Daily Predive Procedures (Cont)

TM 5-4220-225-14 Table 2-3. Daily Predive Procedures (Cont). Step Procedure c. Locking Device Assembly Inspection. NOTE Apply only enough lubricant to coat item concerned without excess. (1) Ensure locking pins are in good condition and operate freely. Check that detent balls operate properly. Apply a light film of lubricant to locking pins. (2) Inspect locking pins for corrosion, bends or cracks. (3) Inspect helmet lugs for corrosion, dents, and loose or damaged mounting screws. d. Exhaust Valve Inspection. (1) Check exhaust valve in accordance with applicable procedure below. (2) Lay helmet assembly on its right side with exhaust valve facing up. e. Adjustable Exhaust Valve Check. NOTE If handle is loose, tighten friction drag screws until desired action is achieved. (1) Rotate valve handle.Motion should be firm and have some resistance but operate smoothly through full range, approxi- mately three turns. (2) Depress the chin button with finger pressure. Motion should be smooth with spring pressure increasing steadily. Upon releasing finger pressure, valve should shut with spring tension. f. Ambient Exhaust Valve Check. (1) Remove exhaust valve cover and inspect valve body for dirt, corrosion, and damage.Inspect diffuser for dirt or damage. Replace or clean parts as necessary. 2-32