What was found
FOUND HYDRAULIC FLUID AROUND AFT END OF LT HYDRAULIC RESERVOIR. CLEANED AREA AND FOUND NOTHING. PRESSURIZED THE NR 1 HYDRAULIC SYST AND FOUND NO LEAK. AFTER SEVERAL FLIGHTS, FOUND SIMILAR HYDR FLUID TRACES AROUND HYD RESERVOIR BUT FOUND NO CRACK. CLEANED AREA AND RAN BOTH ENGINES FOR 30 MINUTES BEFORE LEAK APPEARED. COULD NOT SEE A CRACK VISUALLY. REMOVED AND REPLACED LINE. AFTER REMOVING LINE, IT HAD TO BE BENT BACKWARDS BEFORE CRACK WAS VISIBLE. THE ALUMINUM HYDRAULIC LINES IN THE AFT COMPARTMENT ARE ON THE TOP TEN HIT LIST FOR FAILURES. SUGGEST BEING DILIGENT IN LOOKING FOR LEAKS IN THE AFT COMPARTMENT.