I have a 1952 8N. I recently purchased a new Kioti 5 ft finish mower and it worked great for about 15 minutes. The lever for the hydraulics disengages and kills the PTO. I checked it running on my shop floor and after a couple of minutes it will kick it out. So i know it is not just bogging down in thick grass. The hydraulic fluid is at the full line on the dipstick. I have never ran anything on the PTO before on this tractor. I use the plow and blade regularly. The tractor has been in my possession for a few years but my grandparents bought it in '56. I know the PTO has been used not sure how recently. On a side note I changed the sludgy fluid a couple of years ago. i noticed the blade lifted a bit jerky and slower afterwards. It seems like it smoothed out after awhile. Maybe a coincidence maybe part of my issue. Any advice appreciated. thank you.