TM 5-3895-359-14&P
FUEL INJECTOR TUBE
The bore in the cylinder head for the fuel injector is
Remove Injector Tube
directly through the cylinder head water jacket as shown
in Fig. 1. To prevent coolant from contacting the
When removal of an injector tube is required, use;
injector and still maintain maximum cooling of the
injector tube service tool set J 22525 as follows:
injector, a tube is pressed into the injector bore. This
tube is sealed at the top with a neoprene ring and upset
1. Remove, disassemble and clean the cylinder head
into a flare on the lower side of the cylinder head to
as outlined on Page 10-2-20.
create water-tight and gas-tight joints at the top and
bottom.
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. I ).
Effective with engine serial number 4A-222102 a new
Fluoroelastomer (Viton) seal ring is being used.
3. Tap on the end of the pilot to loosen the injector
tube. Then lift the injector tube, installer and pilot from
NOTE: Do not use methoxy propanol based antifreeze
the cylinder head.
in the cooling system of any Detroit Diesel engine built
after the above engine serial numbers, or engines where
Install Injector Tube
the new (Viton) seal ring has been installed.
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: I.
Repair Leaking Injector Tube
Place a new injector tube seal ring in the counterbore in
the cylinder head.
To enable the repair of a leaking fuel injector hole tube
at the seal ring, without removing the cylinder head from
2. Place the installer J 5286-4 in the injector tube.
the cylinder block, a new injector hole tube swaging tool
Then insert the pilot J 5286-5 through the small opening
J 28611 is now available.
of the injector tube and thread it into the tapped end of
the installer (Fig. 2).
Before removing the fuel injector, pressurize the cooling
system at the radiator to verify the injector tube seal
3. Slip the injector tube into the injector bore and drive
ring leak. Then with the fuel injector removed, insert
it in place as shown in Fig. 2. Sealing is accomplished
the swaging tool into the fuel injector hole tube. The
between the head counterbore (inside diameter) and
tool is tapered and flanged to prevent damage to the
outside diameter of the injector tube. The tube flange is
cylinder head or injector tube. Hit the top of the tool
merely used to retain the seal ring.
moderately with a one pound hammer two or three
blows seating the tool. This will cause the top edge of
the injector hole tube to expand, thus increasing the
crush on the injector tube seal ring and seal the leak.
Install the fuel injector and again pressurize the cooling
system to verify the leak has been stopped.
This tool was designed mainly for use on engines built
between July, 1973 and August, 1977 with fuel injector
hole tube seal rings that may be pressure sensitive and,
if so, could take a heat set. The result being a coolant
leak at the seal ring. The use of the swaging tool, as
stated above, will restore tension to the seal ring.
Fig. 1 - Removing Injector Tube
10-3-25
