Komatsu Galeo PC138US-8 Shop Manual page 363

30 Testing and adjusting
4) Set the working mode in the power mode
(P) and set the travel speed in the High
position.
5) Run the engine at high idle, set all the
levers and pedals for work equipment con-
trol, swing control, and travel in neutral,
and test the oil pressure at each speed.
Then, operate the travel lever to run the
track shoe idle and test the oil pressure.
k
While checking the safety around
the machine extremely, run the
track shoe pushed up idle.
a Do not operate the travel lever to the
stroke end (but stop it halfway).
a Testing condition and method of judg-
ment: If the pressures are in the fol-
lowing ratio, the LS valve is normal.
Tested oil
pressure
Pump discharge
pressure
LS valve output
pressure
6) After finishing test, remove the testing
tools and return the removed parts.
2. Testing LS differential pressure
a Test the pump discharge pressure and LS
pressure (actuator load pressure) simulta-
neously and calculate the difference
between them.
1) Remove connector V5 (Port A4) of the
solenoid valve.
Purpose: Remove the connector to set the
merge-divider valve in the constant merge
state and stabilize the LS differential pres-
sure.
PC138US, USLC-8
Operation of lever and ratio
of oil pressures
All control Travel lever
levers and moved half-
pedals in neu- way (Track
tral shoe run idle)
1
Almost same
Approx. 0.6
(Approx. 3/5)
2) Open the side cover of the pump room
and remove oil pressure pickup plugs (1)
and (2).
(1): Pump discharge pressure pickup
q
plug
(2): LS pressure pickup plug
q
3) Install nipples M3 and connect it to differ-
ential pressure gauge M2 or the oil pres-
sure gauge [1] of hydraulic tester M1.
a When using differential pressure gauge
M2:
Connect the pump discharge pres-
sure to the high pressure side (back
side) and connect the LS pressure to
the low pressure side (lower side).
Since the differential pressure gauge
needs a 12V power source, connect it
to a battery.
a When using oil pressure gauge (in M1):
Use the oil pressure gauge of 58.8
MPa {600 kg/cm
0.98 MPa {10 kg/cm
ferential pressure is about 3.9 MPa
2
{40 kg/cm } at maximum, test it by
installing the same gauge to the
pickup plugs alternately.
The figure shows the pump discharge
q
pressure side.
SEN02458-01
2
} having the unit of
2
}. Since the dif-
35