I have an older L3600 tractor. This issue has been going on for a while but seems to be getting worse. If I pull the 3 pt lever all the way to lift the box blade the hydraulics will not work. The system is "pressurized". When this happens I cant control the FEL. If I push the 3pt lever down some, the pressure stops and the FEL works. It is like the lever has slipped on its mount. I cant tell how this can be adjusted. If I have the lever about 1/2 way the box blade stays up and the FEL works. Anyone else has this issue or thoughts? Thank you.