ONL773LW4 5/21
19
Servicing
SP11. INJECTOR SERVICE
1. Injectors should be checked every 1000 hours.
Check should be made by a Northern Lights dealer
or local injection repair station.
CAUTION: Escaping diesel fuel under pressure
can have sufficient force to penetrate the skin
causing serious personal injury. If injured by
escaping diesel 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 (
Figure 8
).
c. Remove delivery lines by disconnecting from
injectors and injection pump (
Figure 9
). Remove
all lines as an assembly; do not remove the
spacers. Cover the ends of the lines, the injector
inlets and injection pump outlets to keep dirt out.
d. Remove the return line retaining bolts (
Figure 10
).
Remove the return line (
Figure 11
).
e. Unscrew and remove the injectors (
Figure 12
).
NOTE: Do not use pry bars to remove injectors
from cylinder head.
f. After removing the injectors, discard the copper
sealing washers from the injector hole in the head
(
Figure 13
). Cover holes to prevent dirt and debris
from entering the cylinders.
3. Injector installation:
a. Install a new copper sealing washer in each
injector hole (
Figure 13
).
b. Screw in injector and tighten to 43 or 50 ft/lbs
(6 to 7 kgm) (
Figure 14
).
NOTE:
Overtightening can damage injector.
c. Install return line using new copper sealing above
and below each connection. Tighten return line
retaining bolts to 22 - 30 ft/lbs.
d. Install delivery lines. Leave loose at injectors for
bleeding.
e. Pump hand level on fuel pump to fill lines.
Tighten lines at injectors. Start engine and check
for leaks using a piece of paper or cardboard.
DO NOT use hand to check for leaks.
SP12. INJECTION PUMP
1. Since operating conditions may vary considerably, it
is difficult to give a definite interval for checking the
injection pump. But as a rule, pump settings,
maximum speed, idle speed and exhaust smoke
should be checked after every 2500 hours of
operation. Service of the fuel injection pump should
only be done if checks indicate pump malfunction.
2. Black smoke can be an indication of pump
malfunction. Before servicing the pump, check other
possible causes:
a. Check cleanliness of air filter.
b. Check valve clearances.
c. Clean and check injectors.
3. Any repair which involves disassembly of the
injection pump must be carried out by specially
trained mechanics with the proper tools and test
equipment.
NOTE: All warranties on the engine become null
and void if the injection pump seals are broken by
unauthorized persons.
COOLING SYSTEM - GENERAL
CAUTION: The cooling water in the engine
reaches extremely high temperatures. You must
use extreme caution when working on hot
engines to avoid burns. Allow the engine to cool
before working on the cooling system. Open the
filler cap carefully, using protective clothing
when the engine is warm.
WATER QUALITY
1. Distilled, deionized, soft water is preferred for use in
cooling systems. Bottled distilled water from a food
store or water supplier is recommended. Tap water
often has a high mineral content. Tap water should
NEVER
be put in a cooling system unless first tested
by a water quality laboratory. Do not use water
made by the reverse osmosis method unless it has
been PH neutralized.
Updated 11-8-13
