As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE RT ENGINE HYD PRESSURE SWITCH LOCATED IN THE AFT EQUIPMENT BAY FAILED AND LEAKED HYDRAULIC FLUID EXTERNALLY. THIS CAUSED A FAILURE OF THE PRIMARY HYDRAULIC SYSTEM. THE SWITCH IS A KNOWN PROBLEM AND HAS BEEN REPLACED WITH AN IMPROVED STYLE KIT BY SB 1125-29-188. BOTH ENGINE DRIVEN HYDRAULIC PUMPS WERE REPLACED, THE HYDRAULIC SYSTEM WAS FLUSHED AND ALL THE FILTERS WERE REPLACED. INCORPORATION OF SB 1125-29-188 WILL PREVENT RECURENCE.