It is necessary for you to know how fluid leaks affect the status of your equipment. The following are definitions of the
types/classes of leakage you need to know to be able to determine the status of your equipment. Learn and be familiar with them
and remember--When in doubt, notify your supervisor.
Equipment operation is allowable with minor leakage (Class I or II) with exception of fuel leaks.
Consideration must be given to fluid capacity in item/system being checked/inspected. When in doubt,
notify your supervisor.
When operating with Class I or II leaks, continue to check fluid levels as required in your PMCS. Class
III leaks require corrective action and should be reported to your supervisor.
Leakage definitions for Unit PMCS:
CLASS I--Seepage of fluid (as indicated by wetness or discoloration). Not great enough to form drops.
CLASS II--Leakage of fluid great enough to form drops but not enough to cause drops to drip from item being
CLASS III--Leakage of fluid great enough to form drops that fall from the item being checked/inspected.
Water may enter the engine exhaust system when washing the vehicle. To prevent this occurrence, tape
the exhaust outlets before washing the vehicle, or operate the engine while washing. Care must also be
taken to prevent water from entering the personnel heater exhaust tube or auxiliary engine exhaust by
covering the exhaust outlets with tape or cap. Do not use high pressure hoses inside the hull.
Unwashed Vehicle. The driver or crew should present the vehicle for scheduled preventive maintenance services in a reasonably
clean condition. That is, it should be dry and not caked with mud to such an extent as to seriously hamper inspection and service.
However, washing of the vehicle should be avoided immediately prior to an inspection, since certain types of defects such as
loose parts and oil leaks may not be noticeable immediately after washing.
Plates. Nameplates, caution plates, and instruction plates found dirty or corroded should be thoroughly cleaned and heavily
coated with clear lacquer. Refer to TM 43-0139.
Services. Unit Maintenance services are defined by, and restricted to, the following general procedures:
Adjust. Make all necessary adjustments in accordance with instructions contained herein.
Special lubrication. Special lubrication supplies either to lubrication operations that do not appear in TM 9-2350-
256-10, or to items that do appear, but which should be performed in connection with the maintenance operations.
3. Service. Servicing usually consists of performing special operations, such as replenishing battery water, draining and
refilling units with oil, and changing the oil filters, fuel filters, and air cleaner filters.
4. Tighten. Tighten all units to torque specified herein or, if not specified, tighten to accepted practices. Use a torque
wrench where specified. Do not over tighten, as this may strip threads or cause distortion. Tightening includes the
correct installation of lockwashers, nuts lockwire, or cotter pins to secure the tightened nut or bolt in place.
Special Conditions. When conditions make it difficult to perform the complete preventive maintenance procedure on the vehicle
at one time, the procedure can be handled in sections. Plan to complete all operations within the week, if possible. All available
time must be utilized, if necessary, to assure that maintenance operations are completed.
Operation under adverse conditions, such as extreme temperatures, dust, or mud may require more frequent services. Comman-
ders are authorized to reduce the intervals between preventive maintenance services whenever conditions warrant.
When mileage is accumulated rapidly, the appropriate preventive maintenance services will be performed at the commander's