Komatsu ecot3 PC300LC-8 Shop Manual page 833

40 Troubleshooting
Trouble (2) • Upper structure swings only in one direction.
Related infor-
• Set the working mode in P-mode before start.
mation
Malfunction of swing PPC
1
valve
Possible causes
and standard Malfunction of swing control
2
value in normal valve (spool)
state
Defective seal of swing
3
motor (suction valve)
Defective seal of swing
4
motor (check valve)
PC300, 350-8
Cause Standard value in normal state/Remarks on troubleshooting
a
Spool of swing control valve may have malfunction. Check it directly.
Seal of suction valve of swing motor may be defective. Check it
directly.
a
Seal of check valve of swing motor may be defective. Check it
directly.
a
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Left lever
Neutral
Swing
Suction valves on right side and left side may be checked by
replacing them with each other and seeing change of condition.
Check valves on right side and left side may be checked by
replacing them with each other and seeing change of condition.
SEN02633-03
PPC valve output pressure
2
0 MPa {0 kg/cm }
Min. 2.7 MPa
2
{Min. 28 kg/cm }
27