Komatsu 75001, Руководство по ремонту

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SEN03850-00
WA250, 250PZ-6 40-600
21
600 Troubleshooting of engine (S-mode)
S-14 Coolant temperature becomes too high (overheating)
S-14 Coolant temperature becomes too high (overheating)
1
General causes why coolant temperature becomes too
high
q
Lack of cooling air (deformation, damage of fan)
q
Drop in heat dissipation efficiency
q
Problem in coolant circulation system
q
Rise in oil temperature in power train
o Carry out troubleshooting on applicable machine
Causes
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ise
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at
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Qu
e
st
io
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s
Confirm recent repair history
Degree of use of machine Operated for long period E E E E
Condition overheating
Sudden overheated Q w Q
Always tends to overheat Q Q w w Q
Coolant temperature gauge
Rises quickly
Q Q w
Does not go down from red range w
Radiator coolant level monitor indicates drop of coolant level Q w
Engine oil level has risen, oil is milky w w Q
Fan belt tension is low
w
C
h
ec
k it
em
s
When fan pulley is turned, it has play w
Milky oil is floating on coolant Q Q w
There are excessive air bubbles in radiator, coolant spurts back w
When light bulb is held behind radiator core, no light passes through
w
Radiator shroud, inside of underguard are clogged with dirt or mud w w
Coolant is leaking because of cracks in hose or loose clamps w
Coolant flows out from radiator overflow hose w
Fan belt whines under sudden acceleration
w
Power train oil temperature enters red range faster than engine coolant
temperature
w
T
rou
bl
es
ho
ot
in
g
When compression pressure is measured, it is found to be low
q
C
h
eck
di
re
ct
ly
Inspect cylinder block directly q q
Inspect oil cooler directly q
Temperature difference between upper and lower tanks of radiator is large q
When operation of thermostat is carried out, it does not open at cracking
temperature
q
Temperature difference between upper and lower tanks of radiator is slight q
Inspect radiator core directly q
When operation of radiator cap is carried out, its cracking pressure is low q
Inspect fan belt, pulley directly
q
When coolant temperature is measured, it is found to be normal q
Remedy
Re
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Re
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Re
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Re
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Ad
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Re
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Re
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Co
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Co
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Re
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Co
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Re
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