As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LT BRAKE PEDAL ON FO'S SIDE SPONGY, SQK 2. REMOVED AND REPLACED CHECK VALVE FOR CABIN PRESSURE TO BRAKE RESERVOIR. REMOVED AND REPLACED PRESSURE RELIEF VALVE FOR BRAKE RESERVOIR. ALL WORK DONE IAW MM 20-10-01 REMOVED AND REPLACED MASTER CYLINDER IN-LINE FILTER REF SB560-32-35 CLEANED ALL FOUR MASTER CYLINDERS AND RAN ALL BRAKE PEDALS. FOUND PILOT IB MASTER CYLINDER LEAKING AT PISTON SEALS REMOVED AND REPLACED PILOT IB MASTER CYLINDER IAW CH 32-42-02 REV. 12 BLEED BRAKES IAW MM 32-42-00 REV 23.