Gotta bleed the clutch ....again.

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by JOKER650, Aug 22, 2013.

  1. JOKER650

    JOKER650 Long timer

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    Ok ok....I know , the stock slave is no good. :lol3

    But............
    I do not have a fluid leak at the slave or the master, the level does not go down.
    Ususlly every frkn week I have had to bleed the clutch, but on a recent day 1000km fsr ride I had to bleed it once a day.
    It works fine then all of a sudden the lever just feels slightly different and when I pull in the clutch it doesn't quite drag , but when releasing the lever it grabbs sooner(when the lever is only slightly off the grip)
    when I bleed the slave I get a burp of air out of it, the air and a slightly small amount of oil shoot up and out of the bleeder (got me in the eye:lol3....once).
    SO I remove the master cover and the fluid level is ok, but I bleed the entire system anyhow.
    WTF:scratch

    another rider mentioned that maybe it's moisture in the oil and it's boiling in the slave....hmm

    Suup Bro?
    :ear

    NO FREAK'N LEAKS !!
    #1
  2. JOKER650

    JOKER650 Long timer

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    Yeah...every year I throw in a new o-ring and it's good for the year.
    I was wondering if the master cyl could somehow be pumping air into it?
    Was thinking of replacing the slave but it doesn't leak!
    :ear
    #2
  3. Sheep Shagger

    Sheep Shagger Show me your fleece

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    Are you bleeding it with the syringe and pushing oil back into the system?

    But, it sounds more like you have contamination problem. I'd pull master / slave apart clean and re-build them. Replace all crush washers and blow air down the line to clean any crap / contamination out.
    #3
  4. JOKER650

    JOKER650 Long timer

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    OK...well tomorrow I will take the slave off and clean'r out.
    Everything coming out is clean clean clean!
    No I am not using a syringe, never had a problem bleeding before.
    #4
  5. NitroAcres

    NitroAcres MotoBiggots Suck

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    I had to replace mine a few weeks ago, went the Oberon route..and used 7.5wt fork oil (Ohlins is what I had on the shelf)...
    filled the slave before I put the line on, cleaned the master, filled and flushed (about 3 reservoirs full)
    snugged up the banjo while squeezing the lever..then cracked the bleeder and 3-4 lever pulls it was done.

    Rode it around a couple days and just for fun cracked the bleeder got one tiny bubble.

    I like the lever feel, with the Fork Oil & the aftermarket slave, however I am rebuilding the stocker for "just in case" in the future.
    #5
  6. ICERIDER

    ICERIDER Adventure Rider

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    I had to replace my slave cyl a couple of weeks ago. It could have been worse, I was carrying a new Oberon and I was in Gosport so I rode to the local KTM dealer Trevor Pope and bought oil etc.

    The experienced mechanic there popped out to see what I was doing and loaned some advice and bleeding eqpt. The first thing he checked was the Master cyl. Looking for signs of air getting in as the clutch lever is released.

    The last thing he checked was the slave cyl and indeed this was where the oil was dissapearing.

    For bleeding...his method was attach a pipe and catch-bottle to the slave bleed nipple. Fill the Master res. Open the bleed. Stand back and admire the handsome lines of the 10 year old beast and let gravity do it's thing. Keep topping up. Keep admiring. If it makes you feel better then do all the fancy moves and butten it up.

    People talk about moisture boiling, oil boiling etc. I can't imagine the oil getting all that hot. I must remember to put my hand on the pipe/Master cyl next time I ride to test it but I'd be very surprised if it was hot. Any black deposits in the res would be normal wear debris from the Master seal/bore IMHO.

    If you are keeping the slave 'o' ring in good shape then perhaps the fault is at the Master seal?
    #6
  7. RAE129

    RAE129 Adventurer

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    On a previously owned bike i had an issue with the engagement point of the clutch.

    Try opening the bleeder valve at the slave and letting all the fluid drain. Take the bleeder out and wrap the threads with teflon tape. Then inject the fluid from the slave up to the master. If you keep having issues with the engagement after you have done this, you may have an issue with the clutch master cylinder.

    I personally found it easier to drain all the fluid before injecting the new fluid. I tried bleeding using gravity and even a mityvac and i could never seem to get all the air out. It seemed like somehow, someway air got in at the slave and the clutch engagement was crapola...lol
    #7
  8. JOKER650

    JOKER650 Long timer

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    Thanks for the info and suggestions.
    I will see if I can find a junkie in the alley for a syringe...LOL:lol3
    I will give that method a try.
    Just seems really weird cuz it works fine for about a week after bleeding the damn thing.
    #8
  9. Zuber

    Zuber Zoob

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    +2 on the syringe bleed. You can try to suck it down hill, but the air bubbles just keep going up. I suck out the master cylinder first, then push the fluid in. If you were losing fluid, you can replace it without opening the master, just push it in until you can't put any more in. Takes about 5 min. on the road.

    Since you are not losing fluid, you must be sucking in air at some of the seals. The most likely place is at the master cylinder. This usually happens when you let the clutch out. I'd pull it apart and clean the heck out of it.
    #9
  10. gefr

    gefr Life is a trip

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    You may have to watch yours for signs of leak.
    Cheers.
    #10
  11. Katoom72

    Katoom72 Been here awhile

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    Get a repairkit for the master cylinder, even if it's not the culprint it's cheap and there is no harm in refreshing it.
    #11
  12. gefr

    gefr Life is a trip

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    In case this is the culprit though, the new seals will rapidly disintegrate within a month or so, operating in the damaged cylinder surface. These cylinders are colored with a hard paint. When this gets damaged, the seal gets eaten and leaks. The cylinder then needs replacement. I had good luck resleeving this with stainless steel sleeve and going down in diameter. I used lighter KTM bikes' clutch piston. The effect is holding nicely till now.
    Cheers.
    #12
  13. Katoom72

    Katoom72 Been here awhile

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    If the surface is damaged then it's a good idea to resleeve or replace the master. Thank you for correcting that. :freaky
    #13