Komatsu ecot3 PC300LC-8 Shop Manual page 378

SEN02625-06
3) Check the pressure again after the adjust-
ment, following the aforementioned steps for
measurement.
a Connect the pilot hose when measuring
the oil pressure.
3. Adjustment of boom LOWER relief pressure
(on the side where low pressure is set)
a When low-pressure relief pressure of the
boom LOWER is not normal or when adjust-
ment is made of the high pressure setting
side, adjust the low pressure side of the safe-
ty and suction valve for the boom LOWER in
the following procedure.
a The low-pressure relief pressure mode de-
notes the state in which the machine push-up
switch is turned off, disabling to apply the pi-
lot pressure to the switching port.
1) Disconnect the pilot hose.
2) Loosen locknut (10) and turn holder (11) to
adjust the relief pressure.
a Turning the holder clockwise increases
the pressure. Turning it counterclockwise
decreases the pressure.
a Pressure adjustable from a single turn of
the holder:
Approx. 21.8 MPa{Approx. 222 kg/cm
3
Locknut:
3) Check the pressure again after the adjust-
ment, following the aforementioned steps for
measurement.
a Connect the pilot hose when measuring
the oil pressure.
38
78 - 93 Nm {8.0 - 9.5 kgm}
4. Adjustment of swing relief pressure
a If the swing relief pressure is not normal, ad-
just the swing motor safety valve (12) in the
following manner.
1) Loosen locknut (13) and turn adjustment
screw (14) to adjust the relief pressure.
a Turning the holder clockwise increases
the pressure. Turning it counterclockwise
decreases the pressure.
a Quantity of adjustment per turn of adjust-
ing screw:
Approx. 4.70 MPa {Approx. 47.9
2
}
kg/cm
3
Locknut:
2) Check the pressure again after the adjust-
ment, following the aforementioned steps for
measurement.
30 Testing and adjusting
2
}
147 - 196 Nm {15 - 20 kgm}
PC300, 350-8