What was found
CREW REPORTED THE HYDRAULIC FAIL LIGHT ILLUMINATED ON THE CWP. CREW SELECTED TO OVERRIDE AND QUANTITY WENT TO ZERO. EMERGENCY WAS DECLARED AND CREW RETURNED TO BWI. GEAR WAS EXTENDED BY EMERGENCY EXTENSION. MAINTENANCE REPLACED THE NOSE LANDING GEAR MAIN ACTUATOR HYDRAULIC LINE IAW MM. OPERATIONAL CHECK WAS GOOD AND AIRCRAFT WAS RETURNED TO SERVICE. MAIN LANDING GEAR SEPARATION BOLTS WERE ALSO REPLACED IAW SAAB MM. (M)