What was found
DURING CRUISE AT FL200, HYDRAULIC RESERVOIR LOW LEVEL LIGHT ILLUMINATED FOLLOWED BY RESERVOIR LOW PRESS, MAIN PUMP LOW PRESS, AND ELECTRIC PUMP LIGHTS. DIVERTED TO SFO. SWAGGED NR 6 HYDRAULIC RETURN LINE AT RIGHT ENGINE NACELLE. REPLACED RIGHT ENGINE DRIVEN HYDRUALIC PUMP AND SYSTEM RETURN FILTERS. OPERATIONAL CHECK GOOD.