It has been a week since I changed the motor oil and filter, drained transmission, removed hydraulic filter and cleaned and replaced it,filled trans with new fluid, changed fuel filter. I asked if there was a way to purge the air from the system and told to move the 3 pt up and down to remove any air in system. I tilled about a1/3 acre with no problem. Yesterday will till a small spot in garden the 3 pt started squealing when beening raised. What could be the cause of this? Speedy2