Komatsu ecot3 PC300LC-8 Shop Manual page 381

30 Testing and adjusting
3) Start the engine and keep it running until the
hydraulic oil temperature rises to the oper-
ating range.
4) Measure the pump discharge pressure and
PC valve output pressure (pressure at servo
piston inlet) at the same time after setting
following conditions with the engine running
at high idle.
q Working mode: P-mode
q Swing lock switch: ON
(Turning 2-stage relief ON induces
high-pressure relief)
q Work equipment, swing and travel: Arm
IN relief
a Judgement method: When the ratio be-
tween the pump discharge pressure and
PC valve output pressure (servo piston
input pressure) reaches the following val-
ues, both pressures are judged normal.
Measured oil pres-
sure
Pump discharge
pressure
PC Valve output
pressure
a If there is any abnormality with PC valve
or servo piston, the PC valve output pres-
sure (servo piston input pressure) be-
comes identical with the pump discharge
pressure or comes to neighborhood of 0
pressure.
PC300, 350-8
2. Measurement of PC-EPC valve output pres-
Ratio between oil
pressures
1
Approx. 3/5
sure
1) Remove oil pressure measurement plug (5).
a The plug is installed in the front side of the
machine.
2) Fit nipple L2 and connect it to oil pressure
gauge [1] of hydraulic tester L1.
a Use the oil pressure gauge with capacity
6.0 MPa {60 kg/cm
3) Start the engine and keep it running until the
hydraulic oil temperature rises to the oper-
ating range.
SEN02625-06
2
}.
41