What was found
DURING CRUISE FLIGHT AT FL 360 RECEIVED AN EICAS " LT HYD QTY " MESSAGE, LT SYS QUANTITY READ .48, AND "RSVR" LIGHT ILLUMINATED ON HYD OVERHEAD PANEL. LT SYS QUANTITY WAS DECREASING .01 EVERY FEW SECONDS, LOWERED GEAR WITH QUANTITY READING ABOUT .25. RECEIVED INTERMITTENT "LT HYD ENG PUMP" MESSAGE. BROUGHT FLAPS TO 20 AND LT QUANTITY DECREASED TO AROUND .22 AND HELD STEADY. "LT HYD ENG PUMP" THEN ILLUMINATED STEADY, TURNED OFF THE LT ENGINE HYD PUMP. SPOILERS, REVERSERS, BRAKES AND NOSE WHEEL STEERING WORKED NORMALLY. INSTALLED LEFT ELEVATOR POWER CONTROL ACTUATOR OPS AND LEAK CHECKED GOOD PER AMM 27-31-05-4.