Series 638 – Section 2.5 Fuel Nozzle

Section 2.5
Fuel Nozzle

The Turbotronic 638 fuel nozzle performs the following functions: ‪

• Direct and atomize
• Manage and prepare the fuel spray
• Seal off the injection system from the combustion chamber

Section 2.5.1
Repair or Replacement of Fuel Nozzle

To determine if repair is possible or replacement is necessary, perform the following procedure. See Figure "Flowchart for Repair or Replacement of Fuel Nozzle" .‪

Figure 1. Flowchart for Repair or Replacement of Fuel Nozzle

Section 2.5.2
Removal of Fuel Nozzle

Remove the fuel nozzle(s) as follows:‪

1. Disconnect the fuel nozzle bleed line from the fuel nozzle. See Figure "High Pressure Fuel Line Removal" .
   

   1.Fuel Nozzle Bleed Line‪	3.Fuel Nozzle‪
   2.High Pressure Fuel Line‪	‪

   Figure 2. High Pressure Fuel Line Removal

2. Remove the high pressure injector line.
3. Remove fuel nozzle.
4. Disconnect the high pressure fuel lines. See Figure "High Pressure Fuel Line Removal" .
5. Disconnect the number one fuel nozzle sensor connector. See Figure "Number One Fuel Nozzle Sensor Connector Removal" .
   

   1.Fuel Nozzle (Number One)‪	3.Sensor Connector‪
   2.Fuel Nozzle Sensor‪	4.Copper Washer‪

   Figure 3. Number One Fuel Nozzle Sensor Connector Removal

   NOTICE:
   Using special tool J 42512, ensure that the special tool is firmly seated on the fuel nozzle to avoid bleed line-connector damage.‪

6. Remove the fuel nozzle(s) using special tool J 42512.

Section 2.5.2.1
Inspection of Fuel Nozzle

Inspect the fuel nozzle(s) as follows:‪

1. Visually check the fuel nozzle for a broken return line connector.
   1. If the fuel nozzle has a broken return line connector, replace the fuel nozzle. Refer to "2.5.3 Installation Fuel Nozzle" .
   2. If the fuel nozzle is not broken, proceed with step 2 of inspection.
2. Visually check number one fuel nozzle sensor connector for broken, bent, or corroded pins.
   1. If number one fuel nozzle sensor connector has broken, bent, or corroded pins, replace the fuel nozzle. Refer to "2.5.3 Installation Fuel Nozzle" .
   2. If number one fuel nozzle sensor connector has no broken, bent, or corroded pins, reuse the fuel nozzle. Refer to "2.5.3 Installation Fuel Nozzle" .
3. Visually check copper sealing washer for damage.

   Note: The copper sealing washer is not replaceable. If damaged, replace the fuel nozzle.

   1. If the copper sealing washer is damaged, replace the fuel nozzle. Refer to "2.5.3 Installation Fuel Nozzle" .
   2. If the copper sealing washer is not damaged, reuse the fuel nozzle. Refer to "2.5.3 Installation Fuel Nozzle" .

Section 2.5.3
Installation Fuel Nozzle

Install the fuel nozzle(s) as follows:‪

1. Install the fuel nozzle(s) using special tool J 42512. Torque to 68–72 N·m (50–53 lb·ft).

   NOTICE:
   Ensure that special tool J 42512 is firmly seated on the fuel nozzle to avoid bleed line-connector damage.‪

2. Connect number one fuel nozzle sensor connector. See Figure "Number One Fuel Nozzle Sensor Connector Removal" .
3. Connect the high pressure fuel lines. See Figure "High Pressure Fuel Line Removal" .
4. Connect the fuel nozzle return lines. See Figure "High Pressure Fuel Line Removal" .
5. Run engine to verify repair.