A pin lock for a prosthetic device in a vacuum assisted suspension system includes a pin defining a longitudinally elongate bore and at least one passageway extending obliquely relative to the bore and communicating therewith at a proximal end of the pin. The pin lock also includes a locking mechanism having a receiving port arranged to receive the pin and a channel located at a distal end of the receiving port and adapted to communicate with the bore to exhaust air through the pin therefrom.