TUBE AS-RADIATOR INLET 2W6642 - Caterpillar

Illustration 6 g02407018
Balance valve solenoid in closed position
(37) Path to balance valve actuator
(38) Vent
(39) Armature
(40) Path from the NRS mixerThe balance valve actuator is normally closed. The solenoid must be energized by the ECM to keep the balance valve actuator closed. The armature (1) in the balance valve solenoid is responsible for allowing or prohibiting the pressurizing of the entire balance valve system. The armature physically blocks the boost air from flowing to the balance valve actuator. The vent (2) is responsible for purging residual pressure from the balance valve system once the pressure is no longer needed. Without the vent, there would constantly be pressure on the balance valve actuator and not allow the actuator to close. When the charge air pressure supplied to the balance valve actuator exceeds a predetermined limit, the balance valve actuator will open. The actuator opening causes the turbocharger speed to decrease and protects the engine. Engine speed must be present for in order for the electrical current to command the balance valve solenoid to close. If the key is on but the engine is not running, the balance valve solenoid will remain open.
Illustration 7 g02407019
Balance valve solenoid in open position
(37) Path to balance valve actuator
(40) Path from the NRS mixerThe balance valve solenoid is activated to the open position by the ECM when the conditions of the performance map are met. Typical engine conditions are when the pressure difference between the two turbine paths becomes greater than desired. These conditions can occur during engine powering or engine braking (if applicable). When the balance valve solenoid is opened, the armature blocks the vent passage not allowing any leakage.Valve System Components
Illustration 8 g02407056
Valve system components
(41) Rocker arm
(42) Valve adjustment screw
(43) Rocker arm shaft
(44) Camshaft follower
(45) Camshaft
(46) Valve bridge
(47) Valve rotator
(48) Valve spring
(49) Valve
(50) Valve seatThe valve train controls the flow of inlet air into the cylinders and the flow of exhaust gases out of the cylinders during engine operation. Machined lobes on camshaft (45) are used to control the following aspects of valve function:
Height of valve lift
Timing of valve lift
Duration of valve liftThe crankshaft gear drives the camshaft gear through the front.Variable Valve Actuator (If Equipped)
The Intake Valve Actuation system (IVA) uses pressurized engine oil to delay the closing of the intake valves. The system is controlled by the ECM. The system contains the following components:Check Valve (53) - Pressurized engine oil flows to a rail inside the valve cover base. A check valve prevents oil from flowing from the rail back to the main oil gallery.Pressure Sensor (52) - A pressure sensor is threaded into the rail. The sensor converts the rail pressure into an electrical signal. The ECM monitors the signal to determine the pressure of the oil in the rail.Control Valve (51) - A control valve is threaded into the rail. The control valve contains a coil and a cartridge assembly. The cartridge assembly contains a spool. The spool is normally closed. When the spool is closed, the oil is contained in the