'78 222. I was out spreading some gravel a few weeks ago with the plow on the front of my 222. I was dropping it down far enough just to take the weight of the tractor off of the front wheels. I could drive around and it would hold that position without any problem. Unfortunately I hit a big rock in the ground and the blade caught, lifting the tractor up in the air pretty high, likely over-stroking the cylinder. After that, the hydraulics wouldn't hold. I'd drive the blade to the ground and it would lift the tractor, but as soon as i let go of the lever the hydraulics bled off and the tractor dropped back to the ground. If I hold the lever, the hydraulics will hold the blade down. Did possibly over-stroking the cylinder blow a seal or even ruin the cylinder? Or could it be something else?