TM   10-3930-643-20 PRELIMINARY   PROCEDURES.   (cont) 3-5. Organizational  Preventive  Maintenance  Checks  and  Services  (PMCS).    (cont) Organizational   Preventive   Maintenance   Checks   and   Services ITEM TO BE INSPECTED PROCEDURE: CHECK  FOR  AND  HAVE  REPAIRED,  FILLED,  OR  ADJUSTED  AS  NEEDED PERFORM ALL OPERATOR PMCS FIRST Q-Quarterly A-Annually H-Hours I t e m    I n t e r v al No. Q A H Equipment Procedure 9 l SERVICE  BRAKE  ASSEMBLY Check   brake   pads   for   wear. Pads should   not   be   allowed   to   wear below   1/8   in.   thick. Notify Direct   Support   if   replacement is   necessary. ALTERNATOR WARNING COMPRESSED  AIR  HAZARD 10 l Compressed   air   used   for   cleaning   purposes   will   not   exceed   30   psi.   Use only   with   effective   chip   guarding   and   personal   protective   equipment ( g o g g l e s / s h i e l d ,     g l o v e s ,     e t c . ). Blow   dust   from   alternator   using compressed   air   only. 3-10