As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SPRINGS PN 69-77855-1 ARE BROKEN IN THE AUXILIARY BRAKE SYSTEM. POSSIBLE CAUSE, IMPROPER HEAT TREATING, AUSTENITE, FATIGUE AND INCREASED SPRING COIL STRESSES. SPRINGS PN 69-77855-1 ARE TO BE REPLACED WITH PN 69-77855-2 SPRINGS ON ACTUATOR ASSYS MANUFACTURED PRIOR TO S/N KE01730 PER BOEING SL 737-SL-27-090-B.