This is slightly off-topic, but I need to fix the power steering on an old JCB backhoe loader, and I thought there might be an expert here who could offer some suggestions. I think the design of this power steering system dates back a long way. The machine has a regular tractor steering box, but in between the steering link and the crank which turns the wheels is a hydraulic ram. One end of the ram is attached to the chassis, the other end to the steering crank (i.e., the crank at the top of the king pin) and the link from the steering box attaches to a large pin on the side of the ram. It appears that when a force is applied to this pin, it operates a pair of spool valves inside the body of the ram. A separate pump operates the steering from the pump which drives the backhoe and loader. I think - but I'm not sure - that the steering pump continuously forces oil through a small orifice and the spool valves simply divert a bit of oil into the ram when the steering wheel is turned. This avoids needing a pressure relief valve I guess. The steering ram/valve unit is marked "Hydrosteer 33/64. Patents Pending. VC140017." The steering doesn't work, but the ram isn't leaking or damaged, and the spool valves seem to move freely enough. I wonder if it is some kind of adjustment problem. I know the chances are slim, but is anyone here familiar with this kind of hydraulic steering and what the common problems are?