped though. I cleaned the surface area real good with brake cleaner removeing all the oil. With the rocker cover real clean and dry it sealed. It drove me crazy til I got it to stop leaking. The gaskit that did the trick was a gray one, the black ones didnt work. Best of luck.
  8. HarryB737

    HarryB737 Junior Member

    I had real good luck with a simular problem on my '07 sportster. My front valve cover started to seep, so I did some research on different gasket companys. I ordered a rocker box gasket set from a company called "Cometic" and had very good success with a good seal 1st time around.
    If you're interested check them out on the Web or their phone # is (440)354-0777. They have all types of Gaskets for Harleys... Good Luck.
  9. goody

    goody New Member

    Thanks for the info. I did all the above (cleanliness, etc) It just seems like there is too much pressure in the rockers? somehow? Someone was talking too high crank pressure, but I dont know how that could occur or be corrected. I will look into Cometic and new covers at Drags to see how different they are.
  10. gtnot

    gtnot Member

    Is it possible that either the head breathers or umbrella valves are clogged/non-functional?