DD 15 – Section 35.6 Fuel Injector Tube

Section 35.6
Fuel Injector Tube

The bore in the cylinder head is for the fuel injector tube. The injector tube prevents coolant from contaminating the injector and maintains maximum cooling of the injector. The injector tube is a stainless steel tube screwed into the cylinder head. There is an O-ring installed in the cylinder head to create a water and fuel tight seal.‪

Section 35.6.1
Removal of Fuel Injector Tube

Remove as follows:‪


Engine coolant must be drained prior to injector tube removal.‪

  1. Drain the engine coolant.
  2. Remove injector harness.
  3. Remove the injectors.
  4. Install tool J-47388–8 into injector tube and align tool with slots in tube and turn counter clockwise to remove.
  5. Remove injector tube; discard injector tube O-ring in cylinder head.
  6. Inspect the injector tube for cracks or defects. If defective replace injector tube.
  7. Clean injector tube threads with a fine wire brush, being careful not to abrade the cylinder head to injector tube sealing surface.
  8. Clean the injector tube interior sealing surface, a chemical solvent maybe used for cleaning interior sealing surface.

Section 35.6.2
Installation of Injector Tube

Install as follows:‪

  1. Clean the injector bore of debris.


    Take extra precautions when cleaning the injector bores to ensure that debris does not enter the fuel system. Do not use power tools to clean the injector bores, use J–47375 hand brush and a rag. Do not use compressed air to blowout debris in the bores.‪

    Note: Replace injector tube O-ring with a new O-ring when injector tube is removed or replaced.

  2. Install O-ring in cylinder head, a small amount of silicone based O-ring lubrication will aid in the installation.
  3. Coat the threads of the injector tube and tube sealing surface with a high temperature nickel based anti-seize lubricant.
  4. Install injector tube onto tool J–47388 and install into injector bore.
  5. Torque injector tube to 45 N·m + 5 N·m (33 ft·lb + 3 ft·lb).
  6. Release torque approximately 180°.
  7. Torque injector tube to 45 N·m + 5 N·m (33 ft·lb + 3 ft·lb). If cylinder head has been removed ensure the tip of the tube is flush with the fire deck.
  8. Install any components that were removed for this procedure.
  9. Fill and pressure test the cooling system; check for leaks.

DD15 Fuel System Technician's Guide - DDC-SVC-MAN-0037
Generated on 10-13-2008

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