Large Shock Is Made When Upper Structure Stops Swinging; Large Sound Is Made When Upper Structure Stops Swinging - Komatsu PC210-8 Shop Manual

40 Troubleshooting
H-26 Large shock is made when upper structure stops swinging
Trouble

• Large shock is made when upper structure stops swinging.

Related
• Carry out all troubleshooting in power mode (P) of working mode.
information
Malfunction of swing PPC
1
valve
Possible
causes and
standard value
in normal state
Clogging of swing PPC slow
2
return valve
Malfunction of swing motor
3
(shockless valve)
H-27 Large sound is made when upper structure stops swinging
Trouble

• Large sound is made when upper structure stops swinging.

Related
• Carry out all troubleshooting in power mode (P) of working mode.
information
Malfunction of back pressure
1
valve
Malfunction of swing motor
2
Possible (safety valve)
causes and
standard value
Malfunction of swing motor
3
in normal state
(suction valve)
4 Defective swing machinery
PC210, 230, 240-8
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
Shockless valve of swing motor may have malfunction. Check it
directly.
Cause Standard value in normal state/Remarks on troubleshooting
Back pressure valve may have malfunction. Check it directly.
Safety valve of swing motor may have malfunction. Check it
directly.
Suction valve of swing motor may have malfunction. Check it
directly.
a
Swing machinery may have internal defect. Check it directly.
a
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 con-
dition.
Suction valves on right side and left side may be checked by
replacing them with each other and seeing change of condition.
It may be checked by abnormal sound, abnormal heating,
metal chips in drain oil, etc.
UEN00245-02
PPC valve output pressure
0 MPa
2
{0 kg/cm }
2.84 – 3.43 MPa
2
{29 – 35 kg/cm }
1
1
29