C6.6 Marine Generator Set Caterpillar

Show/hide table

Contact with high pressure fuel may cause fluid penetration and burn hazards. High pressure fuel spray may cause a fire hazard. Failure to follow these inspection, maintenance and service instructions may cause personal injury or death.

Refer to the Operation and Maintenance Manual, "General Hazard Information and High Pressure Fuel Lines" before adjustments and repairs are performed.

Note: Refer to Systems Operation, "Cleanliness of Fuel System Components" for detailed information on the standards of cleanliness that must be observed during ALL work on the fuel system.

Ensure that all adjustments and repairs are performed by authorized personnel that have had the correct training.

If air enters the fuel system, the air must be purged from the fuel system before the engine can be started. Air can enter the fuel system when the following events occur:

• The fuel tank is empty or the fuel tank has been partially drained.

• The low pressure fuel lines are disconnected.

• A leak exists in the low pressure fuel system.

• The fuel filter has been replaced.

Priming a Single Filter System

Use the following procedures in order to remove air from the fuel system:

1. The engine can have the ability to auto start. Ensure that the power supply is isolated before any service or repair is performed.

2. Ensure that the fuel system is in working order. Check that the fuel supply valve (if equipped) is in the "ON" position.

Show/hide table



Illustration 1	g01619777
Typical example

3. Loosen the vent screw (1). Operate the fuel priming pump (2). Operate the pump until all the air is removed from the filter.

4. Tighten the vent screw to a torque of 6 N·m (4 lb ft).

5. Operate the fuel priming pump (1) until a strong pressure is felt on the fuel priming pump.

6. Operate the engine starter and crank the engine. After the engine has started, operate the engine for five minutes without load, immediately after air has been removed from the fuel system.

   Note: Operating the engine for this period of time will help ensure that the fuel system is free of air.

   Do not loosen the high pressure fuel line in order to purge air from the fuel system. This procedure is not required.

   After the engine has stopped, you must wait for 60 seconds in order to allow the fuel pressure to be purged from the high pressure fuel lines before any service or repair is performed on the engine fuel lines. If necessary, perform minor adjustments. Repair any leaks from the low pressure fuel system and from the cooling, lubrication or air systems. Replace any high pressure fuel line that has leaked. Refer to Disassembly and assembly Manual, "Fuel Injection Lines - Install".

   If you inspect the engine in operation, always use the proper inspection procedure in order to avoid a fluid penetration hazard. Refer to Operation and Maintenance Manual, "General hazard Information".

7. If you have ensured that the air has been removed from the fuel system and the engine fails to start refer to Troubleshooting, "Engine Cranks but Will Not Start".

Priming a Duplex Filter System

Show/hide table

Contact with high pressure fuel may cause fluid penetration and burn hazards. High pressure fuel spray may cause a fire hazard. Failure to follow these inspection, maintenance and service instructions may cause personal injury or death.

Refer to the Operation and Maintenance Manual, "General Hazard Information and High Pressure Fuel Lines" before adjustments and repairs are performed.

Note: Refer to Testing and Adjusting Manual, "Cleanliness of Fuel System Components" for detailed information on the standards of cleanliness that must be observed during ALL work on the fuel system.

Ensure that all adjustments and repairs are performed by authorized personnel that have had the correct training.

If air enters the fuel system, the air must be purged from the fuel system before the engine can be started. Air can enter the fuel system when the following events occur:

• The fuel tank is empty or the fuel tank has been partially drained.

• The low pressure fuel lines are disconnected.

• A leak exists in the low pressure fuel system.

• The fuel filter has been replaced.

Priming the Duplex Fuel Filters with the Engine Stopped

Note: The engine can have the ability to auto start. Ensure that the power supply is isolated before any service or repair is performed.

Use the following procedures in order to remove air from the fuel system:

Illustration 2	g01627770
Typical example

• (A) The fuel flow is to the left hand fuel filter.

• (B) The fuel flow is to both fuel filters.

• (C) The fuel flow is to the right hand fuel filter.

Illustration 3	g01704626
Typical example

• (A) The fuel flow is to the left hand fuel filter.

• (B) The fuel flow is to both fuel filters.

• (C) The fuel flow is to the right hand fuel filter.

Commissioning procedure

Use the following procedure in order to remove air from both fuel filters.

Duplex Fuel Filters

1. The engine can have the ability to auto start. Ensure that the power supply is isolated before any service or repair is performed.

Show/hide table



Illustration 4	g01704695
Secondary fuel filters

2. Ensure that the fuel system is in working order. Check that the fuel supply valve (if equipped) is in the "ON" position.

3. Ensure that the control levers are in position B. Refer to illustration 2 and 3.

4. Loosen both the vent screws (1) on the secondary fuel filter.

Show/hide table



Illustration 5	g01704793
Typical example

5. Unlock the fuel priming pump by turning the handle (2) counterclockwise.

6. Operate the fuel priming pump in order to remove the air from the fuel filters. Operate the hand priming pump until fuel free from air flows from the vent screws.

7. Tighten the vent screws securely.

8. Operate the hand priming pump until a strong pressure is felt on the pump. Push the priming pump plunger inward and tighten the plunger by hand. Drain the tray that is below the filters.

Note: Do not loosen the high pressure fuel lines in order to purge air from the system. This procedure is not required.

9. The engine fuel system should now be primed and the engine should now be able to start.

10. Operate the engine starter and crank the engine. After the engine has started, operate the engine for a minimum of five minutes without load, immediately after air has been removed from the fuel system.

    Note: Operating the engine for this period of time will help ensure that the fuel system is free of air.

11. Select the required position for the control levers on the primary filters and the secondary filters.

12. If you have ensured that the air has been removed from the fuel system and the engine fails to start refer to Troubleshooting, "Engine Cranks but Will Not Start".

After the engine has stopped, you must wait for 60 seconds in order to allow the fuel pressure to be purged from the high pressure fuel lines before any service or repair is performed on the engine fuel lines. If necessary, perform minor adjustments. Repair any leaks from the low pressure fuel system and from the cooling, lubrication or air systems. Replace any high pressure fuel line that has leaked. Refer to Disassembly and assembly Manual, "Fuel Injection Lines - Install".

If you inspect the engine in operation, always use the proper inspection procedure in order to avoid a fluid penetration hazard. Refer to Operation and Maintenance Manual, "General hazard Information".

Priming a Duplex Fuel Filter with the Engine in Operation

Primary Filter

1. Both the primary fuel filter and the secondary fuel filters must be replaced at the same time.

2. After new filters have been installed the fuel system will need to be purged.

3. Do not remove the vent screws on the primary fuel filter.

Note: The fuel system will be pressurized and the opening of a vent screw will allow fuel that is under pressure to escape.

4. Slowly rotate the control lever on the primary fuel filter toward position B.

5. Open the vent screw on the secondary fuel filter that is in operation. Ensure that the vent screw on the secondary fuel filter is covered with a soft cloth.

6. The opening of the vent screw and the rotation of the control lever must be performed simultaneously. Removal of the air from the filter will take a short period of time. Tighten the vent screw securely.

Note: Position B will allow the flow of fuel to both filters.

7. Rotate the control lever to the required operating position.

8. Prime the secondary filter.

Priming the Secondary Filter

1. Both the secondary fuel filter and the primary fuel filters must be replaced at the same time.

2. Loosen vent screw on the new secondary filter that has been replaced.

3. Slowly rotate the control lever on the secondary fuel filter toward position B. During this process, the fuel will escape from the loosened vent screw. Removal of the air from the filter will take a short period of time.

4. Tighten the vent screw when fuel free from air flows from the vent screws. Tighten the vent screw securely.

Note: Position B will allow the flow of fuel to both filters.

5. Rotate the control lever to the required position.

6. Drain the tray below the filters.