What was found
ON CLIMB OUT IN TEENS ON ENGINE BLEED SOURCE R PACK HI PRESS CAUTION MESSAGE. RAN QRH, DID NOT RECOVER RIGHT HAND PACK. CONTINUED CLIMB, GOT L PACK HI PRESS CAUTION MESSAGE. RAN QRH. WAS ABLE TO RECOVER LH PACK. RETURNED TO FIELD. (FLIGHT #5593 FILED CLOSED) PER FIM 21-50-00 REMOVED AND REPLACED RIGHT PACK PRESSURE REGULATING SHUT OFF VALVE PER AMM 21-51-43. PERFORMED OPERATIONAL CHECK OF RIGHT PRSOV PER AMM 21-51-43. OPERATIONAL CHECK GOOD. REMOVED AND REPLACED OVER PRESSURE SWITCHES S5HG AND S12HG PER AMM 21-51-22 AND PERFORMED OPERATION CHECK OF PRESSURE SWITCHES. OPERATIONAL CHECK GOOD. PERFORMED OPERATIONAL CHECK OF RIGHT AND LEFT PACKS PER AMM 21-51-00. GOOD FOR CONTINUED SERVICE.