What was found
RUNNING A DUCT PRESSURE SPLIT DURING CLIMB AND CRUISE. DURING CLIMB, DUCT SPLIT 25PSI LEFT, DUCT LOW 21PSI. DURING CRUISE AT FL 360, RIGHT DUCT 44PSI, LEFT DUCT 21PSI. ACFT GROUNDED. COMPLETED T/C NG 36WC-0001 FOR ENGINE BLEED AIR HEALTH SYS CHECK. FOUND PCV STICKING, HSV STICKING AND PRSOV LEAKING. REPLACED PCV REF AMM 36-12-02. CHECKED GOOD. REPLACED HSV NR 1 REF AMM 36-11-06. CHECKED GOOD. REPLACED PRSOV REF AMM 36-11-04, CHECKED GOOD. BLEED AIR SYS HEALTH CHECKED GOOD.