Mission Predive Setup Procedure (Cont)

TM 5-4220-225-14 Table 2-2. Mission Predive Setup Procedure (Cont). Step Procedure NOTE If handle is loose, tighten the friction drag screws until the desired action is achieved. (12) Rotate valve handle.Motion should be firm and have some resistance but operate smoothly through full range, approximately three turns. (13) Depress the chin button with finger pressure. Motion should be smooth with spring pressure increasing steadily. Upon releasing finger pressure, the valve should shut with spring tension. d. Ambient Exhaust Valve Check. (1) Remove the adjustable exhaust valve cover and inspect the valve body for dirt, corrosion, and damage. Inspect the diffuser for dirt or damage.Replace or clean parts as necessary (2) Remove the diaphragm retainer and inspect the diaphragm for damage and deterioration. (3) Apply a light film of lubricant to the bead of the diaphragm and install the diaphragm and ambient diaphragm retainer. Ensure the diaphragm seats properly. (4) Install the ambient exhaust valve cover. e. Air Adapter Assembly Check. (1) Remove the air adapter cap and filter screen. Inspect the adapter, screen, and cap for dirt, corrosion, and damage. Ensure the nonreturn valve is properly installed. (Do not remove the valve unless it is suspect.) Reinstall screen. (2) Visually inspect for loose or missing screws. Tighten or replace as required. f. Air Supply Whip. (1) Remove the protective caps from the air supply whip and inspect the air supply whip fittings for corrosion and damage. Inspect the gasket for wear or deterioration and lubricate lightly with an approved lubricant. Replace the gasket if required. (2) Install the whip to the helmet air adapter. Ensure it is right. 2-29