What was found
WHILE IN CRUISE, FLIGHT CREW RECEIVED AN AMBER "HYD VOLUME LOW A" EICAS MESSAGE ENROUTE TO DESTINATION. HYD INDICATION SHOWED 14 PERCENT AND DECREASING. CREW UTILIZED THE CHECKLIST AND UNLOADED THE A SYS HYD PUMP AND PULLED THE PTU CIRCUIT BREAKER. AN EMERGENCY WAS DECLARED AND EMERGENCY LANDING GEAR EXTENSION SYS WAS USED TO EXTENT THE GEAR ON APPROACH. AN UNEVENTFUL LANDING WAS PERFORMED. TECH WAS DISPATCHED TO INSPECT AND REPAIR THE ACFT. UPON FURTHER INSP, IT WAS DISCOVERED THAT THE AUXILIARY HYD PRESSURE TRANSDUCER WAS LEAKING FROM THE O-RING SEAL. THE O-RING SEAL WAS REPLACED AND THE HYD SYS BLED. OPS CHECKS WERE NORMAL. THE ACFT WAS FERRIED TO MX FACILITY TO SERVICE THE EMERGENCY LANDING GEAR EXTENSION SYS.