2003 genie s40 oscilating axle cylinders will extend but not retract

I need some help on this dearly, happy to be part of the forum. I have an s40 from 2003, serial s4003-7286. I'm having a problem with the oscilating axle cylinders, they will extend but not retract. Manifold pressure is reading 950psi, which is in spec. Everything seems to be there for it to work, it's got me and a couple genie techs stumped. Any suggestions? Thanks again.

2003 genie s40 oscilating axle cylinders will extend but not retract