You don't need to disconnect any hoses unless you want to actually see the flow into a bucket.
For ordinary purging of air, just cycle the cyls to full extension and full retract. The air will exit the cyl into the return circuit.
If you have cycle the cyl many times throughout this thread length, there should be no air in the system.
The only thing that I can think of that would stop a cyl from fully extending or fully retracting, is if the return circuit is restricted, meaning there is no place for the fluid to go.
Is the FEL relief going off while extending the curl cyl's, and if so, that means you are working at relief pressure. There is no logical reason for the cyl not to function, unless something downstream is blocking the flow, or a worn spot causing the cyl seals to leak near full retracted position..
Is there a switch or lever you have to move to a certain position, maybe it is half way or something.
If you continue to get air in the cyl, check for a suction leak on the pump.
We haven't seen any pressure readings yet.