I have 1850 the hydraulic are ok except after I got done mowing last year, using the single acting cylinder, and the raking with hydraulic powered  rake worked ok with the by-pass open. I closed the by-pass and 3 point lifts ok but there is no power ( with a gage and operation of the right lever moving it forward for operation of double acting cylinder with the disk no power in forward position. 
Since the 3 point and left side hydraulics works ok with a double acting cylinder. Would it make sense that the restrictor valve is out of adjustment on the right is the problem?
I am not going to mess with it until I get done hay but would like to fix it.
Thanks for any insight.
Darryl