What was found
WIZ DRAIN AT AFT GALLEY AFT OF DOOR 4L IS NOT CLOSING DURING CABIN PRESSURIZATION (SINK DRAIN IS MAKING VERY LOUD NOISE). REQUEST TOMC TO APPROVE MEL3810AC FOR DEFERRAL. REQUEST TOMC TO APPROVE TO APPLY MEL 3810CQ. TOMC APPROVED DEFERRAL MEL3810CQ. ISOLATED DRAIN AS REQUIRED. NOC DESK: 787 NAME: MM. DATE: 16-AUG-23- TOMC APPROVED MEL 3810CA REJECTING USE MEL CARD 38020 FOR GALLEY DRAINS REPLACED WIZ DRAIN AT AFT GALLEY AFT OF DOOR 4L. REF AMM DMC-B787-A-38-31-21-04A-720A-A. PARTS USED: 78-3810-9-9007,QTY :1 ROTABLE PARTS CHANGE WAS INDICATED - TT # 1665018 SN OFF 2479 VALVE, INTERFAC OFF 78-3810-9-9007 2479 ON 78-3810-9-9007 0243.PRESSURIZED CABIN TO 4.0 AND CHECKED FOR AIR NOISE IN AFT GALLEYDRAIN AND NOISE AT DOOR 4 LEFT AND RIGHT, NO NOISE FOUND. REF AMM 05-51-24-00A-280A.