What was found
AIRCRAFT 384, ATB, RETURNED TO LAX DUE TO A PRESSURIZATION LEAK AT DOOR 4R, UNABLE TO HOLD CABIN PRESSURE. CORRECTIVE ACTION: REMOVED DOOR 4R SCUFF PLATE AND SCRAPPED OFF OLD SEALANT AND CLEANED AREA. INSTALLED NEW SCUFF PLATE AND SEALANT. PRESSURIZED AIRCRAFT, NO LEAKS FOUND.