Komatsu Utility PC12R-8 MISTRAL, Shop Manual

Page: 177 / 324

CONTROL AND REGULATION OF THE LS DIFFERENTIAL
PRESSURE AND ADJUSTMENT OF THE LS VALVE
20-43
TESTING AND ADJUSTMENTS
CONTROL AND REGULATION OF THE LS DIFFERENTIAL
PRESSURE AND ADJUSTMENT OF THE LS VALVE
Test
1. Test method with differential pressure gauge E3
1 - Remove the plugs (1) and (2) and mount two pres-
sure adapters.
2 - Connect the differential pressure gauge E4 .
H Connect the high-pressure side to the adapter
(3) and the low-pressure side to the adapter
(4).
3 - Start the engine and use the working equipment
to raise one track-shoe.
4 - Bring the engine up to high idling and check the
LS differential pressure according to the test con-
ditions in Table 1.
Table 1
Position of
the travel
lever
LS differential pressu-
re in kg/cm
2
NOTES
Neutral 20 10
The LS differential pressure
is equal to the pressure gi-
ven by the unloading valve
Half the
stroke (Swing
without load)
2. Test method with pressure gauges E2 or E3
H The maximum differential pressure is 20 kg/cm
2
(roughly 20 bar). For a precise check use the sa-
me pressure gauge together with a decimal scale.
1 - Remove the plugs (1) and (2) and mount two
pressure adapters.
2 - Connect pressure gauge E2 or E3 to the pressu-
re adapter (3).
3 - Start the engine and use the working equipment
to raise one track-shoe.
4 - Bring the engine up to high idling and measure
the delivery pressure of pump ( P
P
) in the condi-
tions shown in Table 1. Make a note of the values
read.
H Check the instrument by reading it from the
front and making sure that the reading is cor-
rect.
5 - Disconnect the pressure gauge E2 or E3 from the
pump delivery and connect it to the pressure
adapter (4).
6 - Measure the LS pressure in the same conditions
indicated at point 4. Make a note of the value read.
7 - Subtract the LS pressure from the delivery pres-
sure of the pump ( P
P
) in order to obtain the diffe-
rential pressure value D P
LS
( P
P
± LS = D P
LS
)
H D P
LS
normal=20 10 kg/cm
2
(19.6 9.8 bar)
PC12R-8 PC15R-8
RKPA0330
2
1
RKPA2040
4
3
E
4
RKPA0321
2
3
E
3
RKPA0340
4
1
E
3