Speed Or Power Of Arm Is Low - Komatsu PC130-8 Shop Manual

40 Troubleshooting
H-7 Speed or power of arm is low
Trouble

• Speed or power of arm is low.

Related
• Conduct the troubleshooting in working mode P.
information
Malfunction of left PPC valve
1
(arm circuit)
Malfunction of pump merge-
2
divider solenoid valve
Possible causes
Malfunction of pump merge-
3
and standard
divider valve
value in normal
state
Malfunction of arm control
4
valve (spool)
Malfunction of arm control
5 valve (pressure compensa-
tion valve)
Malfunction or defective
6 sealing of arm control valve
(safety-suction valves)
Malfunction or defective
7 sealing of centralized safety-
suction valve
8 Arm cylinder defective
PC130-8
Cause
a
Left work equipment control
a
The pump merge-divider valve of the control valve may have a
malfunction. Check it directly.
The spool of the arm control valve may have a malfunction. Check
it directly (Including stroke limiting mechanisms on IN side and
OUT side).
The pressure compensation valve of the arm control valve may
have a malfunction. Check it directly.
The safety-suction valves of the arm control valve (on the bottom
side and head side) may have a malfunction or their sealing may
be defective. Check them directly.
The centralized safety-suction valve of the control valve may have
a malfunction or its sealing may be defective. Check it directly.
a
Standard value in normal state/Remarks on troubleshooting
Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
lever
NEUTRAL
Arm IN position
Arm OUT position
Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
Control levers
All levers in NEUTRAL
Position for travel only
(On either or both sides)
Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
Arm cylinder
Relieved in IN direction
SEN04124-00
PPC valve output pressure
0 MPa {0 kg/cm }
2
Above 2.7 MPa
{Above 28 kg/cm }
2
Solenoid output pressure
0 MPa {0 kg/cm }
2
2.84 – 3.43 MPa
{29 – 35 kg/cm }
2
Leakage from cylinder
15 cc/min
1
11