TM 5-4220-226-14&P Table 2-1.  Operator's Preventive Maintenance Checks and Services - CONT Item No Interval Location Item to check service Procedure Not fully mission capable if: 2 Before EXTERIOR Inspect for loose mounting hardware. Bent tube is defective. Side Block Inspect bent tube for dents or other Valve handles are Assembly damage.  Check moving parts such as the difficult to operate. steady flow and emergency air supply valve knobs for smooth and proper operation. 3 Before EXTERIOR Close steady flow valve and open Valve is defective. One Way Valve emergency air supply valve.  Connect Assembly emergency air cylinder whip to emergency air inlet.  Open emergency air cylinder valve and turn in on dial-a-breath knob until it stops freeflow.  Check for leaks at the umbilical connection. 4 Before EXTERIOR Inspect for loose mounting hardware and Dial-a-breath knob and Demand excessive dents or other damage that purge button do not Regulator would interfere with its function.  Check operate smoothly. dial-a-breath knob and purge button for smooth and proper operation. 5 Before INTERIOR Inspect the mask for dirt, cracks, or any Mask is cracked or torn. Oral-Nasal Mask signs of deterioration.  Ensure the mask is properly positioned on the demand regulator mounting nut. 6 Before INTERIOR Inspect for proper operation.  The nose Nose clearing device Nose Clearing clearing device knob should turn smoothly does not operate Device as well as sliding in and out smoothly. smoothly. 7 Before INTERIOR Inspect for dents, cracks, or any sign of Port Retainer damage.  Remove any sand or dirt from the interior of the face port which might cause scratches when anti-fogging solution is applied. 8 Before INTERIOR Inspect for loose mounting hardware. Damage restricts air Muffler Air Train Check for dents, cracks, bends, or any flow. other sign of damage. 9 Before EXTERIOR Inspect for cracks, cuts, tears, or any Damage would interfere Exhaust other sign of damage. with proper operation. Tube/Whisker Exhaust 10 Before EXTERIOR Inspect for dents, cracks, or any other Damage interferes with Exhaust Valve sign of damage.  Remove main exhaust operation. Assembly cover and lubricate valve with silicone lubricant.  Reinstall cover. 2-3