TM-9-2520-254-34 Direct Support for M113 TX100-1 Transmission 2520-00-066-4240 Download

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Section II. OPERATION OF HYDRAULIC SYSTEM 2-12. Hydraulic Schematics a. Full and Partial Schematics. A schematic diagram of the entire hydraulic system is illustrated in figure 2-2. Eight partial schematics in color (fig. 2-3 through 2-10) illustrate the operation of the hydraulic system under various conditions ex- plained in paragraphs 2-14 through 2-21. b. Valve Positions. (1) In the partial schematics (fig. 2-3 through 2-10). valves and other moving parts are shown in their proper positions for the conditions illustrated. Some valves will be at either one extreme or the other of their movement, while others are at some intermediate position. Thus, those at intermediate positions show only the approximate degree of movement under certain conditions. (2) It must be remembered that input speed, output speed. throttle opening, selector position, and oil temperature and viscosity will affect the degree of movement and positions of certain valves. c. Colors Indicate Hydraulic Circuits. Separate colors or color combinations indicate each hydraulic circuit. Color blocks on the partial schematics identify each circuit. Areas not colored are usually filled with oil which is neither flowing nor under pressure. Such areas are inactive, contribute nothing to hydraulic action, and may be disregarded. 2-13. Torque Converter or Lockup Drive The torque converter and lockup clutch must be considered as part of the hydraulic system since both require oil for operation. Therefore, in all explanations of transmission operation, keep in mind that the input drive may be direct (through the applied lockup clutch) or hydraulic (through the torque converter). These terms are reduced to “lockup” and “converter” operation in the ex- planations which follows. 2-14. Hydraulic System — Neutral Operation a. Main Pressure Circuit (red—fig. 2-3). (1) Engine idling. Figure 2-3 illustrates neutral operation of the transmission while the engine is idling and the engine throttle is closed. The transmission is in converter operation. 2-7