I have a New Holland L 555 (serial # 713285, think 1987 model) that has bucket tilt problem, this model only has one cylinder for the bucket. I have pulled control valve and had it checked at hydraulic shop and it checked OK. I put a pressure gauge in the bucket cylinder hose line on each side and I have 3000 psi on both sides of cylinders lines when I move the control pedal in either direction. The spool control valve has a pressure regulator which should limit the pressure to 1850 lbs on the cylinders, as indicated in the service manual. The boom cylinders work fine and the drive works fine. The question I have is can the increased pressure on the bucket cylinder spool valve cause this problem. Thanks in advance if someone has some ideas on this.