As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SPRINGS P/N 69-77855-1 ARE BROKEN IN THE AUXILIARY BRAKE SYSTEM. IMPROPER HEAT-TREATING, AUSTENTITE, FATIGUE AND INCREASED SPRING COIL STRESSES. SPRINGS P/N 69-77855-1 ARE TO BE REPLACED WITH P/N 69-77855-2 SPRINGS ON ACTUATOR ASSEMBLIES MANUFACTURED PRIOR TO S/N KEO1730 PER BOEING SL 737-SL-27-090-B.