SHAFT 1U3881 - Caterpillar

Introduction
For Specifications with illustrations, make reference to SPECIFICATIONS FOR 5.4" BORE 60° V8 VEHICULAR ENGINE, Form No. SENR7205. If the Specifications in Form SENR7205 are not the same as in the Systems Operation and the Testing and Adjusting, look at the printing date on the back cover of each book. Use the Specifications in the book with the latest date.Fuel System
FUEL SYSTEM SCHEMATIC
1. Fuel transfer pump. 2. Check valve. 3. Fuel injection pump. 4. Fuel filter. 5. Reservoir. 6. Fuel supply line. 7. Electric priming pump. 8. Fuel return line to tank. 9. Fuel filters. 10. Fuel filter bleed. 11. Injection pump bleed. 12. Bypass valve. 13. Switch. The fuel system shown is for the earlier engines. Even though some components on the later engines are not located the same as on the earlier engines, this schematic still applies. The 600 Series Tractors have a manually operated priming pump.Fuel is drawn from the fuel tank through the fuel supply line and fuel filter by the transfer pump. This pump is mounted on the fuel injection pump housing and is driven by a shaft connected to the fuel injection pump camshaft.A bypass valve, at the inlet side of the fuel filter, assures adequate pressure for the fuel system and allows excess fuel to be bypassed back to the fuel tank through a fuel return line.A fuel priming pump is used to fill the filter case, pressurize the fuel and assure that the system is free of air prior to starting the engine. A system of check valves allows fuel to be pumped past the fuel transfer pump when the priming pump is in use. As the filter and fuel injection pump passages are being filled with fuel from the priming pump, the fuel filter bleed on the filter housing can be opened to allow air to escape. The injection pump bleed valve can be used to allow any entrained air to escape from the individual fuel pumps and eliminate the need for loosening fuel line connections at the individual fuel pumps.Individual fuel injection lines carry fuel from the pumps to each cylinder. One section of line connects between the fuel injection pump and an adapter on the inward portion of the camshaft housing. Another section of line on the inside of the camshaft housing connects between the adapter and the top of the precombustion chamber.The fuel pump camshaft is driven by gears located inside a cover at the rear of the engine. An adjustable drive gear at the rear of the engine vee, drives a speed sensing, variable timing unit which in turn is coupled to the fuel pump camshaft through a sliding spline. This variable timing unit automatically provides retarded timing for easier starting and smooth low rpm operation. It will also advance timing as engine rpm increases to provide optimum engine operating efficiency.Fuel Injection Pump
Fuel enters the fuel injection pump housing through passage (6) and enters the fuel injection pump body through the inlet port (2). The