I have a 2001 John Deere 120 excavator that I’m adding a thumb to. I have ran hoses from the valve bank up the boom to the cylinder. I have added a 12v solenoid valve and relief valve, teed into pilot line and have ran pilot to the top and bottom of the valve. I have it functioning to a point. If I activate one direction it does not stop when I let off the button. If I hit the other button it either changes direction, or occasionally will stop. Anyone have any idea what I’m missing, or doing wrong?
Welcome to HEF DillyBob ! Please supply a machine serial number. Post up lots of pictures of what you installed.
@DillyBob , Sounds like you have the wrong style/ configuration of pilot solenoid valve. When the closed center pilot solenoid valve is in neutral ,the 2 hoses you installed at the control valve spool caps must be able to drain back to tank. This allows the control valve spool to return back to the centre position.
Sounds like your D03 solenoid valve has a cylinder spool in it; it needs a motor spool