Cummins ISX11.9 CM2250 – Service Manual 006-051   Injector Supply Lines (High Pressure)

Check the fuel pump to rail connection at the pump and rail (1).

Check the cylinder head and rail connections (2).

Check the fuel pump to rail line clamps.

NOTE: The nuts must be properly tightened or an external fuel leak can result, causing poor engine performance. A torque wrench must be used.

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.

• Disconnect the batteries. Refer to the OEM service manual.
• If necessary, remove the crankcase breather. Refer to Procedure 003-001 in Section 3.
• If necessary, remove the crankcase breather bracket. Refer to Procedure 003-027 in Section 3.

WARNING  Depending on the circumstance, diesel fuel is flammable. When inspecting or performing service or repairs on the fuel system, to reduce the possibility of fire and resulting severe personal injury, death or property damage, never smoke or allow sparks or flames (such as pilot lights, electrical switches, or welding equipment) in the work area.

CAUTION  Handle the fuel system components with care.  Handling damage to the fuel lines or fuel connectors can cause fuel leaks.

It is recommended that injector supply line be installed at the same location each time the injector supply line is removed. Mark or tag the injector supply line with the cylinder number to keep track of the correct position of each injector supply line.

Loosen the fuel lines at the fuel rail, fuel connector, and the fuel line at the high-pressure fuel pump.

Use a second wrench to prevent the fuel pump head outlet fitting from rotating while loosening the nut on the pump to rail line.

Remove the high-pressure fuel lines.

NOTE: Lines 2 and 3 are common, and lines 4, 5, and 6 are common.

Check for cracks, wear, or pinched areas. Replace the high-pressure lines, if necessary.

Inspect the ends of the high-pressure lines for damaged sealing surfaces. Replace the high-pressure lines, if necessary.

Before installing the injector supply lines, make sure the injector is properly seated into the injector bore (1) and the fuel connector (2) is fully and properly seated against the injector. Make sure the high-pressure connector retaining nut is tightened. Refer to Procedure 006-052 in Section 6.

It is recommended that the injector supply line be installed at the same location each time the injector supply line is removed.

WARNING  Depending on the circumstance, diesel fuel is flammable. When inspecting or performing service or repairs on the fuel system, to reduce the possibility of fire and resulting severe personal injury, death or property damage, never smoke or allow sparks or flames (such as pilot lights, electrical switches, or welding equipment) in the work area.

NOTE: If the fuel rail or multiple injector supply lines are installed during the service event, follow the installation sequence outlined in the fuel rail installation procedure. Refer to Procedure 006-060 in Section 6.

Tighten the pump to rail supply line at the pump and fuel rail (1).

Tighten the injector supply line nut(s) at the fuel connector.

Tighten the injector supply line nuts(s) at the fuel rail (2).

Tighten the pump to rail supply line clamps.

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.

• If necessary, install the crankcase breather bracket. Refer to Procedure 003-027 in Section 3.
• If necessary, install the crankcase breather. Refer to Procedure 003-001 in Section 3.
• Connect the batteries. Refer to the OEM service manual.
• Operate the engine and check for leaks.