Direct support and general support maintenance manual including

TM 9-2815-225-34&P 0004 00
DIRECT SUPPORT AND GENERAL SUPPORT
MAINTENANCE MANUAL
INCLUDING REPAIR PARTS AND SPECIAL TOOLS LIST (RPSTL)
FOR
M915, M915A1, M915A4, M916, M920 VEHICLES
NSN 2815-01-082-8125 P/N NTC400-3652-02 CUMMINS NTC-400 BIG CAM I DIESEL ENGINE
W/CONTAINER
NSN 2815-01-142-2745 P/N 11669835 CUMMINS NTC-400 BIG CAM III DIESEL ENGINE
W/CONTAINER
ENGINE TROUBLESHOOTING
SCOPE
This Work Package (WP) contains troubleshooting information to diagnose and correct engine
malfunctions for Big Cam I and Big Cam III engines. Use this information in conjunction with
troubleshooting procedures in TM 9-2320-273-20 and TM 9-2320-273-34 for Big Cam I, and
TM 9-2320-283-20 and TM 9-2320-283-34 for Big Cam III. For further engine troubleshooting
information, refer to the Cummins Troubleshooting and Repair Manual, NT 855 Engines, Bulletin No.
3810298-00.
Troubleshooting procedures are organized by malfunction, followed by a test or inspection to determine
the corrective action required. Each step has a corrective action, along with appropriate WP references.
Steps listed under each malfunction are in the order in which the causes are most likely to occur.
GUIDELINES
Observe the following guidelines when performing troubleshooting procedures.
WARNING
Operating a deadlined vehicle without preliminary inspection
will cause further damage to a malfunctioning component and
possible injury to personnel.
1. Check all tags, service request forms, and vehicle logbooks for repair history. This may provide
information as to the source of the problem.
2. Debrief the operator (if possible) for a general description of the problem, then attempt to verify
the fault.
3. When troubleshooting, always check the easiest and most obvious things first. This simple rule
saves time and trouble. For example, low power complaints are often the result of loose throttle
linkage, dirty fuel, or clogged air filters, and excessive oil consumption is often the result of leaky
gaskets or loose line connections.
4. Double-check before disassembly. The source of many engine problems can be traced to more than
one part in a system. For example, excessive fuel consumption may not be caused by the fuel
pump alone. Instead, the trouble could be a clogged air cleaner or a restricted exhaust passage
causing severe back pressure.
0004 00-1