After reading several post about hydraulics on this site< I started to work on my 8N which has a non working system right now. I removed the dipstick side cover and ran the tried to raise the arms and see what would happen. I did not see any bubbles or fluid being agitated. I could just see the motion of the pump in the oil. I want to build my way up to replacing parts and have read about the relief valve. If the valve was stuck open or closed, would I see anything moving in the fluid? I drained the oil and had a bunch of water come out first. I am hoping I don't have a cracked pump cause of the very cold winter we had. On the relief valve, should it just be able to move freely or should it have a specific amount of spring pressure to be able to work? The linkage was all attached and the appeared to move without any problem. Any advice?