TM 9-4310-394-13
Section III. UNIT PREVENTIVE MAINTENANCE CHECKS
AND SERVICES (PMCS)
4-8. INTRODUCTION. Systematic, periodic, Preventive Maintenance Checks and Services (PMCS) are essential to
ensure that the air compressor unit is ready for operation at all times. The purpose of a preventive maintenance program
is to discover and correct defects and deficiencies before they can cause serious damage or complete failure of the
equipment. Any effective preventive maintenance program must begin with the indoctrination of operators to report all
unusual conditions noted during daily checks or actual operation to unit maintenance. All defects and deficiencies
discovered during maintenance inspections must be recorded, together with corrective action taken, on DA Form 2404
(Equipment Inspection and Maintenance Worksheet).
A schedule for unit preventive maintenance inspection and service should be established immediately after installation of
the air compressor unit. A quarterly interval, equal to three calendar months or 250 hours of operation (whichever occurs
first) is recommended for usual operating conditions. When operating under unusual conditions, such as a very dusty or
sandy environment, it may be necessary to reduce the interval to monthly or even less if conditions are extreme.
Table 4-1 lists the unit preventive maintenance checks and services that should be performed at quarterly (or otherwise
established) intervals. The PMCS items in the table have been arranged and numbered in a logical sequence to provide
for greater personnel efficiency and least amount of required maintenance downtime.
4-9. PMCS TABLE. Refer to Table 4-1. for the unit Preventive Maintenance Checks and Services required for the air
compressor unit. A description of the columns in the table is included in the following paragraphs.
a. Item Number Column. This column is a list of every check and service task in the PMCS.
They are numbered in logical order of performance regardless of the interval. This column is to be used as a source of
item numbers for the TM Number Column on DA Form 2404, Equipment Inspection and Maintenance Worksheet, in
recording results of PMCS.
b. Interval Column. This column is subdivided into three categories; M-Monthly, Q-Quarterly, and A-Annually. A
dot in the appropriate column signifies the interval at which a specific item needs to be checked or serviced.
c. Item To Be Inspected Column. This column provides the name of the item to be checked or serviced.
d. Procedures Column. This column describes the procedures to check or service an item. It includes all the
information required to perform the checks or services. It indicates tolerances where applicable and adjustment limits
where required.
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