Any time the fuel flow is broken and air is allowed to get into the fuel system, the fuel system must be primed. If air is left in the lines, the fuel system may become air bound, resulting in inability to start the diesel engine or the mis-firing of one or more cylinders.
When Equipped With Diesel Engine Electric Motor: When the engine is equipped with direct electric starting, a fuel priming pump is used to prime the system. To prime the system proceed as follows:
- 1. Check to see that the diesel fuel line valve is open.
- 2. Move the accelerator to the shut-off position so the fuel will flow through the pumps.
- 3. Open the fuel filter vent valve (2) and loosen the fuel injection valve line nuts (3).
- 4. Loosen the knob of the fuel priming pump (1).
- 5. Operate the pump plunger in and out until the flow of fuel from the fuel filter vent valve drain tube (4) becomes continuous and contains no air bubbles.
PRIMING THE FUEL SYSTEM
1-Fuel priming pump. 2-Fuel filter vent valve. 3-Fuel injection line nut. 4-Fuel filter vent valve drain tube.
- 6. When the flow of fuel from the drain tube and lines is continuous and contains no air bubbles, close the vent valve and tighten the line nuts.
- 7. Operate the fuel priming pump plunger in and out until the fuel pressure gauge indicator registers in the NORMAL (green) range.
- 8. Tighten the knob of the fuel priming pump to its original position.
When Equipped With Gasoline Starting Engine: Priming the fuel system will allow the fuel transfer pump to force air and fuel through the fuel filters and the fuel injection pumps if the engine is level. Prime the system as follows:
- 1. Check to see that the diesel fuel line valve is open.
- 2. Move the accelerator to the shut-off position so the fuel will flow through the pumps.
- 3. Move the compression release lever to the START position.
- 4. Start the starting engine and engage the starter pinion and clutch. Allow the starting engine to crank the diesel engine at starting engine low idle speed.
- 5. Open the fuel filter vent valve, and loosen the fuel injection line nuts. When the flow of fuel from the fuel filter vent valve drain tube and lines is continuous and contains no air bubbles, close the vent valve and tighten the line nuts.