Backhoe Mechanical or Hydraulic thumb?

[graydog]

It worked. Went to the local industrial supply to get the fittings to match, and connected return to other port.

It picked up a couple hundred pound rock. I gingerly pushed the thumb with the bucket curl, and that worked too. That's less than a full test, but confirms the principle.

Now I'll go back and get a relief line tapped into the supply, with overflow to the return.

 

[graydog]

The relief valve went in with not much fuss, a couple hundred bucks all told, and the thumb is in unrestricted use. Someday I'll use one on another tractor to see if mine is different.

The relief valve comes set to 2500#, less than the bucket curl supposedly. In practice, I set either the bucket or the thumb, squeeze with the other, and off we go. Articulation with a load requires moving (operating) both at once, which I'll get better at.

Thanks again to all who coached me on this -- a good experience and a happy outcome.