A mechanic was replacing the hydraulic cylinder on a hauling van outrigger. He lifted the vehicle using a hydraulic floor jack and secured it with two jack stands. Then, he used a hydraulic jack to lift the foot extension of the stabilizer leg and connect the extension to the hydraulic piston with a retention pin. He was holding the retention pin in his left hand and placed his right hand against the stabilizer leg housing to balance himself. The leg extension suddenly moved downward while his right ring finger was in a hole on the leg housing, resulting in an amputation.