An injection system comprising:a syringe body having a distal portion and a proximal portion, the syringe body defining a pumping chambera syringe plunger located in the pumping chamber and adapted for reciprocal motion between a position proximate to the proximal portion and the distal portion, the syringe plunger having a first aperture disposed at a proximal portion thereof andan actuating shaft coupled to the plunger and movable through the syringe body to control movement of the plunger, the actuating shaft having a pivot member disposed at a distal portion thereofa release actuator disposed at a proximal portion of the injection systemwherein a distal portion of the pivot member is adapted to project radially inwardly when contacted by a sidewall of the first aperture to form a releasable engagement with the syringe plunger andwherein the distal portion of the pivot member is adapted to project radially inwardly to disengage the syringe plunger from the actuating shaft when a proximal portion of the pivot member slidingly contacts the release actuator and moves radially inwardly.