They are probably siezed from lack of lubrication. That happened a few times with mine. The first time water got inside and created hydrauilic lock. My Lbs removed the screws and forced penetrating oil inside, and eventually got them apart. A good cleaning and relube and they were better than new. When they got sticky again, I cleaned and regreased myself.
If the elastomers are still good, relube them with synthetic grease, not petrroleum based. The petroleum based greases deteriorate the urethane.