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  1. #1
    Silver Member
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    May 2007
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    121
    Tractor
    NH TC 55 DA

    Default Grapple top forks the pressure won't release

    Sorry to bother all of you again with this dilema, but many of you helped me on this issue a few months ago and I have one follow up question.

    The rear remote lines which flow into the top forks won't release pressure after I turn tractor off. All the FEL hydraulics release but the forks stay put even if I move the slide lever back and forth (tractor off) Now when the tractor is started the forks are working great, but here's the dilema.

    When trying to disconnect the "quick" disconnects up front they are NOT bleeding the pressure off those lines. Roy you told me how to cover the ball with cloth and tap the pressure off and also push the pin gently on female which was a great help as I reconnected grapple this weekend, but taking
    the grapple OFF I have the same trouble. If the slide lever is not releasing
    rear remote pressure is there some other valve that will do that..?

    Is rear remote pressure different than FEL pressure..? This is NH TC 55 DA

    Thanks again. Bill

  2. #2
    Advertiser kennyd's Avatar
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    Jul 2003
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    Westminster, MD
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    John Deere 4110, 455

    Default Re: Grapple top forks the pressure won't release

    I am unclear as to what the "slide lever" is?
    Is this an electrical control? If it's electrical, then the key might have to be ON so the electric valve can operate.
    If it's a mechanical lever that operates the rear remote, then it's makes no sense why it would not release pressure with the tractor OFF
    KennyD
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  3. #3
    Super Star Member J_J's Avatar
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    Sep 2003
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    JACKSONVILLE, FL
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    Power-Trac 1445, KUBOTA B-9200HST

    Default Re: Grapple top forks the pressure won't release

    Quote Originally Posted by millpond
    Sorry to bother all of you again with this dilema, but many of you helped me on this issue a few months ago and I have one follow up question.

    The rear remote lines which flow into the top forks won't release pressure after I turn tractor off. All the FEL hydraulics release but the forks stay put even if I move the slide lever back and forth (tractor off) Now when the tractor is started the forks are working great, but here's the dilema.

    When trying to disconnect the "quick" disconnects up front they are NOT bleeding the pressure off those lines. Roy you told me how to cover the ball with cloth and tap the pressure off and also push the pin gently on female which was a great help as I reconnected grapple this weekend, but taking
    the grapple OFF I have the same trouble. If the slide lever is not releasing
    rear remote pressure is there some other valve that will do that..?

    Is rear remote pressure different than FEL pressure..? This is NH TC 55 DA

    Thanks again. Bill
    By saying slide lever, are you talking about the barrel on the quick disconnect. If it is, sometimes those springs are a little to hard to compress. Also, on some disconnects, the barrel locks in one position, and you have to turn the barrel to pull back. Another thing, if the forks or whatever is putting reverse pressure on the disconnects, it might be difficult to release. It might also have to do with something called load checks, which keep the hydraulic fluid from draining off.
    J.J.

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

    Git er done.

  4. #4
    Super Star Member J_J's Avatar
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    Sep 2003
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    JACKSONVILLE, FL
    Tractor
    Power-Trac 1445, KUBOTA B-9200HST

    Default Re: Grapple top forks the pressure won't release

    Maybe you could take advantage of the flat face couplings that can be connected and disconnected under pressure.
    J.J.

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

    Git er done.

  5. #5
    Platinum Member
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    May 2004
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    882
    Location
    Harpers Ferry WV
    Tractor
    Kubota L4330, 6 rear remotes

    Default Re: Grapple top forks the pressure won't release

    This is a grapple you are trying to disconnect? ...If so, the grapple has to be "closed" all the way ...otherwise gravity is pulling down the grapple, putting pressure on the hydraulic cylinder and pressurizing the line. Letting the jaws fully close, or close on a block, or using a bottle jack to push it up slightly might help, if I understand the problem you are having.

  6. #6
    Silver Member
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    May 2007
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    121
    Tractor
    NH TC 55 DA

    Default Re: Grapple top forks the pressure won't release

    The slide/lever is located on right side of drivers seat. It is the open/close function for rear remote. On TC 55 DA at least. It's not something that I needed to add for grapple use. It sounds like I need to close grapple while tractor is on to relieve the fork pressure, I thought the actual weight of forks
    like on FEL would bleed the pressure off those forks..ie slide the lever back and forth like you would with joystick on FEL. Sounds like the bleed on quick disconnects is simply close forks all the way down before turning tractor off..
    Island Tractor you have Millonzi how do you bleed fork pressure..?

  7. #7
    Platinum Member bjcsc's Avatar
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    Feb 2007
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    559
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    Johns Island, SC
    Tractor
    JD 5225, JD 555B

    Default Re: Grapple top forks the pressure won't release

    Although I'm not sure I understand what you mean by slide lever, I'll take a shot. Is it a lever that diverts your rear remote, i.e. splits the function? Your grapple is connected to a rear SCV, right? Is it electric? Is it the same lever that operates everything that you connect to the SCV? My thumb button on my stick performs the same function, but since it's electric the ignition has to be on. I close my grapple, shut down, turn the ignition on and cycle the valve...

  8. #8
    Silver Member
    Join Date
    May 2007
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    121
    Tractor
    NH TC 55 DA

    Default Re: Grapple top forks the pressure won't release

    BJCSC..Thanks for the note. The lever is indeed an open and close tied into rear remotes. On NH TC 55 DA this lever is below the drivers seat. I don't believe it is electric. Let me see if I can describe the issue again. This lever is like PTO engage lever, however when you move it forward the forks open and when you slide lever back the forks close.(technically I could switch the lines in rear and the lever would move the forks the other way) When shutting down the engine I can bleed all hydraulic pressure away from boom/curl/lift etc, but the lines just from rear remote to the dual forks on top of grapple will NOT release its pressure. That's after I've shut engine down and slide lever back and forth. This leads to two problems. The "quick disconnects" are hard to remove and when reattaching the the grapple I need to manually tap the lines from the grapple before I can reattach grapple.
    This can't be right I hope..? Or am I going to get pressure release by closing those forks all the way down and then turn engine off..?

  9. #9
    Veteran Member 6sunset6's Avatar
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    May 2007
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    1,001
    Location
    SE NY
    Tractor
    NH TC34DA 34HP HST, 2 rear remotes, front diverter, loaded R4's, MF 30 TLB

    Default Re: Grapple top forks the pressure won't release

    I think lower the grapple all the way down and then jiggle the valve a little bit and leave it down. That should do it I think.
    The equiv to this would be like trying to disconnect a hydraulic top link while the 3pt was up in the air with an implement on it. If you have a hyd top link.
    Bob H
    NH 2007 TC34DA 1985 MF30E Hoe

  10. #10
    Platinum Member
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    Dec 2006
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    705
    Location
    Columbus, Georgia
    Tractor
    Kuborta B2400, L2900, L4330; Caterpillar D3B, John Deere 455D

    Default Re: Grapple top forks the pressure won't release

    Your remote valve probably has pilot operated load checks to prevent a cylinder from moving unless the pump pressure exceeds (by a few pounds) the cylinder pressure. IF the engine is off there is no pressure to open the load check, so moving the valve alone will not allow fluid to flow out of the cylinder. If the weight pushing the cylinder to move (ie, weight of the grapple) is enough to create enough of a vacuum in the circuit that the pressure differential exceeds the cracking pressure of the check valve, the cylinder will usually slowly move.

    But usually with load checks the pressure does bleed off one of the lines: the one with no pressure on it from the cylinder (the base end line when the grapple is open). Check and see if one of your lines does release the pressure: stop the engine with the grapple open, work the lever back and forth, and see if the line to the base end of the cylinder will disconnect. Depending on what you find out we will work on the next step.

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