Bobcat 334 Hydraulic swing valve problem

[Gaogle]

I have 3 Bobcat 334 Mini excavators. One of them will only swing one direction. Thinking it was the swing motor, I replaced that. Same problem with the new motor. I was told by the local bobcat dealer that the problem is with the swing valve BUT that Bobcat no longer makes that valve.

I'm shocked - with hundreds of thousands of 334 / 331 machines still in use, it seems ridiculous that there is no valve replacement available.. Any thoughts or ideas?