What was found
HOLDING SHORT FOR TAKEOFF, AIRCRAFTS PARKING HANDLE RELEASED WITH EMERGENCT PARKBRAKE INDICATOR SHOWING DARK, BUT BRAKES REMAINED SET. RESET PARKING BRAKE HANDLE MULTIPLE TIMES, BRAKES REMAINED SET. REMOVED FROM SERVICE. DEPRESSURIZED HYD PRESSURE SYSTEMS 1 AND 2 I/A/W AMM 29-10-00-860-804-A. EMERGENCY BRAKES RELEASED. REMOVED AND REPLACED EMERGENCY PARK BRAKE VALVE. REMOVED I/A/W AMM TASK 32-44-01-000-801-A. INSTALLED I/A/W TASK 32-44-01-400-801-A. OPS TEST GOOD, NO LEAKS NOTED. RETURNED TO SERVICE.