- 34 -
44
42
43
45
5
Warning
•
The difference between the deliveries of the two pumps when
locked must not exceed 0.5 cc.
Also check:
1
. That the distance between the injection cams in the rest
position (bottom dead centre) and the pump supporting face
is between
52.8
÷
54.4 mm
as shown on the data plate;
2
. That the stroke of the piston with injection cams in the rest
position (bottom dead centre), to the start of delivery is
between
2
÷
2.1 mm.
Assembly of injection pumps
If it proves necessary to disassemble the injection pumps they
must be reassembled following the instructions listed below:
1
. Insert barrel into pump casing with the fuel inlet hole aligned
with the feeding connection (fig.42). This is the only possible
position because of the stud on the pump body. Make sure
that the seating face between the barrel and the pump are
free of dirt.
2
. Insert delivery valve, copper gasket, spring, washer, filler,
O-ring, and temporarily tighten the delivery connection.
3
. Insert plunger, with helical profile (
A
, fig.43) on the opposite
side of the sleeve pin (
B
, fig.43), into the internal groove of
the control sleeve (make sure the helical profile is turned
towards the fuel inlet and eccentric pin (
C
, fig.43).
4
. Complete pump assembly with plunger (
a
, fig.44), control
sleeve (
b
), upper washer (
c
), retaining ring (
d
), spring (
f
)
and secure all with the spring holder washer (
g
)
5
. Tighten delivery valve holder (
h
, fig.44) to 4.5 ÷ 5 kgm
torque.
6
. Check, by compressing the spring through its various work
positions, that the control sleeve (
b
, fig.44) turns freely and
does not stick or encounter resistance throughout its full
stroke; any irregular movement will give rise to hunting of
engine speeds.
7
. Secure the control sleeve using the pin (
n
, fig.44) screwed
into pump housing.
Warning
•
Always check the injection pump calibration after the delivery
connection (
h
, fig.44) has been dismantled.
Testing air tightness
Feed pressurized air at 6 Kg/cm² into the fuel sullpy union and
completely immerse the pump in oil or diesel fuel for about 20 ÷
30 seconds (fig.45); check that no air bubbles are released.
N.B.:
Tightness can be checked by compressing the springs to
52.8 ÷ 54.4 mm, which corresponds to the bottom dead
centre working position of the pump.
Injection equipment
KD425-2 Workshop Manual_cod. ED0053031750_
1° ed
_ rev.
00
Summary of Contents for KD425-2
Page 1: ...KD 425 2 WORKSHOP MANUAL...
Page 6: ...6 KD425 2 Workshop Manual_cod ED0053031750_1 ed_ rev 00...
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Page 54: ...54 KD425 2 Workshop Manual_cod ED0053031750_1 ed_ rev 00...
Page 55: ...55 KD425 2 Workshop Manual_cod ED0053031750_1 ed_ rev 00...
