MBE 900 – Section 2.3 Nozzle Holder

Section 2.3
Nozzle Holder

Unit pumps, one for each cylinder, boost minimum fuel pressure to 24,500 kPa (3553 psi) for purposes of injection. The fuel passes through a high-pressure line, a transfer tube inserted into the wall of the cylinder head, and finally into the nozzle holder, where it is injected into a specially-designed swirl cup in the head of the piston.‪

Section 2.3.1
Nozzle Holder Removal

Remove the nozzle holder as follows:‪

1. Remove the cylinder head cover. Refer to "1.1.1 Cylinder Head Cover Removal" .
2. Remove the injection line. See Figure "Fuel Injection System (exploded view)" .
   

   1. Nozzle Holder‪	6. Transfer Tube O-ring‪
   2. Heat Isolator‪	7. Transfer Tube‪
   3. Retaining Bolt‪	8. Thrust Bolt‪
   4. Tensioning Arm‪	9. Injection Line‪
   5. Nozzle O-ring‪

   Figure 1. Fuel Injection System (exploded view)

3. Remove the transfer tube. Discard the old O-ring.
4. Remove the tensioning arm.
5. Attach the adapter J 46384 and impact extractor J 46375 . Thread the narrow end of the adaptor onto the internal threading in the head of the nozzle holder. Thread the impact extractor onto the wide end of the adaptor. See Figure "Fuel Injection System (exploded view)" .

   Note: Do not attempt to take apart the nozzle holder. If there is a problem, replace the nozzle holder.

6. Using the impact extractor, pull out the nozzle holder.
7. Remove the impact extractor and adaptor from the nozzle holder.
8. Take the heat isolator off the nozzle holder. See Figure "Heat Isolator Removal" . Discard the old O-ring.
   

   1. Nozzle Holder‪	4. Transfer Tube‪
   2. Heat Isolator‪	5. Thrust Bolt‪
   3. O-ring‪

   Figure 2. Heat Isolator Removal

Section 2.3.2
Nozzle Holder Installation

Install the nozzle holder as follows:‪

1. Lubricate the new O-ring with a light coat of grease and install it on the nozzle holder.
2. Using the heat isolator installer J-46393 , press the new heat isolator onto the nozzle.
   1. Position the new heat isolator over the nozzle.
   2. Place the receptacle from the heat isolator installer over the head of the nozzle holder and the pressure-fit cap over the heat isolator. See Figure "Heat Isolator Installer Components (J 46393)" and see Figure "Pressure-Fitting the Heat Isolator onto the Nozzle" .
      

      Figure 3. Heat Isolator Installer Components (J 46393)

   3. Place this entire assembly in a vise and close the vise enough to pressure-fit the heat isolator around the nozzle. See Figure "Pressure-Fitting the Heat Isolator onto the Nozzle" .
      

      1. Nozzle‪	3. Nozzle Holder‪
      2. Heat Isolator‪	4. Vise‪

      Figure 4. Pressure-Fitting the Heat Isolator onto the Nozzle

   4. Open the vise and remove the two parts of the heat isolator installer from the nozzle holder. Check that the heat isolator is firmly pressed onto the nozzle.

   Note: Take care that the nozzle holder is installed correctly and is aligned properly with respect to the transfer tube.

3. Install the nozzle holder. See Figure "Nozzle Holder Installation" .
   

   1. Nozzle Holder‪	4. Retaining Bolt‪
   2. Tensioning Arm‪	5. Interference-Fit Ball‪
   3. End Cover (constant throttle valve)‪

   Figure 5. Nozzle Holder Installation

   1. Use the tensioning arm to turn the nozzle holder until the interference-fit ball in the tensioning arm lines up with the locating element in the end cover of the constant throttle valve.
   2. Tighten the retaining bolt on the tensioning arm 30 N·m (22 lb·ft) for the recessed hex head bolt and 35 N·m (26 lb·ft) for the 12-point bolt with the spherical collar.
4. Lubricate the new O-ring with a light coat of grease and install it on the transfer tube.

   Note: Take care that the interference-fit ball on the transfer tube fits into the slot in the cylinder head.

5. Install the transfer tube. See Figure "Transfer Tube Installation" .
   

   1. Thrust Bolt‪	3. Interference-Fit Ball‪
   2. Transfer Tube‪	4. Slot in Cylinder Head‪

   Figure 6. Transfer Tube Installation

   1. Align the interference-fit ball on the transfer tube with the slot in the cylinder head, and push the transfer tube into the cylinder head.
   2. Tighten the thrust bolt 40 N·m (30 lb·ft).
6. Install the injection fuel line. Refer to "2.2.2 Fuel Injection Line Installation" .
7. Install the cylinder head cover. Refer to "1.1.2 Cylinder Head Cover Installation" .