Need Help with a GR2120

I bought this GR 2120 diesel new a few years ago. I have used it strictly for snow blowing. The mower deck is for all intents and purposes new (as in it has never cut a blade of grass). The tractor has 149 hours of operating time and has not been a problem (until now) .

I have read the owner's manual on attaching the mower deck and even watched a few videos on the procedure.
I am following the procedure from the manual "step-by-step".
No matter what I've tried the rear-links will not drop down to the lowered position.

I know that the Kubota hydraulic system is pressure up and gravity down.

I assumed that due to not using the mower the rear links were retracted and would extend once the weight of the mower deck was attached that the "Rear Links" would extend when the leaver was actuated to lower the mower deck.

With a lot of effort I got the mower deck hung into position and attached. There is one problem. With the deck in the full-up position I can not get the drive shaft attached to the gear box .

The mower deck will not lower either !
I have a brand new mower neck that is "stuck" in the up position !
Can anyone offer some advice to get this mower deck lowered ?

Thanks
Herm

Update:
I got the mower deck to lower by opening the fitting on the hydraulic lift actuator. This "bleed" let the mower deck drop down (should have thought of this sooner) and I installed the drive shaft.
However I still have no hydraulic power to lift the mower deck. I know the hydraulics are working when I removed the snow blower the pressure worked just fine.

Tomorrow I'll try a bleed of the rear side of the system as that has not been purged / cycled since this machine was purchased . I am hoping that I just have a big fat air pocket in the rear side of the hydraulics .