What was found
APPROX 25 MIN INTO FLIGHT AT ALT 29000 THE GREEN SYSTEM HIGH TEMP CAUTION LIGHT ILLUMINATED. COMPLETED QRH AND SHUT GREEN SYSTEM OFF. HIGH TEMP LIGHT WENT OFF ABOUT A MINUTE LATER. MAINTENANCE INSPECTED HYD SYSTEM, NO LEAKS NOTED. PERFORMED DECAY TEST, OK. NOTED PTU OVERTEMPING PRESSURE CYCLING ERRATICLY. REPLACED PTU IAW 29-20-17, FAULT ISOLATION 29-30-00 FIGURE 111. TEST FLIGHT SATISFACTORY. COMPLETED POST FLIGHT WALKAROUND, NO DISC NOTED AT THIS TIME.