What was found
WITH CLB PWR SET PACK SPLIT MORE THAN 20 PSI. RT PACK 64 PSI LT PACK 42 PSI. CRZ PWR SET LT PACK 41 PSI RT PACK 47 PSI. 1:30 INTO FLT BOTH PACKS 45PSI. ACFT GROUNDED. ACCOMPLISHED NR 1 ENGINE BLEED AIR SYSTEM HEALTH CHECK IAW AMM 36-11-00-700-801 AND TASK CARD NG-36WC-00001. NO DEFECTS NOTED. ACCOMPLISHED NR 2 ENGINE BLEED AIR SYSTEM HEALTH CHECK IAW AMM 36-11-00-700-801 AND TASK CARD NG-36WC-00001. NO DEFECTS NOTED. WITH APU BLEED AIR ON NOTED THAT THE HOSE 16135-81 WAS LEAKING AND THAT THE PRSOV WAS STUCK IN THE OPEN POSITION. REMOVED AND REPLACED HOSE 16135-81. REMOVED AND REPLACED PRSOV IAW AMM 36-11-04-400-801. OPS AND LEAK CHECK GOOD. GROUND VERIFICATION COMPLETED IAW AMM 36-11-00-710-801.