Komatsu PC130-8 User Manual

40 Troubleshooting SEN04125-02
PC130-8
23
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
Causes
Broken cylinder head, head gasket Holes caused by pitting Clogged, broken oil cooler Lack of coolant Broken water pump Defective operation of thermostat Clogged, crushed radiator fins Clogged radiator core Defective radiator cap (pressure valve) Slipping fan belt, worn fan pulley Defective coolant temperature gauge Rise in hydraulic oil temperature
Questions
Confirm recent repair history
Degree of use of machine Operated for long period EE EE
Condition overheating
Sudden overheated Qw Q
Always tends to overheat Qww Q
Coolant temperature gauge
Rises quickly Qw
Does not go down from red range w
Radiator coolant level monitor indicates drop of coolant level w
Engine oil level has risen, oil is milky wQ
Fan belt tension is low w
Check items
When fan pulley is turned, it has play w
Milky oil is floating on coolant 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 side are clogged with dirt or mud ww
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
Hydraulic oil temperature enters red range faster than engine coolant
temperature
w
Troubleshooting
When compression pressure is measured, it is found to be low q
Carry out troubleshooting
on H-mode
Inspect cylinder liner directly 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
Replace Replace Replace
Add
Replace Replace
Correct Correct
Replace
Correct
Replace
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Komatsu PC130-8 Specifications

General

Brand	Komatsu
Model	PC130-8
Category	Excavators
Language	English