What was found
DUCT PRESSURE SHOWS 10 PSI ON LT SIDE, RT SIDE READS 42 PSI DURING CLIMB. WHEN CABIN PRESSURE APPROACHES 7.5 PSI THE LT SIDE CLIMBS TO MATCH THE RT SIDE PRESSURE. TASK CARD NG-36WC-00001 INITIATED. ACFT GROUNDED. NR 1 ENGINE, PERFORMED ENGINE BLEED AIR SYSTEM HEALTH CHECK T/C NG-36WC-00001, FOUND HSR REVERSE FLOW DIAPHRAGM RUPTURED, R & R HSR, REF AMM 36-11-07.