Spool valve stuck.

[Babongo]

My Bobcat 642 malfunctioned. While operating, the lift arms uncontrollably rose to full extension. The tilt cylinder also extended fully. Both foot controls felt jammed and were unresponsive. At the hydraulic control valve, we noticed that the top spool was protruding more than normal. At the rear, the end cover of this spool had cracked, and one mounting ear was separated from the cover. We disconnected the linkage, and attempted to remove the spool from the rear. It slid about 1 inch, then stopped. It sounded and felt like metal to metal interference. We removed the load check nut, which was intact, and seemed fine. Same result. The spool is stuck. Can anyone offer some insight? Are we missing something, should anything else be removed to release the spool? This is a 3 spool control valve, Bobcat #6586287.

 

[flyerdan]

Somewhere in the manual thread there is a book called Melroe Control Valves. It should cover all of the disassembly and inspection procedures, rebuilding tips, etc.
Always good to have diagrams showing how things go together, and come apart.