CARGO BED COVER (CBC) HMMWV, TYPE I
MAINTENANCE ALLOCATION CHART (MAC)
The Army Maintenance System MAC
This introduction provides a general explanation of all maintenance and repair functions authorized at
various maintenance levels under the standard Army Maintenance System concept.
The MAC (immediately following the introduction) designates overall authority and responsibility for the
performance of maintenance functions on the identified end item or component. The application of the
maintenance functions to the end item or component shall be consistent with the capacities and
capabilities of the designated maintenance levels, which are shown on the MAC in column (4) as:
Unit - includes two subcolumns, C (operator/crew) and O (unit) maintenance.
Direct Support - includes an F subcolumn.
General Support - includes an H subcolumn.
Depot - includes a D subcolumn.
The tools and test equipment requirements (immediately following the MAC) list the tools and test
equipment (both special tools and common tool sets) required for each maintenance function as
referenced from the MAC.
The remarks (immediately following the tools and test equipment requirements) contain supplemental
instructions and explanatory notes for a particular maintenance function.
Maintenance functions are limited to and are defined as follows:
1. Inspect. To determine the serviceability of an item by comparing its physical, mechanical, and/or
electrical characteristics with established standards through examination (e.g., by sight, sound, or
2. Test. To verify serviceability by measuring the mechanical, pneumatic, hydraulic, or electrical
characteristics of an item and comparing those characteristics with prescribed standards.
3. Service. Operations required periodically to keep an item in proper operating condition, i.e. to clean
(includes decontaminate, when required), to preserve, to drain, to paint, or to replenish fuel,
lubricants, chemical fluids, or gases.
4. Adjust. To maintain or regulate, within prescribed limits, by bringing into proper position, or by
setting the operating characteristics to specified parameters.
5. Align. To adjust specified variable elements of an item to bring about optimum or desired