Parts came and I'm back at it! I pulled the lift arm cylinder assembly and rebuilt everything. All new o rings and ring backers. Cleaned everything , blew everything all out, honed the cylinder and we have a functioning rear hydraulic system! Everything does what it is suppose to. Only one thing. As the arms are rising I have a screeching noise. I've adjusted the control valve numerous times thinking that the valve is not quite open far enough or a little too far and I hearing the oil shredding. The noise starts when I move the lift leaver and ends when the arms arrive at the end point I select. All the way or partially, it doesn't matter. When the arms reach their destination the hydraulic load comes off and engine rpm are relieved and the noise stops. Any thoughts?