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Genie Z45/22 Torque hub leaking hydraulic fluid(crack in housing)

Discussion in 'Forklifts/Telehandlers' started by mr hatt, Nov 19, 2020.

  1. mr hatt

    mr hatt Member

    Joined:
    Mar 17, 2017
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    Location:
    south central kentucky
    I just bought a used z45/22 boom lift and have fluid leaking from one of the drive hubs. Looking at it closer I see a small crack in the cover and fluid appears to be laking around the sealing surface as well. I am thinking that the brake assembly must have a bad seal and that the hydraulic fluid is bypassing the seal and entering the torque hub.
    Can somebody let me know if they think I'm on the right track?

    If it was the drive motor leaking I would think that hydraulic fluid would be coming out the back side where the drive motor mates up to the brake housing.

    Any advice is appreciated.
     
  2. Txhayseed

    Txhayseed Well-Known Member

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    They are a wet hub. There should be fluid. I would just order a new cover and o ring if it’s cracked.install it add fluid and roll
     
  3. mr hatt

    mr hatt Member

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    The fluid in and coming out of the hub is dextron. Not the best lubrication for a torque hub, but i've seen worse. I strongly suspect that the brake mechanism is allowing fluid to bypass into the hub. If I don't fix the incoming hydraulic fluid I think the hub cover will either crack again or leak around the sealed surface. Just my theory from looking at this for a few hours.
     
  4. skata

    skata Senior Member

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    You're thinking the cover cracked because of an internal leak? If it had that much pressure to crack the housing, then fluid would probably be pouring out while trying to drive.
    Did anyone tow or pull the machine recently?
     
    DB2 likes this.
  5. mr hatt

    mr hatt Member

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    I just got the machine, but I have no reason to think that it was towed recently. The brake mechanism looks like it it a simple hydraulic piston type with springs apply the brake when fluid pressure is not present. It will weep while the machine is just idling. When moving it seems to leak more, but I really can't watch it and drive at the same time.

    I think that if it were a drive motor it would leak out of the back side of the brake assembly. I don't see how it could get through to the hub that way. So that is what led me to the brake leaking fluid around the piston and into the hub. I came across a video showing a guy rebuilding this same style of brake. Just a couple of oranges to seal the pressure.

    I know a lot of people on this forum will have more experience with these lifts than I do so that's why i thought I would ask. Thank you for helping me sort this out.
     
  6. skata

    skata Senior Member

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    Go to genies website and download the manuals for this machine, and see how the drives are set up.
     
  7. mr hatt

    mr hatt Member

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    First thing I did was to get the service manual for this machine. It shown no explode view of the assembly. I have contacted my local dealer to check on part availability and am waiting for them to get back with me.
     
  8. Txhayseed

    Txhayseed Well-Known Member

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    Does your cover have two plugs ? They do not have enough pressure to crack the cover. Unless your hydraulic tank was filled with dextron also you would also see hydraulic fluid if you where bypassing a seal since the brake pulls it’s supply from the traction control manifold. A lot of people atf in the outer hub since they can poor it from a bottle through the fill plug with a small funnel.
     
  9. DB2

    DB2 Senior Member

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    Before I was qualified I broke a torque hub cover when I was trying to reassemble it on the machine. Seems they go together easier when they are horizontal as opposed to vertical. I tried to pull it it together with the bolts. Lesson learned the hard way $$$
     
  10. mr hatt

    mr hatt Member

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    The cover has 2 plugs on the side of the housing not on the face. The crack is about 1.5" by the square tag. As soon as I start the machine it is lightly weeping. So there as absolutely hydraulic pressure being pushed into the housing. I believe the brakes are supposed to get 350# of pressure and I have read on here about another unit that would spike to 1000psi when they measured it. So i could see that cracking a large aluminum housing. The final drives I have worked on were not rated for much pressure. I wouldn't think that those torque hubs would be rated to 350#.
     
    DB2 likes this.
  11. skata

    skata Senior Member

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    Well. If it were me, I'd start taking the planetaries apart. Verify the pump is leaking. Then look on pump for part numbers. Maybe the pump just needs new seals...
     
  12. Txhayseed

    Txhayseed Well-Known Member

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    I’m like skata pull the cover let it drain. Not going to hurt to let the planetary to run try for a few just to test it if you think it’s passing through the seal. If it’s by passing you should see that right away. Put a gauge on the PBTP port and see what your getting. Sounds like your pretty convinced it’s bad so why not just order the parts and fix it.
     
  13. mr hatt

    mr hatt Member

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    Taking the planetary apart would only tell me what I already know. Hydraulic pressure is getting into it. My primary question was has anybody seen this before and is this common.

    In the absence of that information I blocked off the line going to the brake assembly. Started the machine, and still had fluid pushing out of the brake assembly port. I then loosened up the drive assembly and found fluid coming from there. Looks like the drive will at least need new seals. I'll send it to hrt in Western Kentucky next week.
    The fact that it was pushing hydraulic fluid through the brake assembly tells me I probably have a seal problem there as well.

    I called my local genie (MH Equipment) in Bowling Green ky to inquire about parts availability and pricing on thursday. Hopefully I will hear something back this next week.

    I am surprised that fluid was pushing through the drive with the machine idling. I would normally thing that with the unit idling and no functions engaged that there would be no fluid going to the drive motor. In any case the seals should hold operating pressure and at some point hit a relief valve pressure.
     
  14. lantraxco

    lantraxco Senior Member

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    Motor probably has a counterbalance valve, control valve will have an open center spool, so tank pressure, or return manifold pressure, may be constantly present at the motor ports, may also have makeup checks which would allow that small amount of pressure to be present on into the motor case and out through a bad shaft seal, or brake shaft seal.