As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CAPTAINS LEFT BRAKE PEDAL GOES TO FLOOR WITHOUT STOPPING AIRCRAFT. WHEN I TAKE FOOT OFF PEDAL & REAPPLY LEFT BRAKE IT WORKS FOR A MOMENT, THEN PEDAL WORKS ITS WAY BACK TO FLOOR AND LOSES BRAKING ABILITY. THIS OCCURS ON LANDING AND TAXI. PERFORMED LOW PRESSURE LINE BLEEDING OF CAPTAINS LEFT BRAKE PEDAL IAW ATR42 JIC 32-42-00 BLD 10000. CHECKED GOOD IAW ATR42 JIC 32-42-00 OPT 10000.