C . S e r v i c e . Operations required periodically to keep an item in proper operating condition, i.e., to clean
(includes decontaminate), to preserve, to drain, or to replenish fuel, Iubricants, chemical fluids, or gases.
d. A d j u s t . To maintain within prescribed limits, by bringing into proper or exact position, or besetting the
operating characteristics to the specified parameters.
e. Aline. To adjust specified variable elements of an item to bring about optimum or desired performance.
Calibrate. TO determine and cause corrections to be made or to be adjusted on instruments or test
measuring and diagnostic equipment used in precision measurement. Consists of comparison of two
instruments, one of which is a certified standard of known accuracy, to detect and adjust any discrepancy in the
accuracy of the instrument being compared.
g. Install . The act of emplacing, seating, or fixing into position an item, part, or module (component or
assembly) in a manner to allow the proper functioning of an equipment or system.
h. R e p l a c e. The act of substituting a serviceable like type part, a subassembly, or module (component or
assembly) for an unserviceable counterpart.
Repair. The application of maintenance services (inspect, test, service, adjust, aline, calibrate, or replace)
or other maintenance actions (welding, grinding, riveting, straightening, facing, remachining, or resurfacing) to
restore serviceability to an item by correcting specific damage, fault, malfunction, or failure in a part, subassembly,
module (component or assembly), end item, or system.
Overhaul. The maintenance effort (service/action) necessary to restore an item to a completely
serviceable operational condition as prescribed by maintenance standards in appropriate technical publications
(i.e., DMWR). Overhaul does not normally return an item to a like new condition.
k. R e b u i l d. Consists of those services/actions necessary for the restoration of unserviceable equipment to a
Iike new condition in accordance with original manufacturing standards. Rebuild is the highest degree of materiel
maintenance applied to Army equipment. The rebuild operation includes the act of returning to zero those age
measurements (hours/miles, etc.) considered in classifying Army equipment/components.
B - 4 . E x p l a n a t i o n o f C o l u m n s i n t h e M A C , S e c t i o n I l .
a. C o l u m n (1). Group N u m b e r. Column 1 lists function group code numbers which are assigned to identify
maintenance significant components, assemblies, subassemblies, and modules to their next higher assembly.
Column (2). Component/Assem bly. Column 2 contains the item names of components, assemblies,
subassemblies, and modules for which group numbers (column 1) are assigned and for which maintenance is
c. C o l u m n (3). M a i n t e n a n ce F u n c t i o n.
Column 3 lists the functions to be performed on items listed in
Column 2. (F
unction definitions are contained in paragraph A-3.)