What was found
AT SEATTLE, GATE RETURN, FLAPS DROPPED TO ABOUT 20 DEGREES WHILE AT GATES, AFTER ENGINE START WITH HYD AUS AND TRANS FOR PUMP ON AND ENGINE PUMPS BOTH ON HIGH, FLAPS WOULD NOT MOVE (STILL 20-25 DEGREES) WITH FLAP HANDLE UP/RET. AFTER SEVERAL ATTEMPTS (10 TO 20 CYCLES) FLAPS FINALLY RETRACTED TO UP/RET. REMOVED AND REPLACED BOTH FLAP 2-SPEED CONTROL VALVES AND RT NR 3 FLAP ACTUATOR PER MM. LEAK AND OPS CHECK GOOD. PERFORMED FLAP OPS CHECK PER 27-52-03. FLAPS OPERATE WITHIN LIMITS. OK FOR CONTINUED SERVICE. (M)