TM 5-3805-281-24-2
UNIT PREVENTIVE MAINTENANCE CHECKS AND SERVICES (PMCS)
A-1. GENERAL
Preventive Maintenance Checks and Services (PMCS) are performed to keep the Hydraulic Excavator in
operating condition. The checks are used to find, correct, or report problems. Pay attention to WARNING
and CAUTION statements. A WARNING means someone could be hurt. A CAUTION means equipment
could be damaged.
Once a week do Weekly PMCS. If Hydraulic Excavator has not been operated in a week, also do Before
PMCS at the same time.
Do Monthly PMCS once a month. If Hydraulic Excavator has not been operated in a month, also do After
PMCS at the same time.
If you are operating the Hydraulic Excavator for the first time, do your Weekly and Monthly PMCS the
first time you do your Before PMCS.
If you find something wrong when performing PMCS, fix it if you can using troubleshooting procedures
and/or maintenance procedures.
The right-hand column of the PMCS table lists conditions that make the Hydraulic Excavator not fully
mission capable. Write up items not fixed on DA Form 2404 for direct support maintenance. For further
information on how to use this form, see DA PAM 738-750.
A-2. LEAKAGE DEFINITION
CAUTION: Equipment operation is allowable with minor leakages (Class I or II) except for fuel
leaks. Of course, consideration must be given to the fluid capacity of the item or system being
checked. When in doubt, ask your supervisor.
When operating with Class I or II leaks, continue to check fluid levels as required in the PMCS.
Class III leaks should be reported immediately to your supervisor.
It is necessary to know how fluid leakage affects the status of the Hydraulic Excavator. The following are
definitions of the classes of leakage an operator or crewmember needs to know to be able to determine the
condition of the leak. Learn and then be familiar with them, and REMEMBER-WHEN IN DOUBT, ASK
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 checked.
CLASS III-Leakage of fluid great enough to form drops that fall from the item being checked.
