As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SFO - DURING PUSHBACK FOR TRIP 1684, NUMBER THREE BRAKE ROD DROPPED DOWNWARD. AIRCRAFT OUT OF SERVICE FOR REPAIRS. FOUND BRAKE ROD ATTACH PIN MISSING. REPLACED BRAKE ROD AND ALL ATTACHING PARTS INCLUDING ROD BOLTS, BRAKE LINE, BRAKE ASSEMBLY AND WHEEL/TIRE ASSEMBLY. SYSTEM GROUND CHECKED NORMAL OPERATION.