As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE STOPPED ON THE TAXI WAY DURING TAXI OUT WITH BRAKES SET. A/C STARTED TO ROLL. S/O NOTED 'B' SYSTEM PRESSURE DROPPING TO ZERO WITH BOTH HYD B LIGHTS ON. FOUND RT ANTI-SKID MODULE CASE BROKEN IN TWO AT FILTER CASE. REPLACED MODULE.