mike
Guest
If you look on this page about a month ago I asked the same question. I bought a 750 that had been sitting a few years and had the same problem. I was told to check the plastic poppet valves in the hydraulic block that is next to the hydraulic pump. However in my case, after servicing the hydraulic system and running the header up and down several times it seems to be holding. Don't know if it was a sticky valve or what. I did order the valves anyway (about $60 for all of them) If I remember right there is three valves and seats. Good luck!!