As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE CHECKING APU OIL FOR PRE DEPARTURE CHECK FOUND RED OIL FILTER CLOGGING INDICATOR PROTRUDING FROM FILTER BOWL. PERFORMED BITE CHECK OF CDU NO CURRENT FAULTS. REPLACED APU LUBE OIL FILTER. FILTER CHECK GOOD. OIL FILTER INDICATOR CHECK GOOD. MAG DRAIN PLUG CHECK GOOD. OPERATED APU, NO LEAKS NOTED.