Auto-Decelerator Does Not Operate; Fine Control Performance Or Response Is Low - Komatsu PC130-7 Shop Manual

TROUBLESHOOTING
H-5 Auto-decelerator does not operate
Trouble

• Auto-decelerator does not operate.

• Apply this troubleshooting if the auto-decelerator does not operate when the travel lever is operated.
Related (The shuttle valve (in the PPC valve) is installed between the PPC valve and oil pressure switch of only
information in the travel circuit.)
• Carry out the troubleshooting in working mode A.
Possible causes
and standard
Malfunction of travel PPC
value in normal
1
valve (shuttle valve)
state
H-6 Fine control performance or response is low
Trouble

• Fine control performance or response is low.

Related
• Carry out the troubleshooting in working mode A.
information
Clogging of LS circuit
1
orifice
Possible causes
and standard
value in normal
Defective adjustment or
2
state
malfunction LS valve
3 Defective servo piston
PC130-7
Cause Standard value in normal state/Remarks on troubleshooting
aPrepare with engine stopped, then run engine at high idling and carry
out troubleshooting.
Cause Standard value in normal state/Remarks on troubleshooting
The LS circuit may be clogged. Check it directly.
aPrepare with engine stopped, then run engine at high idling and carry
out troubleshooting.
Measured oil pressure
Pump discharge
LS valve output
If the oil pressure does not become normal after adjustment, the LS
valve may have a malfunction or a defect in it. Check the LS valve
directly.
The servo piston may have a malfunction. Check it directly.
Travel lever
Neutral position
Travel position
All levers in neutral
pressure
Almost same pressure
pressure
H-5, H-6
PPC valve output pressure
0 MPa
2
{0 kg/cm }
2.84 – 3.43 MPa
2
{29 – 35 kg/cm }
Oil pressure ratio
Either track shoe
driven idle (Full stroke)
1
0.6 (3/5)
20-509
(1)