DETROIT DIESEL 53
FUEL INJECTOR TUBE
The bore in the cylinder head for the fuel injector is directly through the cylinder head water jacket as shown in
Fig. 1. To prevent coolant from contacting the injector and still maintain maximum cooling of the injector, a
tube is pressed into the injector bore. This tube is sealed at the top with a neoprene ring and upset into a flare
on the lower side of the cylinder head to create water-tight and gas-tight joints at the top and bottom.
Remove Injector Tube
When removal of an injector tube is required, use injector tube service tool set J 22525 as follows:
1. Remove, disassemble and clean the cylinder head as outlined in Section 1.2.
2. Place the injector tube installer J 5286-4 in the injector tube. Insert the pilot J 5286-5 through the small
opening of the injector tube and thread the pilot into the tapped hole in the end of the installer ( Fig. 1).
3. Tap on the end of the pilot to loosen the injector tube. Then lift the injector tube, installer and pilot from
the cylinder head.
Install Injector Tube
Thoroughly clean the injector tube hole in the cylinder head to remove dirt, burrs or foreign material that may
prevent the tube from seating at the lower end or sealing at the upper end. Then install the tube as follows:
1. Place a new injector tube seal ring in the counterbore in the cylinder head.
2. Place the installer J 5286-4 in the. injector tube. Then insert the pilot J 5286-5 through the small opening
of the injector tube and thread it into the tapped end of the installer ( Fig. 2).
3. Slip the injector tube into the injector bore and drive it in place as shown in Fig. 2. Sealing is
accomplished between the head counterbore (inside diameter) and outside diameter of the injector tube. The
tube flange is merely used to retain the seal ring.
4. With the injector tube properly positioned in the cylinder head, upset (flare) the lower end of the injector
tube as follows:
a. Turn the cylinder head bottom side up, remove the pilot J 5286-5 and thread the upsetting die
Fig. 1. Removing Injector Tube
Fig. 2. Installing Injector Tube
Fig. 2 Installing Injector Tube
November, 1973 SEC. 2.1..4