I have a to30 that when I got the lift arms didn't work. It had been sitting a while and thinking the system may have air in it I started the tractor with pto on and lift control up and applied air. After applying a little air for 20 seconds the lift arms raised. Now the arms raise but they raise all the way up no mater the lift arms control position. And they will not go down with the control lever. The arms will go down if I cut the pto off or I can go behind the tractor ( running with pto on) and push the arms down with the control lever up or down. Any help would be greatly appreciated thank you.