Injector Service - Northern Lights OM944W3 Operator's Manual

SP-11. INJECTOR SERVICE
1. Injectors should be checked every 500 hours. This
check should be made by a Northern Lights dealer
or local injection repair station. Expected service life
of the engine's injectors is 5,000 hours.
CAUTION: Escaping diesel fuel under pressure
can have sufficient force to penetrate the skin
causing serious personal injury. If injured by
escaping fuel, see a doctor at once.
2. Injector removal:
a. Clean loose dirt from around the injectors and
the fuel lines.
b. Relieve high pressure in the fuel lines by
loosening the delivery line flare nuts at each
injector.
c. Remove delivery lines by disconnecting them
from the injectors and injection pump.
Remove all lines as an assembly; do not remove
the spacers. Cover the ends of the lines, the injector
inlets, and the injection pump outlets to keep dirt
out.
d. Remove the return line retaining bolts, washers,
and return line.
e. Loosen the injector retaining nuts at the same
time a little at a time. Remove the injector.
f. Remove the injector seat. Cover the holes to
prevent debris from entering the cylinders.
Note: Do not use pry bars to remove injectors
from the cylinder head.
Updated 7-1-22
Servicing
3. Injector repair and cleaning:
a. Take injectors to your Northern Lights dealer
or local injection repair station for testing and
service.
4. Injector installation:
a. Install new injector seal washer seat and
injector. Evenly tighten the injector retaining
nuts to 39.1 to 47.7 ft/lbs (53.0 to 64.7 N•m), or
5.4 to 6.6 kgf•m. Do not overtighten.
b. Reinstall the return line using new sealing
washers. Tighten bolts to 13.0 to 15.9 ft/lbs
(17.7 to 21.6 N•m), or 1.8 to 2.2 kgf•m.
NOTE: Overtightening can damage injectors.
c. Reinstall injection lines. Tighten
flare nuts at injection pump to 19.5 to 23.9
ft/lbs (26.5 to 32.4 N•m), or 2.7 to 3.3 kgf•m.
Leave the lines loose at injectors for bleeding.
d. Bleed the injection lines. Crank the
engine to fill the lines. Tighten flare nuts at
injectors to 15.2 to 18.1 ft/lbs (20.6 to 24.5 N•m),
2.1 to 2.5 kgf•m.
e. Start the engine and check for leaks using a
piece of paper or cardboard. Do not use your
hand to check for leaks.
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