Komatsu WA380-8 Operation & Maintenance Manual page 318

TROUBLES AND ACTIONS
Problem
Excessive bubbles are in oil.
Oil pressure is low.
Movement of cylinder is irregular.
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
Engine oil pressure caution lamp
lights up.
Steam spurts out from top of radiator
(pressure valve).
Indicator of engine coolant tempera-
ture gauge is in red range
Engine coolant temperature caution
lamp lights up.
3-254
Main causes
Poor quality of oil
Hydraulic oil in the hydraulic tank is
insufficient.
Air is in oil system.
Pump sucks air because of insuffi-
cient hydraulic oil in the hydraulic
tank.
Hydraulic oil in the hydraulic tank is
insufficient.
Main causes
Lowered oil level in engine oil pan
(sucking in air)
Improper oil is used. (Viscosity is im-
proper.)
Clogged oil filter cartridge
Oil leakage due to improper connec-
tion or breakage of oil pipe or pipe
joint
Defective engine oil pressure sensor
Defective monitor
Lowered coolant level, leakage of
coolant
Defective fan pump or motor
Accumulation of dirt or scale in cool-
ing system
Clogged radiator fins or damaged fin
Defective thermostat
Defective sealing of thermostat
Loose radiator filler cap
(In high altitude operation)
Defective coolant temperature gauge
Defective coolant level sensor
Defective monitor
Remedy
Replace the oil with oil of good quali-
ty.
Add oil to specified level. See EVERY
100 HOURS MAINTENANCE.
Replace the filter. See Every "EVERY
2000 HOURS MAINTENANCE".
Add oil referring to "EVERY 100
HOURS MAINTENANCE", and bleed
air referring to "EVERY 2000 HOURS
MAINTENANCE".
Add oil to specified level. See EVERY
100 HOURS MAINTENANCE.
Remedy
Set oil to specified level. See
CHECKS BEFORE STARTING.
Replace oil. See USE OF FUEL,
METHOD FOR USING FUEL, COOL-
ANT AND LUBRICANTS ACCORD-
ING TO AMBIENT TEMPERATURE.
Replace cartridge. See EVERY 500
HOURS MAINTENANCE.
Check, repair. (*)
Replace sensor. (*)
Replace monitor. (*)
Check, add coolant, or repair. See
WHEN REQUIRED.
Check, repair. (*)
Check, add coolant, or repair. See
WHEN REQUIRED.
Clean or repair them. See WHEN
REQUIRED.
Replace thermostat. (*)
Replace thermostat seal. (*)
Tighten cap or replace packing.
Replace coolant temperature gauge.
(*)
Replace sensor.
Replace. (*)
OPERATION