TM-9-2815-220-24 Maintenance Manual for AVDS-1790-2CA AVDS-1790-DA and AVDS-1790-2DR Engines Download
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TM 9-2815-220-24 THEORY OF OPERATION 0004 00 WP 0004 00-17 Electrical Shutoff Manual Shutoff ENGINE COMPONENTS (Continued) Fuel Cutoff Solenoid: An electrically-operated fuel cutoff solenoid is contained within the fuel injection pump. The solenoid is normally open. A switch in the vehicle driver's compartment actuates the circuit to close the solenoid. Closing the solenoid shuts off fuel delivery from 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. Fuel Filters: Fuel flows from the vehicle fuel tanks through the primary fuel filter, backflow valve, engine- mounted fuel supply pump, fuel/water separator filter to the fuel injection pump where it passes through a final filter built into the pump. Excess fuel provides pump cooling as it flows through the fuel injection pump hydraulic heads and is returned to the fuel tanks. Primary Fuel Filter - The replaceable-element type primary fuel filter is mounted on the right front of the engine. It is equipped with a constant bleed orifice and drain line that removes a metered amount of fuel and returns it to the main fuel tank through the fuel injector nozzle drain lines. This continuous drain, from the bottom of the filter, removes water that has been filtered from the fuel by the primary fuel filter element. Fuel/Water Separator Filter - a replaceable-element type filter, it is mounted on the left front of the engine. A dual- purpose filter, the fuel/water separator filter first removes emulsified water from the fuel and then removes solid particles not trapped previously by the primary fuel filter. The fuel/water separator filter consists of two outer elements (coalescer elements for removing water) a center element, which is the final fuel filter (down to 5 microns), and a water collection chamber with two water-sensing electric probes.