Master cylinder leak - any way to solve temporary?

Discussion in 'Dakar champion (950/990)' started by skandero, May 16, 2014.

  1. skandero

    skandero Been here awhile

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    Hello.
    My friend's 990 got a leak from the clutch master cylinder. Not so bad, but annoying. He ordered the rebuild kit...
    But is there any way to solve this issue temporary, before the kit arrives? Can the leaking cylinder fail totally, if it will be disassembled and reassembled again, or reassembling can give a chance to stop leaking?
    Is there any temporary solution?
    #1
  2. renogeorge

    renogeorge Let's ride!! Supporter

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    It is very unlikely that it would fail completely if you can keep fluid in it and don't allow the level to drop so low that air is drawn into the line. You might get lucky and find a seal that would work. As I recall the seals are washer style--not O rings.

    Good luck
    #2
  3. charlie264

    charlie264 Long timer

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    put thicker oil in until the seal kit arrives.....
    #3
  4. DELTATANGO

    DELTATANGO Motorcyclist and Dog Walk

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    Take it apart. Clean it and put it back together again.
    #4
  5. gefr

    gefr Life is a trip

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    The cylinder gets worn and eats into the washer. Replacing the washer and piston, could work for a month at most. Then things take their toll. The best fixture IMHO is replacing or resleeving the cylinder.
    Temporary fix could be using thicker oil as charlie264 suggests, but in heavy traffic you could be struggling with your clutch lever, especially in low temps.
    Cheers.
    #5
  6. skandero

    skandero Been here awhile

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    Thanks for the answers. We decided to wait for parts and rebuild, it is not too hard to add some oil one-two times, while waiting the parts. The leak is not so bad, and I think there is a risk of getting bad leakage in case of cleaning an old cyl and piston...
    #6
  7. Martynho

    Martynho No more Chilegringo.

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    Hi mine looks to be in the same condition. I have been keeping on top of the oil level for a month now awaiting parts here in Chile with no issues (only a slight weep of fluid). The best solution I have seen is to use a master cyl from an EXC. You lose the daft clutch switch but gain by taking out the mirror mount on the master cyl (relocate using a recycled BMW item)
    #7
  8. skandero

    skandero Been here awhile

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    So, looks like gefr was right: we replaced the piston and things were good... for two weeks) Then the leak appears again.
    What replacement ideas do you have, guys? EXC cyl as Martynho said? Radial cyl? Any aftermarket kits? Found http://www.advrider.com/forums/showthread.php?t=655984, but still looking for new ideas)
    #8
  9. gefr

    gefr Life is a trip

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    It needs to get to me though. It is not temporary and it is not fast. Cheers.
    #9
  10. Szepy

    Szepy Adventurer

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    Jul 25, 2007
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    Hungary
    Just one trick (wondering why KTM dealers don't do it everywhere) change clutch oil at every service. I had the same problem with my 950, my friends also had it with the 990. With regular clutch oil change my 990 has 76000km in it and no clutch leaking.

    I suppose this clutch was designed for excs (light and very small) but Adventures run lot more hours before complete rebuilding than EXCs. :)



    BTW if it just started to leak it'll take a few weeks (thousands of km) until they give it up. Just fill them up regularly!
    #10