ITEM INTERVAL ITEM TO BE PROCEDURES CHECK FOR AND HAVE REPAIRED OR ADJUSTED EQUIPMENT IS NOT READY NO. B    D    A D    W   M    Q   S A INSPECTED AS NECESSARY AVAILABLE IF TM 55-1930-209-14&P-7 Table C-1.  Preventive Maintenance Checks and Services for Compressed Air System (Continued) B - Before D - Daily Q - Quarterly D - During W- Weekly S - Semiannually A - After M - Monthly A - Annually m.  Air filter 2 (oil removal filter).  if air station 6 fails air quality check and for semian- nual maintenance services, perform these procedures: 1)   Shut down air compressor system 2)   Redtag power panel 1 circuit breaker 3P5 indicating, “WARNING - DO NOT ACTIVATE.  REPAIRS BEING MADE.” 3)   Without using a wrench, manually unscrew oil removal filter bowl ring nut attaching metal bowl to filter head. Remove bowl ring nut, metal bowl, and bowl O-ring. 4)   Unscrew hex nut and remove rod O- ring gasket, filter element, and gasket O-ring.  Rod/element screw should remain attached to filter head.  If rod/ element screw unscrews from filter head, screw it back into filter head. 5)   Replace filter element (CAGEC 31408, P/N CKF-507).  If gasket O-ring and rod O-ring gasket are worn or dam- aged, replace them. 6)   Place gasket O-ring on top of new filter element and slide element over rod/element screw.  Hold In place by hand and install rod O-ring gasket over rod/element screw.  Screw on hex nut.  Before tightening nut, check that filter element is squarely set against filter head.  Then tighten hex nut hand tight. 7)   Clean metal bowl with warm soapy water, rinse, and dry with lint-free cloth. NOTE Bowl O-ring must be replaced dry, without any silicone lubricant C-19