OM673L2 08/05
17
Servicing
SP11. INJEcTOR SERvIcE
1. Injectors should be checked every 1000 hours, or
more often as necessary. 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 13
).
c. Remove delivery lines by disconnecting from
injectors and injection pump (
Figure 14
). Remove
all lines as an assembly; do not remove the
clamp. Cover the ends of the lines, the injector
inlets and injection pump outlets to keep dirt out
(
Figure 15
).
d. Remove the return line retaining bolts (
Figure 16
).
Remove the return line (
Figure 17
).
e. Unscrew and remove the injectors (
Figure 18
).
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 19
). Cover holes to prevent dirt and debris
from entering the cylinders.
. Injector installation:
a. Install a new copper sealing washer in each
injector hole (
Figure 19
).
b. Screw in injector and tighten to or 50 ft/lbs
(6 to 7 kgm) (
Figure 20
).
NOTE:
Overtightening can damage injector.
c. Install return line using new copper sealing below
each connection. Tighten return line retaining
bolts to 22 - 0 ft/lbs.
d. Install delivery lines. Leave loose at injectors for
bleeding.
e. Crank the engine 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 200 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.
. 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
NOTE: Be sure to close the sea-cock before working
on the engine cooling system.
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.
SP13. chEcK ThE cOOLANT LEvEL
1. Check the coolant level each day before starting the
engine. Check the water level by removing the pres-
sure cap from the expansion tank or radiator.
In order to give the cooling water an opportunity to
expand, the level should be about 1 in. (2.5 cm) below
the filler cap sealing surface when the engine is cold.
2. The pressure valve in the filler cap releases when the
pressure is approximately 7 PSI (0.5 bar). Use a cap
pressure tester to check cap if you suspect it is faulty.
