Testing And Adjusting Pump Ls Control Circuit Oil Pressure - Komatsu ecot3 PC300LC-8 Shop Manual

30 Testing and adjusting
Testing and adjusting pump LS
control circuit oil pressure
a Pump LS control circuit oil pressure testing and
adjusting tools
Symbol Part No.
799-101-5002 Hydraulic tester
1
790-261-1204 Digital hydraulic tester
M 799-101-5220 Nipple (10 × 1.25 mm)
2
07002-11023
3 799-401-1340 Differential pressure gauge
Measurement
a Measurement of the oil pressure in the pump LS
control circuit shall be conducted after making
sure that oil pressure of the work equipment,
swing, and travel circuits as well as basic pres-
sure of the control circuit is normal.
k
Lower the work equipment to the ground
and, after stopping the engine, release resid-
ual pressure in the piping by operating the
control lever several times. Then loosen the
oil filler cap gradually to release pressure in-
side the tank.
1. Measurement of LS valve output pressure
(servo piston inlet pressure)
a Measure the LS valve output pressure (servo
piston inlet pressure) and pump discharge
pressure simultaneously tocompare them.
1) Remove oil pressure measurement plugs (1),
(2), (3) and (4).
q (1): For the front pump discharge pres-
sure (situated in the rear side of the ma-
chine)
q (2): For the rear pump discharge pressure
(situated in the front side of the machine)
(3): For the front pump LS valve output
q
pressure
q (4): For the rear pump LS valve output
pressure
PC300, 350-8
Part name
O-ring
2) Fit nipple M2 and connect it to oil pressure
gauge [1] of hydraulic tester L1.
a Use the oil pressure gauge with capacity
60 MPa {600 kg/cm
SEN02625-06
2
}.
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