Injectors; Checking And Setting The Injectors; Disassembly And Re-Assembly Of Injectors - Kohler KD 425-2 Workshop Manual

46
47
48
49
KD 425-2 Workshop Manual_cod. ED0053029360_1° ed_ rev. 00

Injectors

Details of fig.46:
1.Injector casing - 2.Adjusting shim - 3.Spring - 4.Rod - 5.Distance
ring with locating pin - 6.Nozzle - 7.Ring nut

Checking and setting the injectors

1. Clean the nozzle holes with 0.25mm gauge steel wire (fig.47).
2. Place the injector on the test bench (p.n. 00365R0430, fig.48)
bypass the pressure gauge and operate the lever rapidly. The
nozzle should chatter audibly and spray correctly.
3. Connect the pressure gauge while pressing the lever slowly and
steadily until injection occurs.
The opening pressure registered on the gauge should be 230 Kg/
cm² (200 Kg/cm² on silenced versions).
Change the adjusting shims (nr. 2, fig. 46) in order to achieve
correct adjustment.
4. Testing fortightness: Operate test bench hand lever until the
pressure gauge reads 20 Kg/cm² below the opening pressure
of the needle valve. The nozzle can be considered well sealed if
there no Diesel fuel accumulates at the nozzle tip after 10 secon-
ds.

Disassembly and re-assembly of injectors

Unscrew the ring nut on the injector nozzle using a ring wrench and a
special tool as illustrated in figure 49 serving to release the pressure
exerted by the spring on the ring nut.
1. Visual check: make sure that the seat of the needle shows no
signs of hammering or excess roughness, that the needle is not
worn or damaged, and that the holes are free of carbon deposits.
2. Smoothness test: the needle, previously immersed in diesel and
inserted into the nozzle casing, must be pulled out to a third of
the length of the guide while holding the nozzle in a vertical po-
sition. When the needle is released it should return freely to its
seat by the effect of its own weight.
Reassemble the injector following the assembly order shown in figure
46; during reassembly make sure that the locating elements on di-
stance ring 5 (fig.46) are correctly inserted to the corresponding ho-
les. Torque the nozzle securing ring nut to:
kgm 3,5 (Nm 34,3)
INJECTION EQUIPMENT
XI
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