Komatsu PC200-8M0, Shop Manual, Page: 886 / 1254

500 Troubleshooting of hydraulic and mechanical system (H-mode)
Failure mode and cause table
40-500
6
PC200, 200LC, 220, 220LC-8M0
SEN06139-00
Failure mode and cause table
Failed parts
Engine system Da
mper
Tank Hydraulic pump Control valve
Failure mode
Hydr
aulic oil
Ca
p
st
ainer
Piston
pump
Ser
v
o piston
Pump swash plate senso
r
PC-EP
C
v
a
lve
PC valv
e
LS-
E
PC
valve
LS valve S
pool
Un
load valve
M
a
in
re
lief v
a
lv
e
Pre
s
sure compensation valve
Self-pr
essur
e reducing valve
LS lin
e throttle
Pump mer
ge-divider
main EPC va
lve
Pump mer
ge-divider
LS-EPC valve
Pump mer
ge-divider
main valve
Pump mer
ge-divider
LS valve
Boom thr
ottle EPC so
lenoid
Boom r
egener
ation
valve
Boom lock
valv
e
Any of wor
k
equipment,
swing and tr
avel
All of work equipment, swing and travel work slow or
lack power
q q q q q q q q q q q q
Engine speed lowers extremely or engine stalls
q q q q q q q q
All work equipment, travel, and swing systems do not
work.
q q q q
Unusual sound is heard from around hydraulic pump
q q q q
Fine control performance or response is poor
q q q q
W
o
rk equipment
Speed or power of boom is low
q q q q q q q q q
Speed or power of arm is low
q q q q q q
Speed or power of bucket is low
q q
Work equipment does not move in single operation
q
Hydraulic drift of work
equipment is large
Boom
q q
Arm
q q
Bucket
q q
Time lag of work equipment operation is large
q q q
Other wok equipment moves when one of work equip-
ment is relieved
q
One-touch power maximizing function does not work.
q
In combined operation of work equipment, equipment
having heavier load moves slower
q
Swing
and
boom
In combined operations of swing and boom RAISE,
boom rising speed is low
Swing
and
travel
Travel speed drops largely in combined operation of
swing and travel
T
ravel
Machine does not travel straight
q q q q q
Travel speed is low.
q q q q
Machine is hard to steer or travel power is low
q q q q q q
Travel speed does not change or travel speed is too
low or high
q
One of tracks does not run
Swing
Upper structure does not
swing
Upper structure swings
neither to the right nor left
q
Upper structure does not
swing in only one direction
q
Swing acceleration is poor
or swing speed is low
Poor or low for both of the
right and left
q
Poor or low for only in one
direction
q q
Upper structure overruns
considerably when it stops
swinging
Largely for both of the right
and left
Largely for only in one
direction
q
Shock is larger when upper structure stops swinging
Large unsual noise is heard when upper structure
stops swinging
Swing drift on a slope is
large
When swing brake works
When swing brake works
q q
At
ta
ch
-m
ent
Attachment circuit is not changed
Oil flow in attachment circuit cannot be changed