Does anyone have any experience with Mighty Viper 5 axis Mills?

I know there are several people on this forum like myself who have to wear multiple hats, so I am tapping this resource as another option for what I am dealing with. If anyone has experience with a Mighty Viper 5 axis mill primarily the 10 ton right angle head part I would love to pick someones brain about it. We are having an issue with the "C" axis not returning home, it stops in absolute @ 0.0 degrees but in machine and relative reads .248 degrees out of center. I however do not think this is our issue, I think when the M code for un-clamp is sent that the unit is not fully un-clamped. Checking the switches I/O it calls as the switch is being made in both directions both clamp and un-clamp, but I daresay I don't trust that as I do not know if it is an actual mechanical switch or a hydrtaulic switch. If we shut the machine down for 4 hours or so we are able to restart it and remove the right angle head then reattach it and it works again for several hours before this situation happens again.

This leads me to believe it is a hydraulic flow issue. So if anyone has any experience with these units and on the off chance has seen this before, please let me know, I am banging my head on this one.

SolidworksGeneral