Backhoe questions

Printable View

  • 02-02-2019
    ki5ka
    Backhoe questions
    Hope this isn't off-topic... I prefer to get my advice here, where I know the players rather than open a conversation to a group where I don't know who is full of hot air and who knows their stuff :)

    The TLB (Tractor Loader Backhoe) I'm using is an Kubota LA852 Tractor with a 4560 backhoe. I have been unable to find a manual on-line. Wondering if anyone here can give me any leads.

    When using the backhoe, throttle about 75%, the stabilizers just barely lift the rig off the ground. When I combine inputs, often times one will stop responding until I let off on the other. Also, the speed of response is quite different.

    I'm guessing this is simply an old tired machine that hasn't been properly kept and I'm just going to have to adapt, but I'm wondering if there is any adjustment (some kind of a balancing valve) or simple maintenance that I might be able to do. It's not my machine, so this would have to be something inconspicuous and simple like bleeding the hydraulics? (maybe not simple?). It was just in for service (to get it functioning so I could use it) but I think it was more like hospice care than a full checkup.
  • 02-02-2019
    Harold
    any equipment I was ever trained to use at work, I was instructed to run the throttle at 100% when working (skid steer, mini skid steer, huge woodchipper). The throttle adjustments were always used to warm the machine up before working, or to slowly ease it down before turning it off.
  • 02-02-2019
    ki5ka
    Thanks Harold
  • 02-02-2019
    E. Bryant
    Kubota owner here. Assuming that the machine is in good condition (trans/hydro fluid at the proper level and filter changed at the proper interval), then you're probably dealing with a pressure relief valve that requires adjustment. You'll need to look up the specific process for your machine since there are a few different valves used by Kubota, but it generally involves either turning an adjustment screw or adding shims in order to increase the preload on the relief valve spring. My L3130 uses the shim method which is messier and takes longer, and it still only took my 15-20 minutes to perform the procedure the first time that I did it.

    You should have a pressure gauge + adapters in order to verify that you are achieving the specified maximum pressure, but it can be done by "feel" if you are careful and respectful of the equipment. It's easy to do damage if you adjust the relief pressure too high, so go in small steps and don't increase it any higher than required to get the equipment working properly.

    If in doubt, find a qualified shop to perform the adjustment. Parts for these things ain't cheap and broken hydraulics can make a huge mess.
  • 02-02-2019
    ki5ka
    Quote:

    Originally Posted by E. Bryant View Post
    Kubota owner here.

    Thanks for the reply E.

    Quote:

    Assuming that the machine is in good condition
    Nope, not in good condition. It's owned by the school district. I was offered a budget for my track project and asked to use some of the money to rent an excavator. The district owns this machine but it wasn't working. The Ground Supervisor suggested it would be cheaper to fix the district's machine rather than rent one for my project so that's how that all worked out. They sent it to the local shop for a pick-me-up; not sure what all was done but today the 1" main hydraulic hose sprung a leak and dumped about a quart of fluid before I noticed.

    Quote:

    ... then you're probably dealing with a pressure relief valve that requires adjustment.
    I figured there must be something along those lines. I'm hoping it's a screw. If it's more complicated than that, I'm not going to jump in. Trouble is, I need to find a manual! Really surprised I can't find one online.

    Quote:

    It's easy to do damage
    Last think I need right now is something else to go wrong LOL

    Thanks again for the reply E. Now I at least have it down to two possibilities.

    Cheers