Testing And Adjusting Control Circuit Pressure (Output Pressure Of Self Pressure Reducing Valve)10; Testing And Adjusting Control Circuit Pressure (Output Pressure Of Self Pressure Reducing Valve) - Komatsu Galeo PC800-8 Shop Manual

SEN00788-02
Testing and adjusting control
circuit pressure (output pres-
sure of self pressure reducing
valve)
a Testing and adjusting instruments for control cir-
cuit pressure
Symbol Part Number
799-101-5002
L
790-261-1204
Measuring
a Measure the control circuit pressure under the
following condition.
• Hydraulic oil temperature: 45 – 55°C
k Lower the work equipment to the ground and
stop the engine. Then, operate the control le-
vers several times to release the residual
pressure in the piping and loosen the oil filler
cap of the hydraulic tank slowly to release
the internal pressure of the hydraulic tank.
1. Open the pump room cover.
2. Connect oil pressure gauge [1] of hydraulic
tester L to oil pressure pickup nipple (1) of the
main pump.
10
Part Name
Hydraulic tester
Digital hydraulic tester
3. While running the engine at high idle, set the
work equipment, swing and travel levers in neu-
tral and measure the oil pressure.
Adjusting
a If the output pressure of the self pressure reduc-
ing valve (control circuit pressure) is abnormal,
adjust self pressure reducing valve (2) accord-
ing to the following procedure.
1) Open the pump room cover.
2) While fixing adjustment screw (3), loosen
locknut (4).
3) Rotate adjustment screw (3) to adjust the
pressure.
a Target value:
3.2 – 3.5 MPa {33 – 36 kg/cm
a If the adjustment screw is
• turned to the right, the pressure ris-
es.
• turned to the left, the pressure low-
ers.
a Change of pressure in 45° turn of adjust-
ment screw:
4) While fixing adjustment screw (3), tighten
3 Locknut (4):
locknut (4).
30 Testing and adjusting
0.29 MPa {3.0 kg/cm
49 – 69 Nm {5 – 7 kg/cm
PC800, 850-8
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