As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WITH PARKING BRAKE APPLIED ACC PSI NORMAL, BRAKE TRIPLE INDICATOR READS ZERO. PARKING BRAKE NOT FUNCTIONAL. ACFT ROLLED BACK A FEW FEET BUT WAS SAFELY STOPPED. PERFORMED TEST OF BRAKE SYS IAW AMM 32-24-50-07-10-00-1A. OPS CHECKED AND TESTED GOOD, COULD NOT REPRODUCE. NO FAULTS NOTED AT THIS TIME.