Hello, I a having an issue with a Toyota 8FDU25 and its steering. When it was first reported, the steering was completely locked. I had to tow into shop as it could not steer. I have since replaced the orbital valve (hydrostatic steering valve) as well as the oil/hydraulic oil pump. I have removed the top bolt and spring from the flow divider and inspected the spring for any loss in retention - no loss.

I checked the steer axle cylinder - by disconnecting the hydraulic oil lines (L & R) from the cylinder. I tried steering to see if fluid was come out of one line and not another, which the steering was still very rough. I am out of ideas, would it be the oil control unit? Or could it steel be the hydrostatic?

Thanks I advance.