How to change Hydro Fluid in Scag??

Discussion in 'Mechanic and Repair' started by FatherandSon, Feb 3, 2003.

  1. FatherandSon

    FatherandSon LawnSite Member
    Posts: 70

    We have two Scag Turf Tigers, 2001 and 2002. Over the winter I am doing the maintenance on them. I have never changed Hydro Fluid and hate to admit it but am very limited in my mechanical ability.

    Could someone advise how is the best way to change the Hydro fluid in these machines. Trying to save some money on labor costs but am scared on messing up.

    Thank you for your help.
     
  2. Mr.Wrench

    Mr.Wrench LawnSite Member
    from N.H.
    Posts: 65

    Well, here is the way that the factory reps tell us to deal with hydro servicing. First of all do not drain the whole system. Take your hydro filter off and let it drain, with the cap off of the hydro reservoir. Replace the Hydro filter with an "Original Equipment" filter! Do not use an aftermarket filter! Fill the filter as much as you can with the recommended oil before installing it, this will limit the amount of air that gets into the system. Fill the reservoir to the recommended level. Jack up the rear of the machine till the rear drive wheels are off the ground (using a jack suited for the job). Be sure to block the front wheels so the machine will not roll. Start the machine and work the levers foward and reverse till both wheels respond without hestitation. This procedure will help bleed the air from the system. Shut machine off, lower machine, Check hydro fluid reservoir again for proper fluid level, check for leaks around hydro filter. Now you should be good to go.
    The reason manufactures do not want you draining to whole system is because ie, removing all the hoses etc, is because of possible contamination of the wheel motors and pumps. If you change your hydro fluid and filter regularly you should not have any hydro problems, that is unless the workers like to slam the machine into reverse while going foward full speed, or like doing donuts on the asphault parking lot. Hopefully this does not apply. Hope all this info helps.:D
     
  3. FatherandSon

    FatherandSon LawnSite Member
    Posts: 70

    Mr. Wrench,

    Thank you so very much for your detailed instructions. I have printed them out and will use them faithfully. People like you make this site GREAT...

    This will be my first year chaning them and I really had no idea except what the manual said.

    Thanks again. By the way I am a Old time, 1965, Patriots fan, season ticket holder, and have a daughter that lives in Manchester.

    Your help is greatly appreciated.

    Don Montross, Sr.
    dgmontross@blast.net
     
  4. PR0 TURF

    PR0 TURF LawnSite Bronze Member
    Posts: 1,089

    I have a 1999 Scag hydro 48"w/b. My question is does anyone know the "recommended fluid" to put back into the hydro system. I do not have the manual. I've heard reagular hydraulic fluid and also have heard 10w-30? I know i can just call the dealer on Monday but I am hoping to finish this up tommorow (sunday). Thanks for your input
     
  5. Mr.Wrench

    Mr.Wrench LawnSite Member
    from N.H.
    Posts: 65

    Most of the new Hydro systems use Mobil 1 synthetic oil. Exmark and Walker use Mobil 1 15w50. I would however check with the manufacture to verify the correct oil to use. Using the wrong oil and filter can turn your hydro pump and motor into a pile metal filings.
     
  6. Mr.Wrench

    Mr.Wrench LawnSite Member
    from N.H.
    Posts: 65

    Happy to help Don, I'm originally from NY, but I still like the PATS.
     
  7. yardman1

    yardman1 LawnSite Senior Member
    Posts: 458

    Change it the way Mr.wrench to, he explained it alot better then I could.

    Pro Turf, most of scag w/b use 10w-30 and turf tigers use 20w-50, I went to 15w- 40 (i think)Mobil 1.
     
  8. yardape

    yardape LawnSite Member
    from usa
    Posts: 2

    I changed mine by removing the plug in the bottom of the tank, replacing the filter, filling up the tank, and starting. The machine made a some noise and would not move. I just let it idle for a while and slowly worked the handles until it responded. Do you think that I have damaged the machine? I am running amsoil seires 2000 20/50 synthetic oil.
     
  9. Mr.Wrench

    Mr.Wrench LawnSite Member
    from N.H.
    Posts: 65

    I don't think you did any damage to the machine. Be sure to use the oil recommended by the manufacture. Mobil 1 synthetic seems to be working the best. The object in servicing a hydro system is to keep as much air out as possible. Reason being is that when air enters the pump it can produce what is called Cavitation. Cavitation is the displacement of the oil by air, now instead of oil lubricating a pump running at full speed, there are air pockets as well (metal on metal) this can lead to premature wear on the pump plate and the pistons. The non responsive controls that you mentioned are typical. It takes a minute or two to get the air out of the loop (at idle only!)
    Josh
     
  10. yardape

    yardape LawnSite Member
    from usa
    Posts: 2

    Thanks for putting my mind at rest.

    Rich
     

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