Ctl 70/mtl 20 hydraulic issue

[Rio_Grande]

I have a CTL 70 same as an mtl 20. I have been having trouble with the aux hydro function. Sometimes it acts as if it is in detent mode and the grapple closes all the way or opens all the way. If I mess with the switch I can get it to a neutral position. When I clamp down on something it won't continue to hold pressure unless I hold the button. Any advice would be appriciated.