Upper Structure Overruns Remarkably When It Stops Swinging - Komatsu PC210-8 Shop Manual

UEN00245-02
H-25 Upper structure overruns remarkably when it stops swinging
Trouble (1) Upper structure overruns remarkably when it stops swinging in both directions.
Related
• Carry out all troubleshooting in power mode (P) of working mode.
information
Defective adjustment or
1 malfunction of swing motor
Possible
(safety valve)
causes and
standard value
in normal state
2 Defective swing motor
Trouble (2) Upper structure overruns remarkably when it stops swinging in only one direction.
Related
• Carry out all troubleshooting in power mode (P) of working mode.
information
Malfunction of swing PPC
1
valve
Possible
Clogging of swing PPC slow
2
causes and
return valve
standard value
in normal state
Malfunction of swing control
3
valve (spool)
Malfunction of swing motor
4
(suction valve)
Malfunction of swing motor
5
(check valve)
28
Cause Standard value in normal state/Remarks on troubleshooting
• Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Swing lock switch
If oil pressure does not become normal after adjustment, swing
motor safety valve may have malfunction or internal defect. Check
safety valve directly.
a
Swing lock switch
Cause Standard value in normal state/Remarks on troubleshooting
a
Left work equipment control lever
Swing PPC slow return valve may have malfunction. Check it
directly.
a
Spool of swing control valve may have malfunction. Check it
directly.
Suction valve of swing motor may have malfunction. Check it
directly.
a
Check valve of swing motor may have malfunction. Check it
directly.
a
Left work equipment
control lever
ON Swing relief
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Left work equipment
control lever
ON Swing relief
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Neutral
Left swing
Right swing
Slow return valves on right side and left side may be checked
by replacing them with each other and seeing change of condi-
tion.
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.
40 Troubleshooting
Swing relief pressure
28.9 – 32.9 MPa
{295 – 335 kg/cm
Leakage from swing
motor
Max. 10 l/min
PPC valve output pressure
0 MPa
2
{0 kg/cm }
2.84 – 3.43 MPa
2
{29 – 35 kg/cm }
PC210, 230, 240-8
1
2
}