TM-9-2815-220-34 Direct Support Manual for AVDS-1790-2C and AVDS-1790-2D Engines Download
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ments and contains a chamber for collecting water. The two outer elements are coalescer elements and will remove emulsified water that has passed through the primary filter. The center element is a fuel filter element. The water removed from the fuel is automatically drained from the filter hous- ing. Two water sensing probes are located in the filter housing. When the water level reaches the upper probe, an electrical circuit is completed, a FUEL/WATER SEPARATOR SOLENOID WATER DRAIN . . -.. �4 . ._. TM 9-2815-220-34 solenoid valve opens and allows the water to drain. The valve closes when the water level reaches the lower probe. A drain cock is installed so the fueV water separator may be drained manualJy. The unit provides moisture-free and uncontaminated fuel to the injection pump. Both the primary ter and the fueVwater separator filter incorporate top mounted bleeder valves to assist in the removal of air from the fuel system. FUEL RETURN TUBE NO. 2R NO. 3R NO. 4R NO. SR PRIMARY FUEL FILTER CONSTANT FUEL BLEED 0.042 IN. ORIFICE FUEL RETURN TUBE TA265616 I Figure J.J 1.1. Main . el ystem - schematic diagram, Model AVDS·1790·2Dll only. f Fuel Cittoff Solenoid. An electrically operated fuel cutoff solenoid is mounted in the fuel injection pump. The solenoid is normally oפn. A switch in the vehicle driver's compartment actuates the cir· cuit to close the solenoid. Closing the solenoid cuts off fuel delivery om the fuel injection pump and stops the engine. A manually operated override shutoff is provided to permit stopping the engine in the event of an electrical failure. g. Fuel Return Check Valve. A fuel retu check valve (fig. 1·11 and fig. 1-11.1) is installed between the fuel injection pump fuel retu outlet and the fuel retu hose assembly. The valv e prevents fuel flowing back to the injection pump when the fuel supply is closed. Change 3 1·17