What was found
SEA FLIGHT NR 2133 AFTER PUSHBACK WHEN RELEASED EMERGENCY BRAKE NR 1 HYDRAULIC QUANTITY'S PRESSURE DROPPED TO 0. FOLLOWED BY NR 1 ENGINE HYDRAULIC PUMP AND ASSOCIATED CAUTION LIGHT. APPROXIMATELY 2-3 MINUTES NR 1 ENGINE RAN PRIOR TO SHUTDOWN. MAINTENANCE FOUND LEFT HAND NACELLE HYDRAULIC LINE FAILED/CRACKED. REPLACED LINE. SERVICED NR 1 HYDRAULIC SYSTEM, PRESSURIZED SYSTEM, CYCLED ALL COMPONENTS, BLED RESERVOIR OF AIR. SERVICED HYDRAULIC SYSTEM TO FULL. HYDRAULIC LINE LEAK CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.