Problem Main causes Remedy
Track comes off. Track too loose
Adjust track tension, see WHEN RE-
QUIRED.
Abnormal wear of sprocket Track too loose
Adjust track tension, see WHEN RE-
QUIRED.
Boom rises slowly or does not rise. Lack of hydraulic oil Set oil to specified level. See
CHECKS BEFORE STARTING.
Does not swing. Swing lock switch still applied Turn swing lock switch OFF.
Swing brake system error Check, adjust. (*)
When move of machine to safe place
is required, turn the swing parking
brake cancel switch to ON position
temporarily.
PHENOMENA AND ACTIONS FOR ENGINE RELATED PARTS
• For the remedies indicated with (*) in the remedy column, always contact your Komatsu distributor.
• In cases of problems or causes which are not listed below, ask your Komatsu distributor for repairs.
Problem
Main causes Remedy
Engine oil pressure caution lamp
lights up.
Lowered oil level in engine oil pan
(sucking in air)
Set oil to specified level. See
CHECKS BEFORE STARTING.
Improper oil is used. (Viscosity is im-
proper.)
Replace oil. See METHOD FOR US-
ING FUEL, COOLANT AND LUBRI-
CANTS ACCORDING TO AMBIENT
TEMPERATURE.
Clogged oil filter cartridge Replace cartridge. See EVERY 500
HOURS MAINTENANCE.
Oil leakage due to improper connec-
tion or breakage of oil pipe or pipe
joint
Check, repair. (*)
Defective engine oil pressure sensor Replace sensor. (*)
Defective monitor Replace monitor. (*)
Steam spurts out from top of radiator
(pressure valve).
Lowered coolant level, leakage of
coolant
Check, add coolant, repair. See
CHECKS BEFORE STARTING.
Dirt or scale accumulated in cooling
system
Change coolant, flush inside of cool-
ing system. See WHEN REQUIRED.
Clogged radiator fins or damaged fin Clean or repair. See EVERY 500
HOURS MAINTENANCE.
Defective thermostat Replace thermostat. (*)
Loosened radiator filler cap (in high
altitude operation)
Tighten cap or replace packing.
Defective coolant level sensor Replace sensor.
Defective monitor Replace monitor.
OPERATION TROUBLES AND ACTIONS
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