Lag in hydraulics on zero turn; Normal?

Discussion in 'Lawn Mowing' started by Bayrat, Jul 29, 2005.

  1. Bayrat

    Bayrat LawnSite Member
    from NY
    Posts: 121

    I bought a new Gravely 260Z this spring. I love the machine, the suspension seat with back adjustment is what swayed me from other brands. I tried several brands and the choice was down to Dixie Chopper and the Gravely due to desired options and price. Gravely won based upon a better seat, a current year model and pricing. I was able to purchase the hydraulic deck lift, headlights and IQ (which is a waste of time for a homeowner) for the same dollars as a left over slightly rusty Chopper.

    Question is, I have a hydraulic lag when making fast changes/turns. It seems to occur when reversing. The Dixie Chopper dealer told me about a "buffer" in other machines due to a patented system in the Chopper. Now I, as a homeowner mowing three acres am noticing something. Is what I am experiencing normal or do I have a mechanical problem.
     
  2. lawnMaster5000

    lawnMaster5000 LawnSite Senior Member
    Posts: 589

    please describe your problem more and let me know by private message that you updated this post. I have had many problems with ny gravely hydro system and would like to be able to help you if you are having similar problems.

    Please also let me know what model year and engine you have.


    thanks
     
  3. Bayrat

    Bayrat LawnSite Member
    from NY
    Posts: 121

    Lawnmaster,

    It is a 260Z, they come with a 25HP if I am not mistaken. I will have to open the hood to confirm as it is just one of many pieces of equipment I own.

    Seems the machine has a power lag when reversing mostly. I feel I should be able to have instant response but that is not the case. For a homeowner to complain, I can imagine what a professional would be going through. These machines all use the same components for the most part, so what do you suppose would prompt this?

    I will PM you.
     
  4. TriplePLandscaping

    TriplePLandscaping LawnSite Member
    Posts: 166

    check for a loose dump valve, thats what mine had a problem with on my left hydro, wouldnt get to full power w/ it.
     
  5. Bayrat

    Bayrat LawnSite Member
    from NY
    Posts: 121

    I'll search around to see what the dump valve looks like. Not familiar with the particular part names on these.
     
  6. lawnmaniac883

    lawnmaniac883 LawnSite Silver Member
    Posts: 2,613

    Open the hood and lift the seat...you will see two hydraulic pumps. The dump valve will be a brass fitting on each of the pumps. Look in your owners manual to be sure but the dump valves should be in closed position. All you gotta do is put a wrench on the and turn the valve clockwise or until it stops. If you go to gravelys website www.gravely.com and download the manual for your 260Z on page 14 of the manual it has a picture of the valves.
     
  7. Bayrat

    Bayrat LawnSite Member
    from NY
    Posts: 121

    Thank you, I will try that this afternoon, need to mow if things dry out!
     
  8. Bayrat

    Bayrat LawnSite Member
    from NY
    Posts: 121

    I checked, they are closed. I get a bit of a lag and wheel chatter (occasionally), it is always when going from forward to reverse. I wonder if I am throttling the control too much, perhaps need just to pull all the way back more quickly. I do get quite a bit of tire spin as well, particularly when the grass is damp like tonight.
     
  9. MOturkey

    MOturkey LawnSite Silver Member
    Posts: 2,762

    Not sure if I am understanding your problem exactly, but correct me if I am wrong. By wheel "chatter", I am assuming that you mean loss of traction? Correct?

    If you are experiencing loss of traction when going from forward to reverse, the most obvious cause is simply applying power too rapidly. Moving the controls all the way back more quickly will simply exacerbate this problem. In other words, I think perhaps you are wanting instantaneous response, when in fact, you should be allowing enough time for the machine to overcome inertia when you start reversing direction. All ZTR's will break traction more easily in reverse.

    Hope this helps.
     
  10. Precision

    Precision LawnSite Silver Member
    Posts: 2,995

    what it sounds like to me is you need to get used to the machine.

    These machines are not about instant momentum changes. You can do that, but it will leave huge tear marks on your turf. These machines are to be used gracefully with subtle changes of direction and 3 point turns to reverse directions. You must always keep BOTH wheels moving.

    you may also have a leak in the return hydro lines that is allowing air in the system. this will cause mushiness. You could also have poorly adjusted levers or any number of other minor issues.
     

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