A while ago I posted that my rockshaft arms had lowered themselves and would not raise up. I rebuilt the Rockshaft control valve assembly...everything worked for about 4-5 months until I ran the log splitter off the rear hydraulics again...it worked briefly right after I disconnected the splitter, then shortly after would not after I moved a trailer with the rear hitch on the draw bar. I have been real busy with work so I ignored the tractor other than running it occasionally to turn/clean up the compost pile. After about 2-3 weeks of this today the rockshaft is working again(I literally had brought it into the barn for disassembly). I can only assume that there is a sticky valve (unloading, flow or lower control valve) in the system and that there must be some debris circulating. Would this assessment be correct? So I now am wondering what the next logical step should be. I think I should drain and clean the screens, replace the filter, etc before rebuilding the rockshaft or control valve assemblies?