As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED AFTER LANDING AND DURING TAXI "PILOT SIDE LEFT BRAKE GOES FLAT". MAINTENANCE PERFORMED TROUBLESHOOTING AND FOUND THAT THE PILOTS LEFT PEDAL BRAKE MASTER CYLINDER WAS FULLY COMPRESSING CAUSING PEDAL TO GO ALL THE WAY TO THE FLOOR. PILOTS LEFT PEDAL BRAKE MASTER CYLINDER WAS REMOVED AND REPLACED, OPERATIONAL CHECK SUCCESSFUL.