Cummins ISX11.9 CM2250 – Service Manual 006-052   Fuel Connector (Head Mounted)

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.

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  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.

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 towards the inboard side of the fuel rail.

• 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.
• Remove the high-pressure fuel supply lines. Refer to Procedure 006-051 in Section 6.

Remove the fuel connector retaining nut.

Remove the fuel connector from the cylinder head.

Used fuel connectors must be installed with the same injector each time the fuel connector is removed. Mark or tag the fuel connector with the cylinder number to keep track of the correct position of each fuel connector.

A new high-pressure connector must be installed if a new injector is being installed.

Inspect the fuel connector bore for debris. If debris is found, replace the fuel connector and inspect the connecting injector supply line.

Inspect the outlet sealing surface of the high-pressure connector for wear, an uneven seating surface, or signs of leakage. Replace the high-pressure connector if burrs, wear, discoloration due to excessive heat, or deformation is observed.  If the high-pressure connector is worn or damaged, remove the injector and inspect the mating surface. Refer to Procedure 006-026 in Section 6.

Check the o-ring for tearing or deterioration.

When a high-pressure fuel leak is present, small lines or cuts in the connector will be eroded into the seating surface.

The high-pressure connector and injector must be replaced when this damage is observed.

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.

CAUTION  Use of hammers or other tools to install high-pressure connectors may result in fuel leaks. High-pressure connectors should be installed by hand to avoid damage to the sealing surface of the connector.

NOTE: If a new injector has been installed, a new fuel connector must be used.

NOTE: If the injector was removed along with the high-pressure fuel connector, the installation steps in the following procedure must be followed. Refer to Procedure 006-026 in Section 6.

Lubricate the threads on the fuel connector retaining nut with clean engine oil.

Align the fuel connector guide pin with the slot in the cylinder head at the 12-o’clock position. To prevent damage to the fuel connector, push downward on the threaded end of the fuel connector to lift the fuel connector tip and help the connector tip seat properly against the injector.

Tighten the fuel connector retaining nut.

The high-pressure fuel connector must be properly tightened or an internal fuel leak can result, causing poor engine performance. A torque wrench must be used.

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.
• Install the high-pressure fuel supply lines. Refer to Procedure 006-051 in Section 6.
• Connect the batteries. Refer to the OEM service manual.
• Operate the engine and check for leaks.