1. Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!
  2. ALL NEW MEMBERS READ THIS FIRST!! Thank you for joining Heavy Equipment Forums! If you are new to forums we communicate with "Threads", please search our threads to see if your topic may have already been answered and if not then click "Post New Thread" in the appropriate forum. This will allow all of our members to see your question and give you the best chance to be answered. After you've made a number of posts you will graduate to Full Member status where you'll see a few more privileges. Following these guidelines will help make this the best resource for heavy equipment on the net. Thanks for joining us and I hope you enjoy your stay!!

8042 skytrak cylinder noise

Discussion in 'Forklifts/Telehandlers' started by bahlborn, Feb 26, 2010.

  1. bahlborn

    bahlborn Member

    Joined:
    Feb 19, 2010
    Messages:
    10
    Location:
    maryland
    Ive got a 8042 skytrak, about 9800 hours never had any cylinder work to it. The main boom cylinder that extends and retracts the boom makes a high pitch noise when in use. Would anyone know if this is a signal of a problem to come?
     
  2. Speedpup

    Speedpup Senior Member

    Joined:
    Jul 6, 2007
    Messages:
    1,214
    Occupation:
    President and all else that needs done!
    Location:
    New York
    how do you know it is the cylinder not the boom or wear pads?
     
  3. willie59

    willie59 Administrator

    Joined:
    Dec 21, 2008
    Messages:
    12,772
    Occupation:
    Service Manager
    Location:
    Knoxville TN

    Yep. 9000 + hours and no work been done to boom, wear pads may be gone. Better remove that rear boom cover and see if there are any wear pads left in there. :yup
     
  4. wildhorse trnr

    wildhorse trnr Well-Known Member

    Joined:
    Feb 13, 2010
    Messages:
    78
    Occupation:
    Field Technician
    Location:
    Texas
    If the wear pads are intact(which at 9000 hrs. are probably in need of R/R), dead head the cylinder in both directions(once the unit is warmed up) and see if you notice the noise then. Also, try it at low mid and high engine speeds. You should hear the unit bypassing at when you deadhead it.
     
  5. bcubes

    bcubes Member

    Joined:
    Jan 24, 2010
    Messages:
    7
    Location:
    Northern Illinois
    The high pitched noise you are hearing is the counterbalance (holding) valve. The high flow of oil out of the cylinder causes the valve to open and close at such a high rate it produces a squealing noise. This is normal and is not an indication of failure.
     
  6. bahlborn

    bahlborn Member

    Joined:
    Feb 19, 2010
    Messages:
    10
    Location:
    maryland
    How can i get rid of it?
     
  7. Speedpup

    Speedpup Senior Member

    Joined:
    Jul 6, 2007
    Messages:
    1,214
    Occupation:
    President and all else that needs done!
    Location:
    New York
    How come you don't hear it in other machines?
     
  8. willie59

    willie59 Administrator

    Joined:
    Dec 21, 2008
    Messages:
    12,772
    Occupation:
    Service Manager
    Location:
    Knoxville TN
    Does it make the squeel noise in both directions of telescope, in and out?
     
  9. bahlborn

    bahlborn Member

    Joined:
    Feb 19, 2010
    Messages:
    10
    Location:
    maryland
  10. willie59

    willie59 Administrator

    Joined:
    Dec 21, 2008
    Messages:
    12,772
    Occupation:
    Service Manager
    Location:
    Knoxville TN
    Hmm, man, I'm not sure. This is one I'd just about have to be there hearing what it's doing to have any good thoughts of what's going on.
     
  11. icestationzebra

    icestationzebra Senior Member

    Joined:
    Jun 21, 2009
    Messages:
    353
    Location:
    WI
    I have seen two causes for the cylinder squeal. The first cause was counterbalance valve chatter, which is really the valve opening and closing really fast. You normally notice a vibration. Not much you can do except replace the valve.

    The second cause was hydraulic oil with poor friction additives. Lull got hit with this in '91 and the remedy was to add a friction modifier to the oil. If you have never changed the hydraulic oil this may be the problem.

    I distant third would be bad cylinder seals.

    ISZ