TM 10-6640-238-13 4-7 Table 4-1.  Unit Preventive Maintenance Checks and Services (PMCS) - CONT Q - Quarterly     S - Semi-Annually     A – Annually     B-Bi-Annually Item No. Interval Item to Inspect Procedures Not Fully Mission Capable If: Q S A B 8 Purge System a.    Check purge intake and exhaust doors for good condition. Purge intake and exhaust doors have damage to gaskets, or latches, clogged/damaged screen or filter, or missing or loose fasteners. b.   Check purge intake and exhaust door dampers and motors for good condition. Purge intake and exhaust door dampers and motors have missing or loose fasteners, or loose or broken motor electrical connections. c.    Check ECU intake ducts located in the machinery room for good condition.. ECU intake ducts have missing or loose fasteners, damage to screens, gaskets, or filters. Dampers have loose or broken electrical connections to motors. d.   Check purge door limit switches for proper operation. Purge door limit switches do not operate properly.  Purge door limit switches have missing hardware or loose electrical connections. 9 Air System a.    Check the compressor for good condition and proper operation. Refer to TM 10-4310-392- 13&P for further PMCS instructions. Compressor inoperative. Compressor has missing or loose mounting hardware, or loose or broken electrical connections. b.   Check air tank for good condition. Air leaks from tank or fittings, or has missing or loose tank mounting hardware. c.    Check pressure switch and gauge for good condition and proper operation. Pressure switch and gauge inoperative, or has broken or loose electrical connections. d.   Check system tubing and piping for good condition. System tubing or piping has leaks. e.    Check system valves for good condition. System valves have leaks.