What was found
PILOT REPORTED: "RIGHT BLEED TRIP OFF LIGHT ILLUMINATED IN FL 390. PERFORMED THE QRH AND THE LIGHT CAME BACK ON". THE PILOT ELECTED TO DO AN AIR TURN BACK AND LAND AT STA: KMIA. AIRCRAFT LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE PERFORMED ENGINE AIR SYSTEM HEALTH CHECK IAW AMM 36-11-00-700-801 UP TO STEP I NUMBER 5, FOUND HIGH STAGE VALVE IN FAULT WITH A LEAK. REMOVED AND REPLACED HIGH STAGE REGULATOR IAW B737 AMM 36-11-07. PENDING LEAK TEST. B. AMBROISE 4784457 ACCOMPLISHED LEAK TEST IAW AMM 36-11-07 NO LEAK NOTED ACTION IAW FIM 36-10 TASK 08-809. ACCOMPLISHED POWER RUN FOR LEFT AND RIGHT ENGINES IAW AMM 71-00-00 AND AMM 36-11-07 OP'S CHECK ON. NO DISCREPANCIES NOTED. AIRCRAFT RETURNED BACK TO SERVICE.