What was found
ORD - FLT 1556 - EN ROUTE LAS-ORD, AFTER BRINGING HYDRAULIC PUMPS TO OFF AND LOW, THE LEFT GEAR INDICATION RED LIGHT ILLUMINATED. LIGHT WENT OUT AND STAYED OUT AFTER RECYCLING HYDRAULIC PUMPS TO HIGH AND THEN TO LOW. LIGHT STAYED OUT FOR REMAINDER OF FLIGHT. LANDED ORD WITHOUT INCIDENT. REPLACED LEFT GEAR DOOR ACTUATOR. ACCOMPLISHED LEAK CHECKS AND CHECKED AND ADJUSTED LEFT MAIN GEAR UP AND LATCHED PROXIMITY SENSOR. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)