Got my Gleaner K2 out to do 10 acres of oats. Haven't had it out in a year but it started up and everything was working fine. Header & reel lifted & lowered smoothly with no hesitation or anything. I was greasing everything & doing maintenance and noticed the hydraulic oil was very low, not even showing in the sight glass with the header down. So I filled it up to the full mark & it took most of a gallon. Worked fine a few more times and then suddenly the header & reel would not lift except in very short bursts. Went back & checked the fluid level and the tank had overflowed a lot. Not sure what has happened. The header will lift all the way up eventually but only in very short bursts when you first move the lever then it stops until you release & start again. Ive done this several times thinking maybe air in the system or something but it hasn't improved. I know it has an accumulator in the system but never understood what it did or what it is for. Anyone have any insight as to what might be going on?