As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT HYD QTY DECREASED IN FLT WITH BOTH LEFT ELEC AND ENG PUMPS OFF AND PTU CB. PULLED, LOSS WAS SLOWED CONSIDERABLY. FOUND LEFT ENG PUMP PRESSURE FILTER DIFFERENTIAL BUTTON ASSY LEAKING. REPLACED BUTTON ASSY, LEFT PRESSURE AND CASE DRAIN FILTERS. NO CONTAMINATION FOUND, LEAK CKS OK (P/N 291201356).