Results 1 to 7 of 7
  1. #1
    Bronze Member
    Join Date
    Jan 2009
    Posts
    53

    Default NH TN75 hydraulic pump whining

    So after checking the hydraulic oil the other day and noticing that it appeared to be a diifferent color (level was ok) changed the oil and filter out and it is now whining pretty loud at start up...everything works, loader, 3pt...and after about 20 secs the whining noise stops. It was not doing this before and I had only noticed a whine at start up when it's really cold (it was 95 today)... And thoughts? Bout to do some googling and go back to the manual...

  2. #2
    Veteran Member Jerry/MT's Avatar
    Join Date
    Feb 2008
    Posts
    2,001
    Location
    Western Montana
    Tractor
    New Holland TD95D, Ford 4610 & Ferguson TO-30

    Default Re: NH TN75 hydraulic pump whining

    Pumps will whine when they entrain fluid and air. It sounds like you pump is sucking some air in at start up and once it clears the air it's running quiet. Did you fill it to the proper level?

  3. #3
    Platinum Member DieselMonk's Avatar
    Join Date
    Dec 2004
    Posts
    586
    Location
    Nova Scotia
    Tractor
    New Holland / T4.75 Powerstar & Boomer 1030, Case 580 SM II

    Default Re: NH TN75 hydraulic pump whining

    It took me a few engine hours, after the hydraulic oil change, for everything to quiet down as it was. My guess is when you pull the dipstick, it is fll of little air bubbles.

  4. #4
    Bronze Member
    Join Date
    Jan 2009
    Posts
    53

    Default Re: NH TN75 hydraulic pump whining

    It didnt do it as bad last night - but still for a good 15 seconds or more....I was told to leave the cylinders extended and let them seep down by themselves and this would help to get rid of any possible air in the lines -- we'll see
    thx

  5. #5
    Super Star Member J_J's Avatar
    Join Date
    Sep 2003
    Posts
    16,725
    Location
    JACKSONVILLE, FL
    Tractor
    Power-Trac 1445, KUBOTA B-9200HST

    Default Re: NH TN75 hydraulic pump whining

    The whine you hear might be cavitation caused by a suction leak or suction restriction. You din't want to hear that noise for a long time, as the bursting bubbles can erode parts of the pump.

    Re-tighten all clamps on the suction hose.

    You could try oil or grease on all the possible air entry points.

    Other noise sources.

    http://en.wikibooks.org/wiki/Acousti...raulic_Systems
    Last edited by J_J; 06-26-2012 at 09:50 AM.
    J.J.

    When I works, I works hard. When I sits and thinks, I goes to sleep.

    Git er done.

  6. #6
    Bronze Member
    Join Date
    Jan 2009
    Posts
    53

    Default Re: NH TN75 hydraulic pump whining

    Quote Originally Posted by J_J View Post
    The whine you hear might be cavitation caused by a suction leak or suction restriction. You din't want to hear that noise for a long time, as the bursting bubbles can erode parts of the pump.

    Re-tighten all clamps on the suction hose.


    You could try oil or grease on all the possible air entry points.

    Other noise sources.

    Acoustics/Noise in Hydraulic Systems - Wikibooks, open books for an open world
    You make one comment there about bubbles - could quality of oil cause more bubbles than others? Or is it more quality/condition of hydraulic system?
    Thx

  7. #7
    Super Star Member J_J's Avatar
    Join Date
    Sep 2003
    Posts
    16,725
    Location
    JACKSONVILLE, FL
    Tractor
    Power-Trac 1445, KUBOTA B-9200HST

    Default Re: NH TN75 hydraulic pump whining

    I am pretty sure the density of the fluid will have something to do with the onset of bubbles.

    The cavitation is caused by something breaking the vapor barrier of the fluid.

    Is propeller cavitation, it is the propeller forcing itself through the water at a certain speed and depth that will cause cavitation.
    J.J.

    When I works, I works hard. When I sits and thinks, I goes to sleep.

    Git er done.

Similar Threads

  1. TN75 Hydraulic Leak at 3pt and resevoir
    By ezslim in forum New Holland Owning/Operating
    Replies: 25
    Last Post: 09-11-2012, 07:58 PM
  2. Replies: 3
    Last Post: 05-29-2010, 05:47 PM
  3. Brake Problem / Hydraulic Pump Assy. on TN75
    By 1bush2hog in forum New Holland Owning/Operating
    Replies: 0
    Last Post: 06-14-2007, 10:13 AM
  4. hydraulic pump shimming to increase/restore pump
    By kellytheaker in forum John Deere Owning/Operating
    Replies: 6
    Last Post: 03-28-2006, 09:22 PM
  5. TN75 Hydraulic Performance Question
    By TN75Jason in forum New Holland Owning/Operating
    Replies: 3
    Last Post: 12-20-2005, 11:39 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
© 2014 TractorByNet.com. TractorByNet is a registered trademark of IMC Digital Universe, Inc. Other trademarks on this page are the property of their respective owners.