As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PART RECEIVED EPOXY REPAIRS THAT FAILED DURING NORMAL SERVICE. EPOXY WAS USED OVER CRACKS WHICH WORKED THROUGH TO THE SURFACE OF THE HARDENED EPOXY ALLOWING THE OIL COOLER TO LEAK AGAIN. SUBMITTER STATED EPOXY FAILURE IS COMMON IN OIL COOLERS AND RECOMMENDED ELIMINATING EPOXY USE IN OIL COOLERS. REF: P.O.C.S. W/O NR 21054.