Testing And Adjusting Oil Pressure In Work Equipment And Travel Circuits - Komatsu PC88MR-10 Shop Manual

30 Testing and adjusting
Hydraulic system
Testing and adjusting oil pressure in work equipment and travel
circuits
(PC88MR-C000-360-K-00-A)
a Testing tools
Sym-
Part No.
bol
799-101-5002 Hydraulic tester
1
790-261-1205 Digital hydraulic tester
K
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-C000-362-K-00-A)
a The oil pressures (pump discharged pressures)
of the work equipment and travel circuits can be
checked with the monitoring function of the
machine monitor (For details, see SPECIAL
FUNCTIONS OF MACHINE MONITOR).
Monitoring code: 01100 "Pump pressure"
a Check this item under the following conditions.
Hydraulic oil temperature: 45 to 55°C
1. Preparation
1) Remove cover (6) on the right side of the
control lever, and remove pressure pickup
plugs (1) and (2).
(1): Pump discharged pressure port (1)
pickup plug
(2): Pump discharged pressure port (2)
pickup plug
30-42
Part name
2) Install nipple K2 and connect oil pressure
gauge [1] of hydraulic tester K1.
a Use the oil pressure gauge of 60 MPa .
2. Testing unload pressure
1) Start the engine, set the working mode to
power mode (P), and turn the auto
deceleration OFF.
2) Run the engine at high idle, set all of control
levers and pedals of work equipment and
travel in neutral, and measure the oil
pressure.
a The oil pressure at which the unload
valve unloads is displayed.
3. Testing the work equipment relief pressure
1) Start the engine, and operate the cylinder to
be measured to the stroke end.
PC88MR-10