0314079 JOHNSON WATER TUBE, Return, long

SCHEMATIC OF FUEL SYSTEM
1. Fuel transfer pump inlet line. 2. Fuel priming pump. 3. Fuel passage. 4. Fuel return line. 5. Fuel tank. 6. Fuel transfer pump outlet line. 7. Fuel transfer pump. 8. Fuel filter housing. 9. Fuel injection pump housing.There is one fuel injection pump and one fuel injection valve for each cylinder. The fuel injection pumps are located in the fuel injection pump housing in the Vee of the engine. The fuel injection valves are located in the precombustion chambers in the cylinder heads.When the engine is running, fuel is pulled from fuel tank (5) through fuel transfer pump inlet line (1) by fuel transfer pump (7). The fuel is then pushed to fuel filter housing (8). Only the fuel needed goes through the fuel filters. The extra fuel goes to fuel control valve (11). The fuel from the fuel filters goes to the fuel injection pump housing (9). A passage in the housing gives fuel to each fuel injection pump. Individual fuel lines carry fuel from the fuel injection pumps to each cylinder.
FUEL FLOW THROUGH FUEL CONTROL VALVE (ENGINE RUNNING)
1. Fuel transfer pump inlet line. 2. Fuel priming pump. 3. Fuel passage. 6. Fuel transfer pump outlet line. 8. Fuel filter housing. 10. Fuel passage. 11. Fuel control valve. 13. Fuel passage.Fuel control valve (11) controls the pressure of the fuel in the fuel system. When the fuel system is at maximum pressure, fuel control valve (11) moves and the extra fuel not needed by the engine is bypassed. A part of the bypassed fuel goes back to the inlet of the fuel transfer pump and the rest goes through fuel passage (10) and returns to the fuel tank. Any air in the fuel filter housing goes around the grooves in fuel control valve (11) to fuel passage (10) and to the fuel tank.Fuel transfer pump (7) is located on the front, right hand side of the accessory drive housing. The pump is driven from the front of the oil pump drive gear.Fuel priming pump (2) is located on the top of the fuel filter housing. The fuel priming pump is used to vent air from the fuel system and to fill the fuel filter housing with fuel after the filters have been changed.
SUCTION STROKE OF PRIMING PUMP
1. Fuel transfer pump inlet line. 2. Fuel priming pump. 3. Fuel passage. 6. Fuel transfer pump outlet line. 8. Fuel filter housing. 10. Fuel passage. 11. Fuel control valve. 12. Spring. 13. Fuel passage.When the handle for the priming pump is pulled out (suction stroke), fuel control valve (11) moves toward fuel priming pump (2). This permits fuel from line (1) to flow into fuel priming pump (2).When the handle for the fuel priming pump is pushed in (pressure stroke), the force of fuel pressure and spring (12) causes fuel control valve (11) to move away from fuel priming pump (2). With fuel control valve (11) in this position, fuel passage (3) from line (1) is closed and fuel from the priming pump goes through fuel passage (13) to fuel filter housing (8). Air in the fuel system goes through fuel passage (10) and back to the fuel tank.
PRESSURE STROKE OF PRIMING PUMP
1. Fuel transfer pump inlet line. 2. Fuel priming pump. 3. Fuel passage. 6. Fuel transfer pump outlet line. 8. Fuel filter housing. 10. Fuel passage. 11. Fuel control valve. 12. Spring. 13. Fuel passage.Duplex Fuel Filter System
The duplex fuel filter system makes it possible to change elements for the fuel filters while the engine is running at any speed.During normal operation, the selector lever (1) should be in the "Main Filter Run-Aux. Off" position. The fuel then will be cleaned by the elements of the main filter which are located in the right side of the filter housing. The two elements of the auxiliary filter are located in the left side of the housing.
DUPLEX FUEL FILTER
1. Selector lever. 2. Priming pump.When the gauge for fuel pressure shows indication of minimum pressure of 20 psi (140 kPa) the main elements must be changed. While the main elements are being changed, the fuel must be cleaned by the two elements of the auxiliary filter.Explanation of flow, with the engine running, for the selector lever positions is as follows: AUX. VENT-MAIN RUNAny air in the auxiliary filter will go back to the fuel tank while the main filters will filter the diesel fuel. AUX. FILTER RUN-MAIN OFFThe auxiliary elements now filter the diesel fuel instead of the main elements. MAIN VENT-AUX. RUNWhile the auxiliary elements filter the fuel, the main filter housing will fill with fuel. MAIN FILTER RUN-AUX. OFFThe main filters will now be filtering the fuel. BOTH FILTERS RUNThis will permit more running time when both filter systems are almost to a condition of restriction as shown by the fuel pressure gauge.Fuel Injection Pumps
Fuel enters the fuel injection pump housing through fuel passage (6) and enters the fuel injection pump body through inlet port (2). Pump plunger (3) and lifter (7) are lifted by lobes on camshaft (8) and always make a full stroke. Each pump measures the amount of fuel to be injected into its respective cylinder and forces the fuel out the fuel injection valve.The quantity of fuel sent to the fuel injection valve is changed by the rotation of the pump plunger in the barrel. The pump plunger is turned by the governor action through fuel rack (5). The fuel rack turns gear segment (4) on the bottom of the pump plunger.
FUEL INJECTION PUMP
1. Pump. 2. Inlet port. 3. Pump plunger. 4. Gear segment. 5. Fuel rack. 6. Fuel passage. 7. Lifter. 8. Camshaft.Fuel Injection Valve
FUEL INJECTION VALVE CROSS SECTION
1. Fuel injection line. 2. Nut. 3. Body. 4. Nozzle assembly.High pressure fuel from the fuel injection pumps is moved through the fuel injection lines to the fuel injection valves. As high pressure fuel enters the nozzle assembly, the check valve in the nozzle opens and permits the fuel to enter the