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Oil leak impossible to fix

Discussion in 'The Garage' started by DANIEL RAMOS ALTEMIR, Apr 13, 2019 at 1:53 PM.

  1. DANIEL RAMOS ALTEMIR

    DANIEL RAMOS ALTEMIR XS400 Member

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    spain
    Hi, I bought a Sanglas 400y three years ago and has been leaking on the left cover (alternator) since then some days a couple drops, some days more.
    My bike has the same engine as the xs400e so I've been reading the forum to fix this leak she has but it has been impossible. I have tried a new gasket, paper gasket, orange sealant, gasket+sealant and the leak is still there.

    Sincerely, I don't know what else I can do...any suggestions would be appreciated and if you ever ome to Barcelona, you have a friend
     

    Attached Files:

  2. DANIEL RAMOS ALTEMIR

    DANIEL RAMOS ALTEMIR XS400 Member

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    spain
    This weekend I've tried to change gasket for sealant and let the sealant cool, anyonhe has experience sealing the rubber of the alternator cable?
     
  3. DÉU N'HI DO!

    No experience with that specifically. Not sure about your sealant but must here specify waiting a full day after application before they're put in use. Follow instructions exactly if using sealant.

    Generally best bet is OEM gasket (actual Yamaha branded one). How clean was the surface before you resealed it? Did you get EVERYTHING off?
    http://www.xs400.com/threads/what-is-considered-clean-boot-gasket-mating-surface.18600/

    Had it previously been scraped or gouged in a manner so that the surface wasn't flat? Obviously you want to flat surfaces to begin with. So if you're still having leaks I would truly clean the surfaces to rid then of all the stuff you put on them (takes hours to do a good clean) , then replace with OEM gasket as try to reseal per manual specifications (proper torque and proper sequence with bolts)
     
  4. DANIEL RAMOS ALTEMIR

    DANIEL RAMOS ALTEMIR XS400 Member

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    spain
    Thanks for your reply.
    Last I tried the OEM gasket and same result, leaking cover. I have tried the sealant this last time and let it sit for 5h to dry and form a solid gasket instead of soft, still leaks.

    I cleaned the surface with a cutter razor and made sure all was pretty clean, any suggestions to inspect the surface for cracks and dents and or cleaning? I already checked the link.

    How important is to wrench at the torque specified to avoid leaks?
     
  5. Generally manufacturers don't specify a torque setting because it doesn't matter. They specify so you do it correctly, but I'm not sure what that even is for my bike let alone yours. Unless you're way too tight or loose it shouldn't be causing such a bad leak.

    Hard to say without seeing it, but possible causes should be limited to a handful of possibilities: unclean gasket surface, gouged gasket surface, poor gasket, improper tightening.

    Post some more photos, particularly with it removed if you're going to presumably do that again
     
  6. DANIEL RAMOS ALTEMIR

    DANIEL RAMOS ALTEMIR XS400 Member

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    spain
    This was last weekend, you can see the sealant on the cover and this is the one I used: ceys j28 technobond.

    The leak always comes from the same spots, the lower side of the cover.
     

    Attached Files:

  7. NewHavenMike

    NewHavenMike 1976 XS360C Top Contributor

    Some of the sidecovers can easily be improperly seated. Happened to me with the clutch cover, one if the dowel pins was ovaled and the cover wouldnt fit over it. If you tighten one side first, the cover can become uneven and seat crooked.

    I always snug everything first and maybe give the cover a very light tap with a deadblow before the final snug, which I do in a pattern.
     
    buztabuzt likes this.
  8. BBS360

    BBS360 XS400 Guru Top Contributor

    Could it be leaking around or through the alternator wiring grommet?
    20190416_214359.jpg

    I removed the grommet and smeared liquid gasket around all four sides before reinserting it.
     
  9. DANIEL RAMOS ALTEMIR

    DANIEL RAMOS ALTEMIR XS400 Member

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    Yes, but it also leaks in the lower part of the cover.
     
  10. drewpy

    drewpy Excess twin Top Contributor

    ensure the surfaces are flat using a steel edge

    use 1 gasket (I can see 2 in the first photo) and lightly coat either side with grease
    make sure all dowels are in there as 1 missing would create a large hole which cannot be sealed

    make sure the screws are torqued to 10nm
     
    buztabuzt likes this.
  11. Sure it's not leaking from wire harness and running down to appear as if leaking underneath?
     
  12. DANIEL RAMOS ALTEMIR

    DANIEL RAMOS ALTEMIR XS400 Member

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    spain
    Hard to tell since it all drips in the same direction. I cleaned and sprayed with a white moisture and it revealed the two leaks...

    Any good way to spot a leak?
     
    Last edited: Apr 17, 2019 at 8:43 AM

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