What was found
(CAN) AT TOP OF DESCENT, AIRCRAFT BEGAN TO LOSE A-SYSTEM HYDRAULIC FLUID, A-SYSTEM PRESS FLUCTUATING BETWEEN 3,000 AND 2,500 PSI. ACFT STOPPED ON RUNWAY AND T OWED TO RAMP. FOUND HEAVY LEAK AT NR 2 ENG HYDRAULIC PUMP AND NR 1 CASE DRAIN HAD CARBON RUBBER CONTAMINANTS. BOTH PUMPS AND CASE DRAIN FILTER REPLACED. SYSTEM SERVICED AND LEAK CHECK CARRIED OUT, A/C SERVICEABLE.