John deere 27d thumb install

[Jberry609]

Hello everyone. I recently purchased a 2014 john deere 27d mini excavator. I decided to add a hydraulic thumb on the machine. There was already lines with quick connects on the machine. I installed the thumb and lines. When I use the thumb it opens good and fast. When I close the thumb it is slow and doesn't hold pressure enough to grab anything. My question is there a way to up the pressure. Or is there a bad valve maybe. Looking for suggestions. I switched the lines and it clamps but won't open.

 

[Diesel Dave]

Welcome to HEF JBerry .
Verify that the auxiliary lines selector valve is in the 2 way flow position.
See info from Operators manual below.
https://techinfo-omview.apps-prod-v...recloud.com/omview/omt223334/09001faa802a9b9f .

 

[92U 3406]

If its in 2 way flow, probably just need to turn up the aux circuit relief for that direction. Definitely recommend using a gauge to dial in the pressure setting. Don't want it too high, the buck curl force can bend thumb cylinders if it can't overpower the thumb circuit.

 

[Jberry609]

Welcome to HEF JBerry .
Verify that the auxiliary lines selector valve is in the 2 way flow position.
See info from Operators manual below.
https://techinfo-omview.apps-prod-v...recloud.com/omview/omt223334/09001faa802a9b9f .

Welcome to HEF JBerry .
Verify that the auxiliary lines selector valve is in the 2 way flow position.
See info from Operators manual below.
https://techinfo-omview.apps-prod-v...recloud.com/omview/omt223334/09001faa802a9b9f .

Thanks diesel Dave. That's exactly what it was ‍♂️