I have a thumb on a case excavator that operates intermittently. Sometimes it works and sometimes it doesn’t, remaining in the open position. An electronic issue with the thumb toggle switch. Or is it a cylinder or hydraulic pump issue?
my vote would be an electronic issue with the switch. take the switch apart and clean it and make sure everything is connected tight.
That was my first thought. There are no obvious signs of cylinder leaking. Thanks!
I had that same issue on a CASE CX160. The thumb had its own control handle and the issue was a wiring issue in that handle.
Good day I suggest the most reliable way to diagnose the issue is to get both hydraulic and electric schematics, in that way you can easily trouble shoot the system. Knowing which Case and if the thumb is a factory fit will also help. Kind regards Uffex.