TM 9-2320-302-10 0012 00-7 Table 1. Preventive Maintenance Checks and Services (PMCS) for M915A3 - Continued. Item No. Interval Location Procedure Not Fully Mission Capable If: Item To Check/ Service 12 Before Instru- ment Panel Gages and Indicator and Warn- ing Lights CAUTION At  1700-2100  rpm,  minimum  engine  oil  pressure for safe operation is 15 psi (103 kPa). If gage does not  show  at  least  15  psi  (103  kPa),  shut  down engine  and  notify  supervisor.   All  warning  lights should go out in approximately 7 seconds.  Failure to follow this caution will damage engine. a. Check oil pressure gage. Read- ing  should  be  15-50  psi  (103- 344 kPa) at idle. a.  Gage  reading  is  not within limits. b. Check  primary  and  secondary air   pressure   gages   for   90-120 psi (621-827 kPa) (green band). b.  Gage reads less than 65    psi    (448    kPa) (yellow band), warning buzzer stays  on,  or  gage  is not operating. c. Check  that  voltmeter  registers within green band. c.  Needle  is  in  yellow or red band. d. Check   that   fuel   supply   gage registers and indicates adequate fuel for mission. e. Check    air    cleaner    restriction indicator. e.  Indicator window shows    20    in.    (51 cm) or more of water vacuum. 13 Before Parking Brake With service brake pedal depressed,     transmission     in D (Drive),  and  engine  at  idle,  pull parking     brake     valve     out     and release service brake pedal. Vehi- cle should not move. Vehicle moves with parking brake applied.