Tractor....1952 Late Model side distributor. Hydraulic oil changed last year. 75W90
I have been using it the past couple of days and everything was AOK. Today I raised the disk up off the ground while I replaced a bolt and spacer in the disk. I left the tractor running while I did the job. When finished I tried but could not raise or lower the disk. Lunch time, so I turned the tractor off and left the disk to leak down on it's own. As I was having lunch nearby I heard what sounded like something had released. I went back, started tractor, and everything worked as it should. Wanting to be pro-active I thought I might ask here if anyone has an idea what might be wrong?