As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
A SPACER (PN: 5012404-1) WAS INSTALLED NEW FROM STOCK INTO A BRAKE ASSY (PN: 5006749-5R). DURING THE TESTING PROCESS, THE MECHANIC WAS UNABLE TO ACHIEVE THE DESIRABLE SPACING BETWEEN BRAKE PARTS. THE SPACER (PN 5012404-1) WAS REMOVED AND INSPECTED IN REFERENCE TO COMPONENT MM(CMM). THE SPACER WAS FOUND TO BE UNSERVICEABLE IAW CMM. ALL SPACERS IN STOCK HAVE BEEN REMOVED FROM SERVICE AND QUARANTINED.