This question requires an explanation on the physics around a hydraulic lock or hydraulic bind not caused by mechanical damage to the piston chamber. Further illustration is given by the following scenerio: What are the possible reasons for a hydraulic bind occuring in the lock chamber of an hydraulically actuated piston designed to stroke a mandrel behind locking segments which then expand over a load shoulder to grip a groove profile on a seperately standing hub. This situation is relevant to the functioning of subsea flowline connectors for subsea completions. Sometimes a secondary release mechanism is employed, but what brought this question up is even if you use a secondary release mechanism, how will that overcome the hydraulic bind in the primary piston locking chamber without being able to vent that chamber. If you could vent the chamber that would bleed it off and eliminate the bind... unless my understanding of a bind is inaccurate in which case, I stand to be corrected.