What was found
ACFT RETURNED, DURING CLIMB AT 14,000 FEET, THE FLOW LIGHT TURNED ON AND MESSAGE CABIN ALT WAS SHOWN. MX PERFORMED BOTH A/C PACKS AND PRESSURIZATION VALVES CHECKS IAW MM 21-30-00, NO LEAKS WERE FOUND, RETURN TO SERVICE. THE OVERWEIGHT INSP WAS NOT NECESSARY, ACFT LANDED WITH 135,000 POUNDS AND THE MAXIMUM ALLOWABLE LANDING WEIGHT IS 139, 500 POUNDS.