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  1. #1
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    Trouble removing hydr damper from '98 Marzocchi Z2 Bomber

    I've removed the fork legs from the crown and removed the top plugs and springs. Then I unscrewed the 15mm foot nut from the left leg, separated the stanchion and slider, and removed the pumping element. All's good so far. But now when I try to unscrew the 15mm nut from the right leg to remove the damping cartridge, it seems that the damping cartridge is just spinning in the slider. I cannot figure how to secure that cartridge down inside the slider sufficiently to get the 15mm foot nut off. Any ideas? Am I doing something wrong?

    Ultimately, I'm trying to replace seals as I was getting oil leakage out the top of the sliders.

  2. #2
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    I think the damping cartridges have 4 notches around the top.
    I got a piece of PVC pipe of the right diameter and shaped the end to catch the notches so I could use the pipe to stop the cartridge spinning.
    The pumping rod (at least the ones in my '99 Z3) don't have the notches. I was able to get them out but had a heck of a time getting them back in as the rod would just spin.

    The illustration in the Marzocchi manual shows the foot nut being tightened with a torque wrench which was exactly what I was trying to do. I contacted them to see how they got around the problem of the pumping rod spinning and they said they just used a specially calibrated impact wrench at the factory.

    I ended up carving the same notches in the top of the pumping rod as were already there in the top of the damping cartridge and using the pipe.

    So yeah, that's how I got them out, have fun getting them back in too!

  3. #3
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    You're doing everything correctly. What you need is the proper tool, which in this case is an impact wrench. An impact wrench can spin the bolt much more quickly than the cartridge can spin inside the sliders.

    Another possibility, but don't hold me to this one as I don't own a 98 Z2...reinstall the spring into the right leg and install the cap then compress the right leg of the fork while trying to undo the retaining bolt. In doing so, you're hopefully exerting pressure on the cartridge to keep it from rotating while you're trying to undo the retaining bolt.
    Go on ahead, I'm gonna take a breather.

  4. #4
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    Thanks to winter and surestick. I actually thought about a tool also to catch that 4-notched thing down inside so I made one up out of a copper pipe, sounds like the same idea as your pvc pipe. But that didn't work either, it seems that 4-notched thing is just a sleeve that the damper cartridge sits inside of? Not sure of that obviously cuz I don't have it apart yet, but when I used my copper pipe tool, and I'm pretty sure it was catching those notches, the nut still just spun.

    I also tried the idea of reassembling the spring and cap to load up the cartridge with some axial force, that didn't work either.

    The impact wrench sounds like a good idea. I don't have one, but maybe I can find a friend who does. That fork has never been taken apart in 10 years so it could be that the threads have some corrosion that is holding on tightly.

    Any other ideas / suggestions are welcome. Thanks for the responses. - Dave

    oh yeah - by impact wrench - are you referring to a compressed air tool type, or one you use with a hammer?

  5. #5
    Elitest thrill junkie
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    I fought the impact wrench thing for a long time and finally gave in a few weeks back. Even though I have a TINY air-compressor I only use for filling up tires, it is plenty adequate for installnig/removing footnuts with an impact wrench. As much as you try, sometimes you just can not get it tight/loosen it.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

    You're turning black metallic.

  6. #6
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    so your small air impact wrench did the trick?

  7. #7
    PMK
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    Install the spring and cap, Compess the fork as much as possible and tie it there. Then spin the nut free.

    Since working on the Marzocchis since 1997, I don't recall ever needing to zip one apart.

    The nut and cartridge threads are both aluminum, if they have galled, the impact will just snap the cartridge. By hand you may get it apart with a clockwise / anti clockwise series of movements.

    PK

  8. #8
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    OK, I'm going to go try that right now. I'll let you know how it goes. Thanks.

  9. #9
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    Darn, that nut still does not unscrew. I put the spring and cap back on, full preload, then compressed it all the way, secured it there. That nut is still not unscrewing! I don't want to give it a rap since the threads are just aluminum. Maybe I'll soak it with WD40 overnite from the bottom and try it again tomorrow.

  10. #10
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    What would you think of a little heat applied to the nut, judiciously with a propane torch?

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