As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER REPLACING WHEEL BRAKE ASSEMBLIES, WENT TO BLEED BRAKE SYSTEM. NO BRAKE RESPONSE ON PILOT'S LEFT BRAKE. TROUBLESHOT TO POWER BRAKE VALVE. FOUND PISTON ROD BROKEN AND LODGED IN OPERATING LINKAGE. THE PILOT HAD NOT REPORTED A PROBLEM WITH THE BRAKE SYSTEM. REPLACED POWER BRAKE VALVE WITH NEW PART, BLED SYSTEM, OPERATIONAL CHECKS GOOD.