We recently acquired a used TCM FG25N4 and are having some issues with the steering. If you're moving at all the steering is fine, but if you stop you can only turn the wheels a couple of degrees in either direction before the steering becomes very difficult.

This model has a valve mounted onto the end of the steering cylinder that controls the assist. I can barely turn the wheel enough to shift this valve and the engine rpm drops slightly and I can hear the hydraulic pump taking up a load.

I suspect the cylinder is shot and bypassing fluid internally but I've never seen a setup like this one before and was hoping someone here would be more familiar with this valve. Ideally I'd like to put a rebuild kit in it while I've got everything apart but I can't seem to find any info regarding it.

If anyone can point me in the right direction I'd appreciate it.