What was found
LOWER FUSELAGE PRESSURIZATION LEAK AT EXTERNAL REPAIR FWD EDGE AT STA 907 AT STRINGER 20L AT LAP SEAM AND BUTT SPLICE DOWN TO STR 25L LAP SEAM. REMOVED FASTENERS IN EXISTING REPAIR AT STR 20L STA 907 - 917. REAMED HOLES TO PROPER SIZE IAW SRM 51-30-05, FIG 3 & 4. NDT INSP WAS PREFORMED ON THE HOLES, NO CRACKS DETECTED IAW NDT MANUAL 51-00-00. INSTALLED FASTENERS WET WITH SEALANT IAW SRM 51-30-2. PRESSURIZATION LEAK WAS DUE TO IMPORPER SEALING WHEN REPAIR WAS INSTALLED ON ACFT AT A PREVIOUS DATE.