TM 10-3930-659-20 Table 3-1.  Preventive Maintenance Checks and Services (PMCS) (Con't). Not Fully Item Item to Mission No. Interval Check/ Service Procedure Capable If: 15 Annually Air Cleaner WARNING If  NBC  exposure  Is  suspected,  all engine  air  cleaner  air  filter  media should   be   handled   by   personnel wearing protective equipment. Consult  your  NBC  Officer  or  NBC NCO   for   appropriate   handling   or disposal procedures. Change both primary and secondary air filters (see paragraph 5-9). 16 Annually Low and Check and adjust low and high en- High gine idle speeds as required (see Engine Idle paragraph 5-25). Speeds 17 Annually Engine Radiator WARNING DO   NOT   remove   radiator   fill   cap unless  engine  Is  cold.    This  Is  a pressurized    cooling    system    and escaping     steam,     hot     water,     or coolant will cause serious burns. Drain and flush engine radiator (see paragraph 5-38) and overflow tank (see TM 750-254).  Fill engine radia- tor with antifreeze (see para- graph 5-38). 18 Annually Brake a.  Check brake linings for wear (see Linings paragraph 10-7). b.  Inspect brake linings on each b.  One or more linings are worn to pressure plate and on each brake bottom of oil grooves. backing plate for excessive wear (see paragraph 10-7). 3-9