Series 55 – Section 2.20 Internal High Pressure Fuel Line

Section 2.20
Internal High Pressure Fuel Line

The internal high pressure fuel line supplies fuel from the external high pressure fuel line to the injector nozzle holder assembly located inside the cylinder head. See Figure "Internal High Pressure Fuel Line" .‪

1.Cylinder Block‪	5.Injector Nozzle‪
2.Cylinder Head‪	6.Internal Injector Fuel Line‪
3.Nozzle Hold Down Crab‪	7.High Pressure Fuel Line‪
4.M10 Bolt‪	8.Electronic Unit Pump‪

Figure 1. Internal High Pressure Fuel Line

Section 2.20.1
Repair or Replacement of Internal High Pressure Fuel Line

To determine whether repair is possible or replacement is necessary, perform the following procedure. See Figure "Flowchart for Repair or Replacement of Internal High Pressure Fuel Line" .‪

Figure 2. Flowchart for Repair or Replacement of Internal High Pressure Fuel Line

Section 2.20.2
Removal of Internal High Pressure Fuel Line

Pre-cleaning is not necessary. Remove the internal high pressure fuel line as follows:‪

1. Remove intake manifold. Refer to "6.3.2 Removal of Intake Manifold" .
2. Remove the external high pressure fuel line. Refer to "2.19.2 Removal of External High Pressure Fuel Line" .
3. Remove the internal high pressure fuel line retaining nut from the cylinder head. See Figure "Removal of Internal High Pressure Fuel Line" .
4. Remove the internal fuel line.
   

   1.Retaining Nut‪	3.Cylinder Head‪
   2.Internal Fuel Line‪	‪

   Figure 3. Removal of Internal High Pressure Fuel Line

Section 2.20.2.1
Inspection of Internal High Pressure Fuel Line

Inspect the internal high pressure fuel line as follows:‪

1. Inspect the internal high pressure fuel line for damage:
   1. Check the internal high pressure fuel line for stress cracks, gouge marks, or bends.
   2. If any damage is found, replace the internal fuel line.
2. Inspect the internal high pressure line retaining nuts:
   1. Check for damaged threads.
   2. If these are detected, replace the nut.

Section 2.20.3
Installation of Internal High Pressure Fuel Line

Install the internal high pressure fuel line as follows: See Figure "Installation of Internal High Pressure Fuel Line" .‪

1. Insert the internal high pressure fuel line in the cylinder head.
2. Install internal high pressure fuel line retaining nuts.
3. Torque retaining nut to 34-36 N · m (25-27 lb · ft).
4. Install external high pressure fuel line. Refer to "2.19.3 Installation of External High Fuel Line" .
5. Install intake manifold. Refer to "6.3.3 Installation of Intake Manifold" .
   

   1.Retaining Nut‪	3.Cylinder Head‪
   2.Internal Fuel Line‪	‪

   Figure 4. Installation of Internal High Pressure Fuel Line