As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MEX - FLT 1528 - AFTER GATE DEPARTURE DURING TAXI OUT, DIMINISHED BRAKING ACTION NOTED. AIRCRAFT RETURNED TO GATE. REPLACED LEFT MAIN LANDING GEAR BRAKE METERING VALVE. ALSO, REPLACED ANTI-SKID CONTROL BOX. SYSTEM LEAK AND GROUND CHECKED NORMAL OPERATION. (M)