Hydros slipping

Discussion in 'eXmark' started by accuratelawn, Dec 6, 2001.

  1. accuratelawn

    accuratelawn LawnSite Senior Member
    Messages: 922

    I performed the end of the year repairs to my Lazer today.
    Changed the hydro fluid and replaced the ribbed belt that runs the pumps.
    Now the belt seems to slip. When the sticks are pushed forward there is a noise and delay(slight). Fluid is full and I sprayed some belt dressing on the new belt.
    Any suggestions?
  2. eXmark

    eXmark Manufacturer / Sponsor
    Messages: 4,258


    It is possible your getting belt slippage however a more likely cause would have something to do with the hydro filter change.

    First did your dealer give you an Exmark filter? Even the best parts counter personnel can from time to time pull the wrong part. Just because a filter spins on and doesn't leak doesn't mean it will work. If you've inadvertently gotten an aftermarket filter or an engine oil filter instead of a hydro filter it is possible to "starve" the pumps of oil making the unit slow and sluggish.

    Also did you pre-fill the hydro filter with oil before installing it? This is often forgotten and the most common cause for the condition your seeing. If the hydro filter is not pre-filled you can introduce excessive air into the system which could cause a sluggish reaction but could also cause an abnormally loud whining sound as well. To determine if you have air in the system you can run the unit for a few minutes the shut it off and look into the hydro reservoir with a flashlight. If the fluid is milky or gold in color you've got an air ingestion problem. If that is the case, make sure the filter is tight and go for a ride. It will take some time but the hydros should purge out the air after 30 - 40 minutes. Incidentally the way the valving is set up in the Lazer you can actually purge the air from the system faster in reverse than forward. If you have a set of jack stands and a large open area on a hard surface you can place the rear of the unit on jack stands. Be certain to block the front tires, open the pump wheel release valves a ¼ turn (don’t open farther than ¼ turn) and run the unit that way for 20-30 minutes as well. You may want to strap the unit in place as well just in case your jack stands fail.

    If the above suggestions do not resolve the sluggish reaction take the unit to your local Exmark dealer.

    Let me know what you find out.


  3. Kent Lawns

    Kent Lawns LawnSite Senior Member
    from Midwest
    Messages: 870

    The short answer:

    You got air in your hydro system.

    To correct: Run forward in a straight line for a few hundred feet.

    (I know I don't carry the authority of eXmark, but I've encountered this several times.)
  4. eXmark

    eXmark Manufacturer / Sponsor
    Messages: 4,258

    I agree,

    The air in the system is where the noise is coming it will cause pausing or sluggish feel at the sticks.

    One more thing that I would like to add is check your reservoir to ensure that it is full after all the air is out. Cold it should be just below the center baffle (1/8"). Hot it will be over the baffle (1/8").

    Thanks, Fred.
  5. accuratelawn

    accuratelawn LawnSite Senior Member
    Messages: 922

    Thanks for the help.
    In the past after changing fluid only a few minutes were needed to purge the air from the system. I mowed my entire lawn (3 acres) and had the mower on a jack for another 5 minutes. After all that there was still air in the system.
    I put it back on the jack and ran it in reverse for about 10 minutes.... Problem corrected.

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