What was found
DESCENDING FROM FL450 TO FL350, THROUGH 38000 FT, DOOR SEAL INDICATION FOLLOWED BY A LOUD NOISE AND CAB ALT WARNING IN SECONDS LATER. VISUALLY INSPECTED MAIN DOOR SEAL. NO DEFECTS OR OTHER DAMAGE WAS NOTED. INSPECTED SECONDARY SEAL. NO DAMAMGE NOTED. NOTED THE GROMMET SEAL BETWEEN THE DOOR AND THE FUSELAGE WAS NOT FULLY INSTALLED IN HINGE. REINSTALLED GROMMET CORRECTLY IAW CE525B M/M CH. 52-10-00. FLUSHED OUT MAIN DOOR SEAL WITH NITROGEN. SUPPLIED VACUUM TO REMOVE ANY MOISTURE. BLEW NITROGEN THROUGH THE MANIFOLD THAT SUPPLIES PRESSURE TO THE DOOR SEAL, NOTED A LITTLE BIT OF VAPOR CAME OUT. REMOVED AFT BAGGAGE TO GAINED ACCESS TO WATER TRAP FOR SUPPLY. CHECKED THAT LINES HAD NO BLOCKAGE AND WERE CLEAR. CLEANED OUT TRAP AND REINSTALLED IAW CE525B AMM 36-10-00. CLOSED UP AFT BAGGAGE. CABIN DOOR SEAL OPS CHECK GOOD