What was found
AFTER T/O, NON FLYING PILOT SELECTED FLAPS FROM 5 DEG TO 2 DEG CREW NOTICED AN ILLUMINATED LE FLAPS AMBER LIGHT WITH ASSOCIATED LOSS OF SYS A HYDRAULIC FLUID. SO FLAP CONFIGURATION PANEL INDICATED AN AMBER NR 4 SLAT. CREW FOLLOWED ALL APPLICABLE QRH PROCEDURES THEN RETURNED TO LANDING. DID NOT SHUT OFF SYS A FLUID SWITCHES. VERIFIED NR 4 SLAT ACTUATOR FAILED. REMOVED AND REPLACED NR 4 LEADING EDGE SLAT ACTUATOR OPS AND LEAK CHECK GOOD PER M/M 27-81-032-4. R/I FROM FACT, PREMATURE REMOVED AND REPLACED OFF MFG 2-690029-13,