As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOUD HISS COMING FROM AFT PART OF F/O SIDE WINDOW. F/O SLIDING WINDOW BULB SEAL LEAKS ACCESSIVELY DURING PRESSURIZATION, BULB SEAL IS DEFORMED ALSO. RPLD F/O SLIDING WINDOW BULB SEAL. PRESSURIZED ACFT TO 4D PSI, STILL HAVE LEAKAGE AT FWD LWR PORTION OF WINDOW (MARKED) BUT NO NOISE NOTED.