TB-9-2510-251-13 HMMWV Operator and Field Maintenance, Installation & Parts Add-On-Armor Air Conditioning Download
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TB 9-2510-251-13 B-1 APPENDIX B MAINTENANCE ALLOCATION CHART (MAC) Section I. INTRODUCTION B-1 THE ARMY MAINTENANCE SYSTEM MAC. a. This introduction provides a general explanation of all maintenance and repair functions authorized at the two maintenance levels under the Two-Level Maintenance System Concept. b. This MAC 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, which are shown on the MAC in Column (4) as: Field: Includes two columns, Unit maintenance and Direct Support maintenance. The Unit maintenance column is divided again into two more subcolumns, C for Operator or Crew and O for Unit maintenance. Sustainment: Includes two subcolumns, General Support (H) and Depot (D). c. The tools and test equipment requirements list the tools and test equipment (both special tools and common tool sets) required for each maintenance function as referenced from the MAC. d. The remarks contain supplemental instructions and explanatory notes for a particular maintenance function. B-2 MAINTENANCE FUNCTIONS. Maintenance functions are limited to and defined as follows: a. 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 feel). This includes scheduled inspection and gagings and evaluation of cannon tubes. b. Test. To verify serviceability by measuring the mechanical, pneumatic, hydraulic, or electrical characteristics of an item and comparing those characteristics with prescribed standards on a scheduled basis, i.e., load testing of lift devices and hydrostatic testing of pressure hoses. c. 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. This includes scheduled exercising and purging of recoil mechanisms. The following are examples of service functions: 1) Unpack. To remove from packing box for service or when required for the performance of maintenance operations. 2) Repack. To return item to packing box after service and other maintenance operations. 3) Clean. To rid the item of contamination. 4) Touch up. To spot paint scratched or blistered surfaces. 5) Mark. To restore obliterated identification. d. Adjust. To maintain or regulate, within prescribed limits, by bringing into proper or exact position, or by setting the operating characteristics to specified parameters. e. Align. To adjust specified variable elements of an item to bring about optimum or desired performance. f. 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 comparisons of two instruments, one of which is a certified standard of known accuracy; to detect and adjust any discrepancy in the accuracy o the instrument being compared.