8840 Swather Head Won’t go up

During the summer I was having problems with my 8840 swather head going up once I got to the end of the field. If I played with the pressure I could eventually get it up. Had my local Case IH dealer come out they recharged it. 1200$ later it work for 30 acres. Then it wouldn’t go up at all I took it back to the barn and parked it. Need to fix it before next year. Any idea what the problem could be?

8840 Swather Head Won’t go up