TM 5-3805-258-24-1POWER TRAINTRANSMISSION HYDRAULIC CONTROLSNeutralizer ValveWhen the left brake pedal is pushed, air pressure,from the brake system, moves neutralizer valve (12)against the force of its spring. The movement of valve(12) opens the chamber at the left end of pressuredifferential valve (14) to the reservoir through theneutralizer valve body. The force of the springs andthe oil pressure in the spring chamber of the pressuredifferential valve, move the valve to the left. Themovement of valve (14) opens the direction clutchcircuit to the reservoir through the right end of thevalve. The valve spool moves further to the left, untilthe flow of pump oil to the direction clutch is stopped.At this time, pressure differential valve (14) is in aposition to let the pressure increase in the directionclutch circuit, when the left brake pedal is released.Ratio Valve for Converter InletThe ratio valve (16) for the torque converter,controls the maximum pressure to the converter. ItsS Y S T E M S O P E R A T I O Nprimary purpose is to prevent damage to the convertercomponents when the engine is started with cold oil.The pressure to the torque converter, caused byrestrictions to flow, is felt against the left end of valvespool (16). This pressure pushes against the wholediameter of the valve spool.Pressure from the P1 clutch circuit is felt in theslug chamber of the valve spool. This pressure pushesagainst only the diameter of the slug.The pressure (on the left end of valve) needed tomove the valve to the right is less than the pressure(in slug chamber) needed to move the valve to theleft.When the inlet pressure to the torque convertergets to its maximum, the valve spool moves to theright. This lets the extra oil go to the reservoir. Whenthe pressures are again in balance, the valve movesback to the left.All oil, not used by the clutches goes to the ratiovalve for the torque converter.3-48
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