Cat 279D quick coupler

Hey, have recently had a quick coupler installed on my skid steer. The problem is when I uncouple and attachment the ram does not work. It's like it's stuck and won't move to uncouple the attachment. I keep it greased and it seems to work better (grease the fittings once a week). But that seems a bit much. Has anyone had the same problem?? It just seems the motor for the unit is very week especial when it's used to retract the pins.

Cat 279D quick coupler