Testing And Adjusting Oil Pressure In Pump Pc Control Circuit - Komatsu PC130-7 Shop Manual

TESTING AND ADJUSTING
TESTING AND ADJUSTING
OIL PRESSURE IN PUMP PC
CONTROL CIRCUIT
a Testing and adjusting instruments for oil pressure
in pump PC control circuit
Symbol Part No.
799-101-5002
1
790-261-1203
K
799-101-5220
2
07002-11023
MEASURING
Measuring PC valve output pressure (servo pis-
ton inlet pressure)
a Before measuring the PC valve output pressure
(servo piston inlet pressure), check that the oil
pressure in the work equipment, swing, and
travel circuits and the basic pressure in the con-
trol circuit are normal.
a Measure the PC valve output pressure (servo
piston inlet pressure) and pump discharge pres-
sure simultaneously and compare them.
k Lower the work equipment to the ground and
stop the engine.
several times to release the residual pressure
in the piping, and then loosen the oil filler cap of
the hydraulic tank slowly to release the internal
pressure of the hydraulic tank.
1. Remove the top cover of the control valve and
open the pump room cover.
2. Remove oil pressure pickup plugs (1) and (2).
• (1): Pump discharge pressure pickup plug (at
top of control valve)
20-126
(1)
Part name
Hydraulic tester
Digital hydraulic tester
Nipple (10 x 1.25 mm)
O-ring
Operate the control levers
TESTING AND ADJUSTING OIL PRESSURE
IN PUMP PC CONTROL CIRCUIT
• (2): PC valve output pressure pickup plug (at
top of hydraulic pump)
3. Install nipple K2 and connect it to oil pressure
gauge [1] of hydraulic tester K1.
a Use the oil pressure gauge of 58.8 MPa {600
2
kg/cm }.
• The drawing shows the pump discharge
pressure side.
• The drawing shows the PC valve output
pressure side.
4. Run the engine and heighten the hydraulic oil
temperature to 45 – 55°C.
PC130-7