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

SEN02625-06
Testing and adjusting pump PC
control circuit oil pressure
a Pump PC control circuit oil pressure testing and
adjusting tools
Symbol Part No.
799-101-5002 Hydraulic tester
1
790-261-1204 Digital hydraulic tester
L
799-101-5220 Nipple (10 × 1.25 mm)
2
07002-11023
Measurement
a Measurement of the oil pressure in the pump PC
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 PC valve output pressure
(servo piston inlet pressure)
a PC valve output pressure (servo piston inlet
pressure) is measured along with that of the
pump discharge pressure and the result of
the two is compared to each other.
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)
(2): For the rear pump discharge pressure
q
(situated in the front side of the machine)
q (3): For the front pump PC valve output
pressure
q (4): For the rear pump PC valve output
pressure
40
Part name
O-ring
30 Testing and adjusting
2) Fit nipple L2 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
2
}.
PC300, 350-8