I have a MF 240 diesel with steering problems. It used to be difficult to steer, fluid levels were fine, so there was no steering at all. Engine off or idling, or high RPM, the steering wheel only turns left and right. There is no hub in the front. Is this a steering pump problem or could I have something loose on the end of the steering wheel shaft?
This sounds as if the spool valve is stuck in the open position on the steering control valve, in this position the fluid flows but the steering does not move.
I would order a rebuild kit before disassembling it. Make sure you clean very well, clean brake and compressed air works well. Lubricate all o-rings during assembly.
There may be a problem with the power steering pump.