Cummins ISX11.9 CM2250 – Service Manual 006-060   Fuel Rail

WARNING  When using a steam cleaner, wear safety glasses or a face shield, as well as protective clothing. Hot steam can cause serious personal injury.

WARNING  Wear appropriate eye and face protection when using compressed air. Flying debris and dirt can cause personal injury.

CAUTION  Clean all fittings before disassembly. Dirt or contaminants can damage the fuel system.

Before servicing any fuel system components, (such as fuel lines, fuel pump, injectors, etc.), which would expose the fuel system or internal engine component to potential contaminants prior to disassembly, clean the fittings, mounting hardware, and the area around the component to be removed. Dirt or contaminants can be introduced into the fuel system and engine if the surrounding areas are not cleaned, resulting in damage to the fuel system and engine. Refer to Procedure 000-009 in Section 0.

Clean the injector supply line connections and mating components with contact cleaner, Part Number 3824510 or equivalent.

To prevent damage from debris and contamination, cover, cap, or plug any openings as soon as possible when servicing the fuel system.  Caps and plugs can be found in Clean Care Kit, Part Number 4919073.

WARNING  Normal engine operation creates highly pressurized fuel in the fuel line which will remain in the fuel line after engine shutdown. Never open the fuel system when the engine is operating. Before servicing the fuel system, always loosen the pump to rail fuel line at the rail to vent the pressure. Keep hands clear of the line when loosening. High pressure fuel spray can penetrate the skin, resulting in serious personal injury or death.

WARNING  When servicing the engine do not use the starting motor to rotate engine with a high pressure fuel system joint open.   Rotating the engine can create highly pressurized fuel in the fuel system.  High-pressure fuel spray can penetrate the skin, resulting in serious personal injury or death.

Before servicing the fuel system, loosen the pump to rail line at the rail to vent the fuel pressure.

Keep hands clear of the line when loosening the fuel rail nut.

Tighten the fuel rail nut.

NOTE: A machined slot in this fitting directs the fuel spray toward the inboard side of the fuel rail.

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

WARNING  Fuel is flammable. Keep all cigarettes, flames, pilot lights, arcing equipment, and switches out of the work area and areas sharing ventilation to reduce the possibility of sever personal injury or death when working on the fuel system.

WARNING  The pressure of the fuel in the line is sufficient to penetrate the skin and cause serious personal injury. Wear gloves and protective clothing.

• Disconnect the batteries. Refer to the OEM service manual.
• Disconnect the fuel pressure sensor from the engine wiring harness. Refer to Procedure 019-115 in Section 19.
• Remove the crankcase breather. Refer to Procedure 003-001 in Section 3.
• Remove the crankcase breather bracket. Refer to Procedure 003-027 in Section 3.
• Remove the high-pressure fuel lines from the fuel rail. Refer to Procedure 006-051 in Section 6.
• Remove the fuel drain line from the fuel pressure relief valve. Refer to Procedure 006-013 in Section 6.

Remove the four capscrews that secure the fuel rail to the cylinder head.

Remove the fuel rail.

CAUTION  Internal passages of the fuel rail may only be cleaned with contact cleaner, Part Number 3824510 or equivalent. Do not use a parts washer to clean the fuel rail. Dirt and contaminants can damage the fuel system.

Clean the fuel rail and mating components with contact cleaner, Part Number 3824510 or equivalent.

Inspect the fuel rail threads for damage.

Inspect the seating surface of the injector supply line joint. If damage is found, replace the fuel rail.

Install the fuel rail. Follow the proper sequence provided below to make sure the high-pressure fuel lines are properly aligned and to avoid excessive strain on the supply lines.

• Install the fuel rail capscrews finger-tight.
• Install the injector supply lines finger-tight.
• Tighten the injector supply tube nuts at the fuel connector retaining nut then the fuel rail. Tighten the injector supply lines in the following order: Cylinder 1, 6, 2, 3, 4, and 5.

• Install the pump to rail line finger-tight.
• Install the pump to rail line clamp finger-tight.
• Tighten the injector supply tube nut on the pump to rail line at the fuel pump then the fuel rail.

• Tighten the pump to rail line clamp capscrews.

• Tighten the four fuel rail capscrews.

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

• Install the crankcase breather bracket. Refer to Procedure 003-027 in Section 3.
• Install the crankcase breather. Refer to Procedure 003-001 in Section 3.
• Install the fuel drain line from the fuel pressure relief valve. Refer to Procedure 006-013 in Section 6.
• Install the fuel pressure sensor to the engine wiring harness.Refer to Procedure 019-115 in Section 19.
• Connect the batteries. Refer to the OEM service manual.
• Operate the engine and check for leaks.