HOSE 3096994 - Caterpillar

Illustration 1 g00459692
Hydraulic valve locations (A) Speed clutch "A" (B) Speed clutch "B" (C) Speed clutch "C" (1) Number one speed clutch (2) Number two speed clutch (3) Number three speed clutch (F1) First direction clutch F1 (F2) Second forward direction clutch F2 (REV) Reverse direction clutch F1 (MC1) Modulating solenoid (MC2) Modulating solenoidThe transmission hydraulic control valve is mounted externally on the right hand side of the center housing of the transmission. The transmission hydraulic control performs the actual application and the actual release of the speed clutches and the direction clutches.The transmission hydraulic control contains twelve separate hydraulic valves. Eleven of the hydraulic valves are electronically controlled solenoid valves. Also, there is one regulating valve. Out of the eleven electronically controlled solenoid valves, there are nine solenoid valves that control the application of the six speed and three direction clutches. The remaining two solenoid valves are for modulating the engagement of the three direction clutches. Modulating solenoid (MC1) is for direction clutch (F1). Modulating solenoid (MC2) is for direction clutches (F2) and (R) .The transmission hydraulic control and the modulating solenoids are energized and controlled by the Electronic Transmission Control. This system receives a signal that is from the transmission control lever linkage and the foot-operated inching clutch control.A regulating valve that is located on the right side of the transmission hydraulic control is set at 1825 70 kPa (265 10 psi). The regulating valve maintains a constant oil pressure in the low pressure circuit of the machine. The low pressure circuits include the following circuits: transmission hydraulic control, lubrication of the transmission clutches, PTO control, service brake control and hydraulic oil cooler.Operation of the Regulator Valve
Illustration 2 g00459695
Regulator valveSupply oil that is present in passage (A) of regulator valve (2) is also connected to the clutch circuits at passage (B). This oil cannot escape until spool (5) has moved to the right. Oil enters the hollow spool through an opening and orifice plate (1). The oil that is passing through orifice plate (1) is filling the passage in spool (5). The oil pressure that is acting on the left side of spool (5) forces the spool to the right. Spool (5) moves against the opposing force of two springs (3) and shims (4). Shims (4) are used in order to make adjustments to the low pressure circuit. When spool (5) moves, any surplus oil that is required for the operation of clutches and modulating solenoids passes through passage (C). This oil is used for the lubrication and cooling circuits.Operation of the Clutch Valve
Illustration 3 g00459706
Clutch valveEach of the nine solenoid valves for the clutch circuits operate in an identical manner. However, the application of the direction clutches are modulated or proportionally controlled. These circuits allow the application and the release of the clutch circuits for the direction clutches to be cushioned. The