Hi too all, new member here as of today. I just inherited a 03 MF 231S. I have check the forum for a similar thread but no help. The tractor runs great but not so much for the steering. It has a hydrostatic power steering and lift pump on the right side of engine with a pickup tube running to the transfer case for fluid. I have replaced ALL of the filters and fluid, engine, fuel and hydraulic. My issue is that the steering runs great for about three minutes then stops. I thought that I might be getting air in the system because there are air bubbles after it stops. After about ten minutes I can startup and again have steering for three minutes then stops again. The steering wheel just spins around. There are no fluid leaks visible. I am using Legacy tractor fluid which I obtained from a small business that sells a lot of MF parts. He thought that the AW 46 hydraulic fluid I was using was causing the pump to cavitate and lose pressure. Any thoughts would be appreciated.