Speed Or Power Of Boom Is Low - Komatsu PC200-8M0 Shop Manual

500 Troubleshooting of hydraulic and mechanical system (H-mode)
H-6 Speed or power of boom is low
H-6 Speed or power of boom is low
q
Failure

Speed or power of boom is low

Related infor-
q
Perform all troubleshooting with working mode in power mode (P).
mation
Malfunction of right PPC
1
valve (boom circuit)
Malfunction of merge-divider
2
main EPC valve
Malfunction of merge-divider
3
LS-EPC valve
Malfunction of merge-divider
4
main valve
Malfunction of merge-divider
5
LS valve
Malfunction of boom control
6
valve (spool)
Malfunction of boom control
Probable
7 valve (pressure compensa-
causes and cri-
tion valve)
teria
Malfunction of boom control
8
valve (regeneration valve)
Malfunction of boom control
9
valve (lock valve)
Malfunction or defective
10 sealing of safety valve for
lock valve
Malfunction or defective
11 sealing of boom control
valve (suction valve)
Malfunction or defective
12 sealing of boom control
valve (safety-suction valve)
Malfunction of each control
13
valve (LS shuttle valve)
14 Defective boom cylinder
PC200, 200LC, 220, 220LC-8M0
Cause
a Be ready with engine stopped, then troubleshoot with engine at
full speed.
Right work equipment control
Merge-divider main EPC valve may malfunction. Check it.
Merge-divider LS-EPC valve may malfunction. Check it.
Merge-divider main valve may malfunction. Check it.
Merge-divider LS valve may malfunction. Check it.
Spool of boom control valve may malfunction. Check it.
Pressure compensation valve of boom control valve may malfunc-
tion. Check it.
Regeneration valve of boom control valve may malfunction. Check
it.
Lock valve of boom control valve may have malfunction.
Check it.
Safety valve for lock valve may malfunction or sealing may be
defective. Check it.
Suction valve of boom control valve may malfunction or sealing
may be defective. Check it.
Safety-suction valve of boom control valve may malfunction or
sealing may be defective. Check it.
LS shuttle valve of left travel control valve, bucket control valve, or
service control valve may malfunction. Check it.
a Be ready with engine stopped, then troubleshoot with engine at
full speed.
Right work equipment control
Criteria and troubleshooting procedure
lever
Neutral
Boom RAISE
Boom LOWER
lever
Boom RAISE relief
SEN06139-00
PPC valve output pressure
0 MPa
2
{0 kg/cm }
2.84 to 3.43 MPa
2
{29 to 35 kg/cm }
Leakage from boom cylinder
20 cc/min
40-500
15