What was found
DURING DESCENT NOTICED A SYS HYDRAULIC QUANTITY LEVEL DROPPING. A SYS LOW PRESSURE LIGHT ILLUMINATED. CONFIGURED AC FOR A SYS HYDRAULIC FAILURE CONTINUED FLIGHT WITH B SYS. APPROX 5 MINUTES LATER, LOW PRESSURE WARNING ILLUMINATED ON BOTH B SYS LOW PRESSURE WARNING LIGHTS, FLIGHT CREW OBSERVED A AND B PRESSURE INDICATION DROPPED TO ZERO AT THE SAME TIME, B SYS LOW QUANTITY DID NOT ILLUMINATE. CONFIGURED AC FOR MANUAL REVERSION, DIVERTED, MADE UNEVENTFUL LANDING. B SYS DID NOT LOSE FLUID. REPLACED HYDRAULIC TUBE ASSEMBLY TO 1 ENGINE DRIVEN HYDRAULIC PUMP ALSO CHANGED NR 2 ENGINE DRIVEN HYDRAULIC PUMP AND THE MANIFOLD PRESSURIZATION REGULATOR, NO FURTHER DISCREPANCIES. AC RETURNED TO SERVICE.