Post a pick of the hyd couplers on the machine. If you have 340, you have the ports. Comes on all of them since 2011. If you push up against the coupler you will see that it will push in about an inch or so, that is what depressurizes the line. There is no button you can push on the machine. It is the collapsing of the coupler that depressurizes it. Trust me.