HARNESS AS 4592354 - Caterpillar

Gradual Right Turn
Illustration 2 g00290377
Steering and brake control valve (1) Circuit for clutch oil (2) Clutch spool for right steering (A) Secondary brake solenoids (G) Proportional valves (AA) Supply oil (BB) Brake pressure oil (CC) Left clutch oil (EE) Pilot signal oil for the brake (FF) Pilot signal oil for the clutch (LL) Drain oilControl Valve Operation for a Gradual Right Turn
Note: The steering clutch and the brake are not engaged. The control valve has proportional solenoid valves (G) which control the position of pressure reducing spools (4) in the control valve.As the operator begins to pull the right steering control lever, the pulse width modulated sensors send a signal to the ECM. This signal is sent in order to decrease the current going to proportional solenoid valve (G) for the right clutch.The decreased current causes a decrease in pilot oil pressure which causes reducing spool (4) to shift to the left. This shift exhausts the oil in the clutch circuit. When the oil is exhausted the clutch oil pressure is lowered.The current that goes to the solenoid for the proportional valve is dependent upon the position of the control lever. The solenoid sets the pilot oil pressure. The pressure in the clutch circuit is directly affected by the position of the control lever.When the control lever is pulled back the clutch pressure is reduced. When you pull back the control lever further, the clutch pressure is reduced until the pressure reaches zero kPa (psi) and the clutch is released. The machine will then make a gradual right turn.Sharp Right Turn
Illustration 3 g00290378
Steering and brake control valve (4) Right brake spool (A) Secondary brake solenoids (G) Proportional valves (AA) Supply oil (BB) Brake pressure oil (CC) Left clutch oil (EE) Pilot signal oil for the brake (FF) Pilot signal oil for the clutch (LL) Drain oilControl Valve Operation for a Sharp Right Turn
Note: The steering clutch is not engaged. The brake is engaged.The control valve has proportional solenoid valves (G) which control the position of pressure reducing spools (4) in the control valve. These spools adjust the clutch and brake pressure when the levers on the finger tip control are moved.In order to make a sharp right turn, the operator pulls the steering control lever backward all the way. During the first movement of the control lever, the clutch pressure is modulated to zero kPa (psi). This is the same pressure as a gradual right turn.As the operator continues to pull the control lever backward, the pulse width modulated sensors send a signal to the ECM. This signal decreases the current to the right proportional solenoid (G) for the brake. This decreases pilot oil pressure which causes reducing spool (4) to shift to the left. This shift to the left exhausts the oil in the right brake circuit which drops the brake pressure.The current that goes to the proportional solenoid valve is determined by the position of the control lever. The proportional