TM 552210-223-12 TO 45A2-2-14-41 Table 4-1.  Unit Preventive Maintenance Checks and Service(Continued) W - Weekly M - Monthly Q -  Quarterly INTERVAL ITEM ITEM TO BE NO.  W M Q INSPECTED PROCEDURES 21 Safety Warning Remove clapper (para 4-19) and lubricate in Bell Assembly accordance with LO 55-2210-223-12.  Inspect for wear.  Install clapper. 22 Main Generator a. Remove brush covers and inspect interior for grit, dust, and dirt. WARNING Compressed air used for cleaning purposes will not exceed 30 psi (207 kPa).  Do not direct com- pressed air against skin.  Use goggles or full face shield. b. Service main generator by blowing out with dry compressed air. c. Inspect brush holders and brushes for grit and dirt.  Check that brushes do not stick in holders.  Check for proper spring pressure (para 4-38).  Check for minimum brush length of 1-1/4 inches (31.75 mm). d. Check to ensure that the brush pressure springs will not come to within 1/8 inch (3.2 mm) of frame before next inspection. 23 Exciter- a. Remove brush covers and inspect interior Auxiliary for grit, dust, and dirt. Generator WARNING Compressed air used for cleaning purposes will not exceed 30 psi (207 kPa).  Do not direct compres- sed air against skin.  Use goggles or full face shield. b. Service exciter-auxiliary generator by blowing out with dry compressed air. 4-6 TM 552210-223-12 TO 45A2-2-14-41