ARMY TM 9-6115-670-14&P 2-8 Table 2-2.  Operator Preventive Maintenance Checks and Services (PMCS) for Auxiliary Power Unit, 10 kW, 120/240 VAC, 60 Hz – Continued Location Item No. Interval Item to Check/Service Procedure Not Mission Capable If: 5 Before Engine crankcase Check oil level. Replenish oil if needed (para 3.6.). Oil level is below lower notch in dip stick. 6 During Generator Set Check for fluid and exhaust leaks. Exhaust or Level III fluid leak exists (para 2.2.5). 7 During Diesel engine Check for failure of engine to start, sudden stopping, erratic performance, knocking, excessive smoke in exhaust, engine overheating.  Check/ensure fuel shut- off valve is in open position (O). Erratic or Level III fluid leak exists (para 2.2.5). 8 Before (Air Filter) (SICPS, JTACS, and WIN-T). Check air filter for dirt (para 4.45.).  Ensure lid is secured properly. Check filter air flow restriction indicator.  If it indicates restriction (red) or remains red after depressing button on indicator, replace filter. (Fig 2-2) (WIN-T) 9 After Diesel engine Check for excessive fuel usage at vehicle fuel gauge.   Engine should not consume more than 1.31 gallons (4.96 liters) per hour when operating at 3600 rpm and at rated load. Engine uses too much fuel. 10 Before Fuel lines Check for leaks. Any fuel leak exists (Class I, II, or III) (para 2.2.5, 4.7.4). 11 During Fuel shut-off valve Check that it is in an open (O) position. 12 During Control Unit Check for proper readings on AC and DC indicators and frequency meter.  Check that all indicator lamps are out.  Check that hour meter has changed since last operation.  Check WATER gauge for proper water temperature reading. Improper DC inputs, AC out- puts, AC fre- quency indica- tions.  WATER gauge reads high WATER temperature. CAUTION When using an oil of different viscosity from the previous  one,  drain  old  oil.  Never  mix  two different types of oil.