What was found
(CAN) BLEED VALVE BUTTERFLY VALVE WAS FOUND TO BE OUT OF RIG POSSIBLY SINCE OVERHAUL. THE RACK AND PINION RIGGING OF THE SECTOR GEAR WAS OUT BY ONE TOOTH RESULTING IN NON-PERPENDICULAR CONDITION TO THE AIR FLOW. INTERNAL COMPONENTS OF THE VALVE VERY DIRTY CONDITION FROM ENGINE BLEED AIR AND FINE METAL DUST FROM INTERNAL SPRING VIBRATION AND CHAFING ON THE VALVE HOUSING. DIRTY CONDITION MAY HAVE CAUSED DELAYED CLOSING UNDER HIGH POWER SETTING.