Testing And Adjusting Oil Pressure In Pump Pc Control Circuit - Komatsu PC88MR-10 Shop Manual

Testing and adjusting oil pressure in pump PC control circuit

00-A)
a Testing tools
Sym-
Part No.
bol
799-101-5002 Hydraulic tester
1
790-261-1205 Digital hydraulic tester
N
799-101-5220 Nipple (10 x 1.25 mm)
2
07002-11023 O-ring
Place the machine on a level ground, lower
the work equipment to the ground, and
release the remaining pressure in the
hydraulic circuit. For details, see "Releasing
remaining pressure in hydraulic circuit".
Testing
(PC88MR-C2A3-362-K-00-A)
a Before testing the oil pressure in the pump PC
control circuit, check that the oil pressure in the
work equipment and travel circuits and the
source pressure of the control circuit are proper.
a Check this item under the following conditions.
Hydraulic oil temperature: 45 to 55°C
1. Measurement of PC valve output pressure
(servo piston inlet pressure)
a To measure the PC valve output pressure
(servo piston inlet pressure), measure the
pump discharge pressure simultaneously
and compare them.
1) Open the right side cover, open the engine
hood and remove oil pressure pickup plugs
(1) and (2).
(1): Pump discharge pressure pickup
plug
(2): PC valve output pressure pickup plug
PC88MR-10
Part name
30 Testing and adjusting
2) Install nipple N2 and connect it to oil
pressure gauge [1] of hydraulic tester N1.
a Use the oil pressure gauge of 60 MPa
{600 kg/cm 2 }.
3) Start the engine, and operate the arm
cylinder to arm IN stroke end.
4) Set the working mode to Power Mode (P).
5) Run the engine at high idle, operate the left
work equipment control lever to relieve the
arm cylinder circuit at IN end, and measure
the oil pressure.
Hydraulic system
(PC88MR-C2A3-360-K-
30-49