TM-9-2815-220-34 Direct Support Manual for AVDS-1790-2C and AVDS-1790-2D Engines Download
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TM 9-2815-220-34 MANUAL ORA!ll FUEL/I/ATER SEPARATOR SOLENOID I/ATER DRAIN TUBE • FUEL INJECTION \J· PUMP lLET HOSE FUEL BACKFLOW VALVE O (90 PSI RELIEF VALVE} NO. lR CONSTMT FUEL BLEED 0.042 l. OR!FltE FUEL RETURll TUBE 0 LEFT FUEL RETURll TUBE RIGHT FUEL NO. 6R RETURN TUBE TA265615I ure 1 ·I I. Mait1 fuel system - schematic diagram, models A l'DS-1790·ZCand A l'DS·l 790·2D. d. Fuel Purge System. A manually operated purge pump is provided in the vehicle operator's compartment and is used to clear the engine main fuel system and flame heater system of air, and fill them with fuel. Most of the purged air is removed through bleeder valves, located in the top of the primary fuel filter and the fuel/water separator filter. The rest of the air is forced through the main fuel tubes into the fuel retu lines and on to the vehicle fuel tanks. Water is removed from the sys- tem by a constant bleed orifice in the primary fuel filter and an automatic water drain in the fuel/ water separator filter. e. Fuel Filters (figs. 1-2 and 1-3). The replaceable element type primary fuel filter is mounted on the right front of the engine and is equipped with a constant bleed orifice and drain line which con- 1-16 Change 3 stantly removes a metered amount of fuel and re- turns it to the main fuel tank through the fuel injector nozzle drain lines. This continuous drain, from the bottom of the filter, remo, ves water in the free state that has been filtered from the fuel by the primary fuel filter element. The replaceable element fuel/water separator type filter is mounted on the left front of the engine. Fuel from the vehicle fuel tank passes through the primary filter before entering the engine fuel pump. The· pump delivers fuel to the fueVwater separator fil- ter and on to the fuel injection pup. Excess fuel provides pump cooling as it flows through the fuel injection pump hydraulic heads and is returned to the fuel tanks (figs. 1-11an�1-11.1) The fueVwater separator filter unit has three replaceable ele-