Help on Gravely Hydraulic lift

Discussion in 'Mechanic and Repair' started by Psycho Clipper, Jun 19, 2008.

  1. Psycho Clipper

    Psycho Clipper LawnSite Member
    Messages: 8

    Can anyone offer any ideas as to what to do? I have a Gravely Promaster 148Z with hydraulic lift. I recently changed the hydraulic fluid and filter, and have been having problems since. Yes, I used the correct oil - 15w-50 synthetic. I bled the lines, yet I still get a sluggish lift. Lately, I can't get it past 4 in. height. I blew out all the lines. The lift lever doesn't stick. It drives just fine, so I figure the pumps are good. Also, the fluid hasn't gone down at all. I changed out about 2 months ago. There is no info on this problem that I can find in the forums, or the net.

    Thanks for your help.
  2. John Gamba

    John Gamba LawnSite Fanatic
    from ct
    Messages: 10,812

    It sounds air bound???Bleed the line after the lift cylinder.thats what i would try if gravely did know what to after you call them.
  3. GravelyNut

    GravelyNut LawnSite Bronze Member
    Messages: 1,594

    Like John said, sounds like it is air bound. IIRC, the lift side of the ram is lower than the rest of the ram. That traps air in the cylinder. You might have to fill the cylinder with the ram retracted fully using a pump oil can thru the fitting for the hose. The high pressure end is the rod end and that is the lift end.

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