Series 50 – Section 2.4 Fuel Injector Tube and O-Ring

Section 2.4
Fuel Injector Tube and O-Ring

The bore in the cylinder head for the EUI is directly through the cylinder head water jacket. To prevent coolant from contacting the injector and still maintain maximum cooling of the injector, a copper tube is pressed into the injector bore. The tube has a ring seal at the top and is flared at the bottom, on the lower side of the cylinder head, to create water and gas tight joints at the top and bottom. ‪

Note: It is recommended that the injector tube be replaced with new parts at the time of engine overhaul.

Section 2.4.1
Repair or Replacement of Fuel Injector Tube

To determine if repair or replacement of the fuel injector tube is necessary. See Figure "Flowchart for Repair or Replacement of Fuel Injector Tube" .‪

Figure 1. Flowchart for Repair or Replacement of Fuel Injector Tube

Section 2.4.2
Removal of the Injector Tube and O-Ring

When removing an injector tube, use injector tube installation, removal and refinishing tool set, J 33880 . ‪

1. Remove, disassemble and clean the cylinder head. Refer to "1.2.2 Removal and Cleaning of Cylinder Head" .
2. Place the injector tube installation/removal tool, J 33880-4 part of J 33880 , in the injector tube. Insert the pilot, J 5286-5 part of J 33880 , through the small opening of the injector tube and thread the pilot into the tapped hole in the end of the installation/removal tool. See Figure "Removal of Injector Tube" .
   

   Figure 2. Removal of Injector Tube

3. Tap on the end of the pilot using a brass hammer or fiber mallet. Carefully drive and lift the injector tube, installation/removal tool and pilot from the cylinder head. If the injector tube O-ring is not removed with the injector tube, remove the O-ring from the cylinder head casting at the upper end of the injector tube bore.

Section 2.4.3
Cleaning of Injector Tube

Thoroughly clean the injector tube hole in the cylinder head to remove any dirt, burrs, or foreign material that may prevent the new tube from seating at the lower end or sealing at the upper end. Excess material in the form of a small copper ring may be left at the lower end of the injector tube counterbore after the injector tube has been removed. This copper ring will have to be removed using a suitable sharp pointed tool.‪

Section 2.4.4
Installation of Auxiliary Injector Seal

Perform the following for installation of auxiliary injector seal.‪

NOTICE:

If a cylinder head has a damaged injector hole tube seal, coolant may seep past the seal after injector removal Drain down the injector tube hole, and fill the combustion chamber. If this condition goes undiscovered and the coolant is not removed from the cylinder before the injector is replaced, the engine may be damaged at startup. Always check cylinders for possible coolant seepage before replacing injectors and use care to prevent coolant or fuel from contaminating the engine lubricating oil.‪

NOTICE:
Do not use a metal dowel to install the auxiliary injector seal, as this may damage the seal.‪

1. Place the auxiliary seal in the injector hole.
2. Seat it against the top of the injector tube with a 1-5/8 in. diameter wood or plastic dowel. See Figure "Auxiliary Injector Seal Location" .

Figure 3. Auxiliary Injector Seal Location

Section 2.4.5
Installation of Injector Tube and O-Ring

Perform the following steps for injector tube installation:‪

NOTICE:
DO NOT lubricate the outside of the injector tube or inside the cylinder head injector tube bore to facilitate installation of the tube. Lubricant may cause the tube to turn during reaming or flaring operations possibly damaging the injector tube or reamers.‪

1. Lubricate the blended fluorocarbon injector tube sealing O-ring with liquid hand soap.

   Note: This ring was formerly made of fluoroelastomer and had a blue coating for identification. It is now made of a special blended fluorocarbon material with an orange Teflon coating for identification. Former and current-design seal rings are completely interchangeable, and only the current orange-coated seal ring will be serviced.

2. Place the O-ring over the injector tube, sliding it up to the lip.
3. Install the injector tube on the injector tube installation/removal tool, J 33880-4 part of J 33880 . See Figure "Installing Injector Tube" .
   

   Figure 4. Installing Injector Tube

4. Install the injector tube installation/removal tool with tube in place, into the injector bore. Be sure the tip of the injector tube goes through the small hole in the fire deck. Tap lightly on the end of the tool, if necessary, to seat the tube.
5. Install the EUI hold-down clamp and bolt it in place over the installation/removal tool. See Figure "Installing Injector Hold-down Clamp" .
   

   Figure 5. Installing Injector Hold-down Clamp

6. Torque the EUI hold-down clamp bolt 58-66 N·m (43-49 lb·ft). This will seat the injector tube at the desired depth.

After an injector tube has been installed in a cylinder head, it must be finished. For flaring injector tube, use injector tube installation, removal and refinishing tool set, J 33880 . See Figure "Injector Tube Installation Tool Set" .‪

Figure 6. Injector Tube Installation Tool Set

Perform the following steps for a flaring injector tube:‪

1. Insert the injector tube flaring tool, J 5286-6 part of J 33880 through the small hole in the bottom of the tube, rotating to engage the threads in the installation/removal tool.
2. Using a torque wrench and 12-point, 29/32 in. socket, screw the flaring tool into the tube installation/removal tool until it begins to flare the tube. See Figure "Flaring Injector Tube Tip" .
   

   Figure 7. Flaring Injector Tube Tip

3. Continue to rotate the flaring tool and apply pressure to the flare end of the tube firmly against the cylinder head casting tube opening. Do not exceed 41 N·m (30 lb·ft) torque. See Figure "Properly Flared Injector Tube Tip" .
   

   Figure 8. Properly Flared Injector Tube Tip

4. Remove the flaring and installation tools.

The tapered lower end of the injector tube must provide a smooth and true seat for the lower end of the injector nut to effectively seal the cylinder pressures and properly position the injector tip into the combustion chamber. To ream the injector tube, complete the following steps:‪

1. Install the seat reamer pilot tool, J 33880-3 part of J 33880 , into the injector bore until it contacts the cylinder head.

   NOTICE:
   Turn the reamer in a clockwise direction only (both when inserting and withdrawing the reamer) because movement in the opposite direction will dull the cutting edges of the flutes.‪

2. Install the tip reamer pilot tool, J 33880-10 part of J 33880 , into the seat reamer pilot until it bottoms.
3. Place a few drops of cutting oil on the cutting edges of the tube tip reamer tool, J 33880-5 part of J 33880 , and install it in the pilot. See Figure "Reaming Injector Tube Tip" .
   

   Figure 9. Reaming Injector Tube Tip

4. Using a speed handle with 7/16 in. socket attached, turn the tip reamer in a clockwise direction using light pressure until it goes completely through the end of the injector tube.

   EYE INJURY ‪
   To avoid injury from flying debris when using compressed air, wear adequate eye protection (face shield or safety goggles) and do not exceed 276 kPa (40 psi) air pressure.‪

5. Remove the reamer and pilot. Blow out the injector tube and tip with compressed air to remove all metal shavings.
6. Install the stop block tool, J 33880-20 part of J 33880 , to the firedeck of the cylinder head using two existing head bolts. Tighten the head bolts, but do not torque. Position the cut out portion of the stop block beneath the injector tube. See Figure "Stop Block Installed on Cylinder Head" .
   

   Figure 10. Stop Block Installed on Cylinder Head

7. Install the seat reamer pilot tool, J 33880-3 part of J 33880 , into the injector tube bore until it contacts the cylinder head.

   NOTICE:
   If the seat reamer is dropped into the pilot, or is allowed to strike the injector tube, this may cause chatter marks in the seat. Use extreme care when inserting the seat reamer to prevent damaging the tube.‪

8. Place a few drops of cutting oil on the edges of the seat reamer tool, J 33880-1 part of J 33880 , and gently place it in the pilot. See Figure "Reaming Injector Tube Seat" .
   

   Figure 11. Reaming Injector Tube Seat

   NOTICE:
   Turn the reamer in a clockwise direction only, because movement in the opposite direction will dull the cutting edges of the flutes.‪

9. Using a speed handle with 15/16 in. socket attached, turn the seat reamer in a clockwise direction with light pressure. Continue until the reamer bottoms against the stop block.
10. Inspect the tube seating surface to ensure that there are no irregularities or chatter marks in the seating surface. If irregularities or chatter marks are found, remove and replace the injector tube. See Figure "Injector Tube Seat Irregularities" .
    

    Figure 12. Injector Tube Seat Irregularities

    EYE INJURY ‪
    To avoid injury from flying debris when using compressed air, wear adequate eye protection (face shield or safety goggles) and do not exceed 276 kPa (40 psi) air pressure.‪

11. Remove the reamer and pilot. Clean out the injector tube with compressed air.
12. Remove the two head bolts and stop block from the cylinder head.
13. Spot-face the injector tube as follows:
    1. With the cylinder head firedeck in a workable position, insert the tube tip refinisher tool, J 5286-8 part of J 33880 , into the injector tube. See Figure "Refinishing Injector Tube Tip" .
    

    Figure 13. Refinishing Injector Tube Tip

    2. Using a 12-point socket and speed handle, turn the refinisher to remove excess stock so that the lower end of the injector tube is from flush to 0.76 mm (0.003 in.) below the firedeck surface of the cylinder head.
    3. Remove the chips from the injector tube.

Section 2.4.5.1
Check Injector Tip Protrusion

To check the injector tip protrusion:‪

1. Insert the seat reamer pilot tool, J 33880-3 part of J 33880 , into injector tube bore of cylinder head.
2. Insert protrusion gage tool, J 33880-7 part of J 33880 , into pilot. See Figure "Checking Injector Tip Protrusion" .
   

   Figure 14. Checking Injector Tip Protrusion

3. Check injector tip protrusion using sled gage tool, J 22273-01 . Hold protrusion gage against pilot while measuring tip protrusion. This measurement should be flush to 0.2032 mm (0.008 in.) below the firedeck surface.