As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU EXHAUST DUCT OUTER SHROUD WAS FOUND TO BE DETERIORATED DUE TO HYD FLUID LEAKING ON IT. POWER TRANSFER UNIT FILTER ASSY IS LOCATED DIRECTLY ABOVE THE APU EXHAUST DUCT. LEAKS FROM THIS FILTER ASSY WILL CAUSE HYD FLUID TO COME IN CONTACT WITH THE HOT EXHAUST DUCT AND CAUSE COKING AND DETERIORATION TO DUCT.