What was found
DURING LANDING, PILOT REPORTED L/R THRUST REVERSER ACCUMULATOR "LOW" LIGHT CAME ON, THRUST REVERSER DEPLOYMENT, AND BOTH HYD PRESS INDICATED "0", WHILE HYD QTY WAS NORMAL AT L 15 AND R 17. PILOT PROCEEDED TO ACCOMP QRH HYD PRESS LOW PROCEDURE BY TURNING TRANSFER PUMP SWITCH "OFF", AND HYD SYS PRESS`S RETURNED TO NORMAL. A/C THEN PROCEEDED TO TAXI TO GATE. INSPECTION BY MX REVEALED PTU, P/N 4100310-6, S/N 1372 WAS LEAKING SO IT WAS REPLACED. AFTER REMOVAL, MX PERSONNEL FOUND DRAIN PORT HOUSING, P/N 4102202-1, INSTALLED ON SUBJECT PTU, HAD CRACKED COMPLETELY AROUND CIRCUMFERENCE. PTU WAS REPORTED TO HAVE 7,330 TSN AND 10,082 CSN, AND IT WAS RETURNED REPAIR STATION FOR INVESTIGATION.