In St. Louis, we have a nearby Precision Rebuilders, which rebuilds components of medium and heavy- duty trucks, such as air compressors, air cylinders, and yes, hydrovacs. They supply most of the local truck shops with remanufactured parts, but I understand they will work directly with customers as well.
Check out their catalogs online at
http://www.precisionrebuilders.com/ and see if you find your hydrovac unit. If so, you can swap it out wth one slightly less "experienced". ;-)
Good luck, and please post with your results.
-Michael
