An assembly tool for terminating an optical fiber with an optical fiber connector comprises a base having a connector cradle to hold said connector, a buffer clamp activation shuttle slideably disposed on the base to push a sleeve over a buffer clamp of the connector, and an activation mechanism pivotally mounted to the base. The activation mechanism includes an actuation lever to press a securing cap over a mechanical element in the connector, and a drive shaft coupled to the actuation lever. Moving the actuation lever from a first position to a second position activates the buffer clamp activation shuttle and presses the securing cap over the mechanical element.