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  1. #1
    Gold Member
    Join Date
    Jun 2001
    Posts
    251
    Location
    SE Michigan
    Tractor
    John Deere 4300 HST

    Default Hydraulic Question

    Over the weekend, I was using the FEL to lift shingles to the roof of my new chicken coop. I noticed that the bucket lowered on it's own with the tractor both running and not running. The bucket was over the roof, and gradually dropped enough to crush the corner of the roof it was over.

    Is this normal? I guess I could see it dropping with the tractor off, but with it running? It only dropped 2-3 inches, but that was because the building was supporting it after that.


  2. #2
    Epic Contributor Bird's Avatar
    Join Date
    Mar 2000
    Posts
    37,729
    Location
    Texas

    Default Re: Hydraulic Question

    A very small amount of drop may be considered normal, but it sounds to me like yours has too much drop. There can be one or more of several causes. When you moved the joystick around to operate the loader and came back to the middle or neutral position, if something was just a tiny bit sticky it may not have exactly centered; try wiggling it around a little and see whether that solves the problem. Otherwise, you either have a slight internal leak in the valve, or in the cylinders, that's letting the fluid by. I'm assuming you don't have a visible external leak, of course.


  3. #3
    Gold Member
    Join Date
    Jun 2001
    Posts
    251
    Location
    SE Michigan
    Tractor
    John Deere 4300 HST

    Default Re: Hydraulic Question

    Nothing I could see. I left the bucket up, went up on the roof, worked for a few minutes, then noticed the bucket had dropped. Probably 4 inches max. Does it matter if running or not?


  4. #4

    Default Re: Hydraulic Question


    John Deere Technical Notes

    Loader and backhoe boom/bucket lower slowly while parked

    Symptoms
    What is normal leak down for the Selective Control Valve (SCV)?

    Situation or Problem
    No publication specifies a procedure or allowable specification.

    Summary
    Step One
    Place the backhoe or loader boom cylinder in the half-extended position with bucket empty.

    Step Two
    Measure the amount of rod extending from the cylinder.

    Step Three
    Allow the implement to sit undisturbed for 30 minutes.

    Step Four
    Measure the amount of rod that extends from the cylinder again.

    Step Five
    If the rod movement exceeds the maximum allowable travel listed in the charts below, determine if the SCV or the cylinder is leaking excessively by:

    Stroke the valve to extend the cylinder to full stroke.

    CAUTION: To avoid possible injury, support the implement before hose removal. Unexpected movement of the implement could occur and result in serious injury, if the wrong hose is disconnected. Make sure the return line is the one being removed. This is the line at the cylinder's rod end when the cylinder is extended. Avoid oil penetration injury when observing for cylinder leakage.

    Remove the return hose from the cylinder.

    Stroke the valve in the extend direction again.

    If oil comes out of the disconnected cylinder fitting, the cylinder is leaking.

    If oil does not come out of the disconnected cylinder fitting, the valve is leaking.

    Maximum Allowable Travel 410 Loader Lift cylinder, 191 mm (7.5 in.) / hour
    410 Loader Bucket cylinder, 313 mm (12.3 in.) / hour
    420 Loader Lift cylinder, 150 mm (5.9 in.) / hour
    420 Loader Bucket cylinder, 218 mm (8.6 in.) / hour
    430 Loader Lift cylinder, 117 mm (4.6 in.) / hour
    430 Loader Bucket cylinder, 219 mm (8.6 in.) / hour
    440 Loader Lift cylinder, 150 mm (5.9 in.) / hour
    440 Loader Bucket cylinder, 218 mm (8.6 in.) / hour
    460 Loader Lift cylinder, 965 mm (3.8 in.) / hour
    460 Loader Bucket cylinder, 145 mm (5.7 in.) / hour
    47 Backhoe Lift cylinder, 15 mm (0.6 in.) / minute
    47 Backhoe Stabilizer cylinder, 8 mm (0.3 in.) / minute
    47 Backhoe Stabilizer cylinder (retract rate), 5 mm (0.2 in.) / minute
    48 Backhoe Lift cylinder, 10 mm (0.4 in.) / minute
    48 Backhoe Stabilizer cylinder, 5 mm (0.2 in.) / minute
    48 Backhoe Stabilizer cylinder (retract rate), 5 mm (0.2 in.) / minute

    Additional Information
    When disconnecting the return hose from the cylinder to determine leakage of the cylinder or SCV on a loader, both cylinders' returns are tied together. If leakage is observed from the disconnected cylinder, that cylinder is leaking. If leakage is observed from the hose, the opposite cylinder is leaking.

    Affected Equipment Model: 790
    Model: 990
    Model: 4100
    Model: 4200
    Model: 4300
    Model: 4400
    Model: 4500
    Model: 4600
    Model: 4700
    Model: 410 Loader
    Model: 420 Loader
    Model: 430 Loader
    Model: 440 Loader
    Model: 47 Backhoe
    Model: 48 Backhoe
    _________________






  5. #5
    Epic Contributor Bird's Avatar
    Join Date
    Mar 2000
    Posts
    37,729
    Location
    Texas

    Default Re: Hydraulic Question

    Wow, John gave you lots of details, but I don't see whether it mentions tractor engine running vs. not running.[img]/w3tcompact/icons/wink.gif[/img] When I had cylinder seals leaking, though, my front end loader would gradually lower regardless of whether the engine was running or not.


  6. #6
    Elite Member
    Join Date
    Mar 2000
    Posts
    3,239
    Location
    Eastern Virginia
    Tractor
    EarthForce EF-5 mini-TLB (2001)

    Default Re: Hydraulic Question

    As Bird indicated, it should make absolutely no difference whether the engine is running or not. If it does vary depending on whether the engine is running, you've got something really strange going on, most likely paranormal... [img]/w3tcompact/icons/smile.gif[/img] (Though it is remotely possible that an internal valve leak could be affected slightly by the engine running, but highly unlikely.)

    MarkC

  7. #7
    Gold Member
    Join Date
    Jun 2001
    Posts
    251
    Location
    SE Michigan
    Tractor
    John Deere 4300 HST

    Default Re: Hydraulic Question

    I would have to say John's post answered my question. I would have to be awfully close to fitting into the spec on the chart. Thank-you everyone for your help.

    With the tractor being new, and me being new to anything involving hydraulics's, I had to ask. It's nice having "normal" defined for the travel on the FEL's and hoe's.




  8. #8

    Join Date
    Oct 2000
    Posts
    291
    Location
    s.e.okla.
    Tractor
    4200 hst

    Default Re: Hydraulic Question

    Ol-Big John is slicker than goose poop fer sure!
    Deere man ta boot!


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