Komatsu Galeo PC800-8, Shop Manual

Page: 802 / 1117

8
PC800, 850-8
SEN00794-02
40 Troubleshooting
H-1 Speed or power of all work equipment, travel, and swing is low
Failure
phenomenon
• Speed or power of all work equipment, travel, and swing is low
Relative
information
• Measure the speed of the work equipment, travel, and swing speed and check that all of them are slow
(or their power is low).
• Check that abnormal sound is not heard from around the pump.
(If abnormal sound is heard, carry out the related troubleshooting.)
• Check that the machine does not deviate.
(If the machine deviates, carry out the related troubleshooting.)
• Carry out all the troubleshooting in working mode P.
• If failure code related to pump control is also displayed, carry out troubleshooting for it first.
Possible causes
and standard
value in normal
state
Cause Standard value in normalcy and references for troubleshooting
1 Defective engine unit
a
Run the engine at high idle during troubleshooting.
Heavy lift switch and right work
equipment control lever
Engine speed
Heavy lift switch OFF +
Boom RAISE relief
Above 1,700 rpm
Heavy lift switch ON + Boom
RAISE relief
Above 1,700 rpm
2
Malfunction of self
pressure reducing valve
a
Keep the engine stopped for the preparations, and run it at high idle
during troubleshooting.
Control levers Control relief pressure
All levers in neutral
3.24 MPa
{33 kg/cm 2 }
If fan is rotating and pressure at self pressure reducing valve is low, self
pressure reducing valve may be malfunctioning. Check self pressure
reducing valve directly (It cannot be adjusted).
3
Leakage in control
system devices
a
Stop the engine and block (1) – (9) in Fig. 1 in order. Run the engine
at high idle and check.
Control levers Control relief pressure
All levers in neutral
3.24 MPa
{33 kg/cm 2 }
4
Wrong adjustment or mal-
function of main relief valve
a
Keep the engine stopped for the preparations, and run it at high idle
during troubleshooting.
Heavy lift switch and right work
equipment control lever
Main relief pressure
Heavy lift switch OFF +
Boom RAISE relief
32.4 MPa
{330 kg/cm 2 }
Heavy lift switch ON +
Boom RAISE relief
33.8 MPa
{345 kg/cm 2 }
If the oil pressure is still abnormal after adjustment, the main relief valve
(on the low-pressure set side and high-pressure set side) may be defec-
tive. Check the main relief valve directly.
+0.49
0
+5
0
+0.49
0
+5
0
+1.0
–2.0
+10
–20
+1.0
–2.0
+10
–20