Lost one side of thumb hydraulics

I have a 2006 Doosan Daewoo solar75v excavator that I am converting my manual thumb to a hydraulic thumb. I am using the hammer hydraulics with the foot pedal for control. It has the to way valve on it. I hooked up a test guage to see what pressure I am getting which is 4000 psi. I tested it three times. Each time the pump dead headed when I tested it. I shut it down and removed one of the pilot lines on the control block looking for a pressure adjustment which there is none. Restarted and...

Lost one side of thumb hydraulics

Lost one side of thumb hydraulics