I think I've bought a later model Takeuchi 290 to replace my older zx75 Ingersoll rand excavator. The 290 has a tag quick coupler which I hate them. I was wondering what hyd. circuit you plumb into to make a hyd. pin grabber work? The 75 has it on the blade control. I'm going to see if they are close enough to swap.
Pin grabbers use bucket curl pressure, by tapping into the circuit feeding the barrel end of the bucket cylinder.