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

SEN04124-00
H-6 Speed or power of boom is low
Trouble

• Speed or power of boom is low.

Related
• Conduct the troubleshooting in working mode P.
information
Malfunction of right PPC
1
valve (boom circuit)
Malfunction of pump merge-
2
divider solenoid valve
Malfunction of pump merge-
3
divider valve
Possible causes
Malfunction of boom control
4
and standard
valve (spool)
value in normal
state
Malfunction of boom control
5 valve (pressure compensa-
tion valve)
Malfunction of boom control
6
valve (lock valve)
Malfunction or defective
7 sealing of boom control valve
(safety-suction valve)
Malfunction or defective
8 sealing of boom control valve
(suction valve)
Malfunction or defective
9 sealing of centralized safety-
suction valve
10 Boom cylinder defective
10
Cause Standard value in normal state/Remarks on troubleshooting
a
Right work equipment control
a
The pump merge-divider valve of the control valve may have a
malfunction. Check it directly.
The spool of the boom control valve may have a malfunction.
Check it directly (Including stroke limiting mechanism on RAISE
side).
The pressure compensation valve of the boom control valve may
have a malfunction. Check it directly.
The lock valve of the boom control valve may have a malfunction.
Check it directly.
The safety-suction valve of the boom control valve (on the head
side) may have a malfunction or its sealing may be defective.
Check it directly.
The suction valve of the boom control valve (on the bottom side)
may have a malfunction or its sealing may be defective. Check it
directly.
The centralized safety-suction valve of the control valve may have
a malfunction or its sealing may be defective. Check it directly.
a
Relieved in RAISE direction
Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
lever
NEUTRAL
Boom RAISE position
Boom LOWER 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.
Boom cylinder
40 Troubleshooting
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
PC130-8
1