Sticking or stuck?
If stuck, first I'd see if both are stuck or just one. That will give you a clue whether is it something common to both (like that hose) or specific to one (like a cylinder).
I have had a cylinder stick during a long sit -- cracked open the bleed screw to free it (which you have to do to remove the drum) then a simple rebuild.
If, on the other hand, you mean they are sort of sticking or grabbing -- then I would remove the drum and look for contamination.