Home » ISX11.9 CM2250 - Service Manual » Cummins ISX11.9 CM2250 – Service Manual 006-061   Fuel Pressure Relief Valve

Cummins ISX11.9 CM2250 – Service Manual 006-061   Fuel Pressure Relief Valve

General Information

TOC

Use the following procedure for details on testing the fuel pressure relief valve for excessive leakage. Refer to Procedure 005-236 in Section 5.

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Preparatory Steps

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 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.

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 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.

Torque Value:  65  n.m  [48 ft-lb]

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

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 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.

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Remove

TOC

Remove the fuel pressure relief valve.

Remove and discard the sealing washer.

A flat sealing washer is swaged into the inlet fitting bore during installation.

A special tool can be created to aid in its removal by grinding the short leg of a 1/8-inch or 3/16-inch Allen wrench, so that the wrench is no longer than 13-mm [1/2-in] long (measured from the outside of the long leg).

This tool acts as a mini heal bar to pry out the sealing washer without damaging the back of the hole.

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The high-pressure relief valve sealing washer must be replaced if the high-pressure relief valve is removed.

Use the modified Allen wrench to pry out the old sealing washer from the threaded hole in the fuel rail.

Considerable force is required to remove the sealing washer.

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Inspect for Reuse

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If the fuel pressure relief valve exhibits excessive leakage to drain, it must not be reused. Use the following procedure for instructions on measuring drain leakage. Refer to Procedure 005-236 in Section 5.

Inspect the high-pressure seal surface on the fuel pressure relief valve and in the fuel rail for damage. Do not reuse components if the high-pressure seal joint is damaged.

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Install

TOC

Install the fuel pressure relief valve, with a new sealing washer, using assembly lubricant, Part Number 3163087 or equivalent, on the threads.

Torque Value:

  1. 27 n.m   
    [239 in-lb]
  2. Rotate 90 degrees

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Finishing Steps

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 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 fuel drain line to the fuel rail pressure relief valve. Refer to Procedure 006-013 in Section 6.
  • Connect the batteries. Refer to the OEM service manual.
  • Operate engine and check for leaks.

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Last Modified:  16-Jun-2010