An agricultural harvester comprising a header, a feeder assembly for attaching the header, the harvester further comprising a header lift assembly the header lift assembly comprising: a lift cylinder comprising a sleeve and a piston, wherein the piston is configured to move in an axial direction relative to the sleeve to adjust the height of a header; and a lock assembly coupled to the lift cylinder, whereby: the lock assembly is configured to automatically transition to a first locking position upon extension of the piston in the axial direction to a locking distance from the sleeve; in the first locking position the lock assembly is configured to block retraction of the piston in the axial direction beyond a first distance from the sleeve; the lock assembly is configured to automatically transition from the first locking position to an unlocked position that facilitates retraction of the piston beyond the first distance upon extension of the piston to an unlocking distance; and the lock assembly further comprises a pin and a pathway, the pathway is configured to accommodate the pin, and one of the pin and the pathway is coupled to the sleeve, and the other of the pin and the pathway is coupled to the piston; and characterized in that the pathway comprises a locking pathway and an operating pathway, engagement of the pin within the locking pathway corresponds to the first locking position, and engagement of the pin within the operating pathway corresponds to the unlocked position. a lift cylinder comprising a sleeve and a piston, wherein the piston is configured to move in an axial direction relative to the sleeve to adjust the height of a header; and a lock assembly coupled to the lift cylinder, whereby: the lock assembly is configured to automatically transition to a first locking position upon extension of the piston in the axial direction to a locking distance from the sleeve; in the first locking position the lock assembly is configured to block retraction of the piston in the axial direction beyond a first distance from the sleeve; the lock assembly is configured to automatically transition from the first locking position to an unlocked position that facilitates retraction of the piston beyond the first distance upon extension of the piston to an unlocking distance; and the lock assembly further comprises a pin and a pathway, the pathway is configured to accommodate the pin, and one of the pin and the pathway is coupled to the sleeve, and the other of the pin and the pathway is coupled to the piston; and characterized in that the pathway comprises a locking pathway and an operating pathway, engagement of the pin within the locking pathway corresponds to the first locking position, and engagement of the pin within the operating pathway corresponds to the unlocked position. the lock assembly is configured to automatically transition to a first locking position upon extension of the piston in the axial direction to a locking distance from the sleeve; in the first locking position the lock assembly is configured to block retraction of the piston in the axial direction beyond a first distance from the sleeve; the lock assembly is configured to automatically transition from the first locking position to an unlocked position that facilitates retraction of the piston beyond the first distance upon extension of the piston to an unlocking distance; and the lock assembly further comprises a pin and a pathway, the pathway is configured to accommodate the pin, and one of the pin and the pathway is coupled to the sleeve, and the other of the pin and the pathway is coupled to the piston; and characterized in that the pathway comprises a locking pathway and an operating pathway, engagement of the pin within the locking pathway corresponds to the first locking position, and engagement of the pin within the operating pathway corresponds to the unlocked position.