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Hydraulic cylinder disassembly

Discussion in 'Shop Talk' started by orville, Sep 4, 2013.

  1. orville

    orville Well-Known Member

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    I have a hydraulic cylinder from a small scissor hoist that I want to rebuild. This cylinder has a different gland than what I am used to. Where you see the two long bolts, there were two short bolts that appeared to only go through the plate they were screwed into. The bolts appeared to be keeping the bolt holes clean. So I assumed if you put in longer bolts you could pull out the ring that covers the gland??? The perimeter is pretty rusty and is currently soaking with penetrating oil. Am I on the right track, or is this cylinder more complicated than I think?


    100_0911.JPG
     
  2. caterpillarmech

    caterpillarmech Senior Member

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    If I'm not mistaken, that is the type head you knock in and pull the retaining ring out. Then use the bolt to pull the head out of the barrel.
     
  3. Delmer

    Delmer Senior Member

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    I'm guessing that's right. You shouldn't need bolts in the holes to remove that ring, right?

    Again guessing, those bolts hold may hold two parts of the gland apart, I've never seen a gland that wasn't held tight, or that only had a ring to hold it firm. Don't tighten the long bolts before you loosen that ring, the bolts may put pressure on the ring upwards and keep you from tapping it down enough to loosen the ring.

    edit: yeah, what he said.
     
  4. orville

    orville Well-Known Member

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    Caterpillarmech , Delmer, I tried tapping down that ring before I put those longer bolts in. But this hoist is pretty heavy with rust. Tomorrow morning I will tap a little harder with the bolts out. In one place on the perimeter of that ring there is a indentation about one inch long (currently full of rust and dirt), might be where you get the ring out. Thanks
     
  5. caterpillarmech

    caterpillarmech Senior Member

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    The ring is like a coiled snap ring. Once you knock the head down 1/8" you should have enough room to use your pocket screwdriver to un wind it out of there. The ring is just spring steel wrapped around a little over two times.
     
  6. orville

    orville Well-Known Member

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    I am familiar with the cylinders that have holes in the gland to put a spanner wrench in to unscrew the gland. This cylinder is different.

    That ring was just one heavy ring that was one inch short of being all the way around. I had to hit the gland like I meant it to get it to go down. Once the ring was removed I had to hook a come-along to the cylinder to get the rod and gland out. The rust was terrible. I heated it once and tried to remove the gland with no luck. If I would have hooked the come-along to it the first time I could have used less heat. Thanks for the help

    Delmer if you are reading this thanks to you also


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  7. Delmer

    Delmer Senior Member

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    Thanks for posting the pic. That's a new style by me, and the coiled snap ring too, never seen one of those in a hydraulic cylinder.
     
  8. willie59

    willie59 Super Moderator

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    orville, I don't know if you've already put the cylinder back together with new seals, but if not, on those type of cylinders that have a snap ring or a spiral ring retainer for the gland you need to clean that snap ring groove real good. Over time, of cylinder stroking in/out, hitting the gland with the piston on full extension, it's not unusual for this pressure on the snap ring to create a kerf at the snap ring groove (which also causes them to be hard to disassemble). Be sure and polish the edges of the snap ring groove with emery cloth to remove this kerf, otherwise you may tear or damage a seal upon re-assembly. ;)
     
  9. orville

    orville Well-Known Member

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    I still do not have the cylinder back together. After reading your post I did take a wire brush and go around the barrel ring grove, feels pretty smooth.I did not see or feel anything out of the ordinary in the groove, but using emery cloth to put a better finish on that area sounds like a good Idea for reassembly. Thanks for the tip Willie