521/522 DURING DT FOUND AIR LEAK FAIL 1. ~~~~~ 521/522 DURING DT FOUND AIR LEAK FAIL 1.4 BAR/5 MINS.  2522 #2E BCP test point found air leakage. Replaced & security checked - OK. Further checked/found #1521 air leakage from ACU exhaust pipe due to faulty B13 v/v. Replaced & security checked - OK. Performed air leak test & passed = 0.4 bar/5 mins.  Izzul/Tarmidzi/Nelson 44438