tbran
Guest
test for pressure, you can dead head a pressure guage right into the line you take off the rotary coupling in the main shaft. IF you have no pressure and the valve is fully stroking , the problme is in the valve's relief valve - it can be removed and adjusted or replaced. If you do have pressure 250-300 n's you have a mechanical problem - probably on the input lower shaft. Remove the belt and see if it now closes or you can probably just see the belt getting tighter as you look out the cab window while holding the lever forward.