Komatsu PC30MR-5 Operation & Maintenance Manual page 255

OPERATION
Problem
Steam spurts out from top of radiator.
(pressure valve)
The graduation of engine coolant
temperature gauge indicates red
range.
(Caution lamp lights up and alarm
buzzer sounds at the same time.)
The graduation of the engine coolant
temperature gauge does not enter
the correct range even after the ma-
chine has been operated for a long
time.
Starting motor operates but engine
does not start.
Main causes
Lowered coolant level, leakage of
coolant
Loose fan belt
Accumulation of dirt or scale in cool-
ing system
Clogged radiator fins or damaged fin
Defective thermostat
Loose radiator filler cap (in high alti-
tude operation)
Lowered coolant level, leakage of
coolant
Loose fan belt
Accumulation of dirt or scale in cool-
ing system
Clogged radiator fins or damaged fin
Defective thermostat
Loose radiator filler cap (in high alti-
tude operation)
Defective thermostat
Lack of fuel
Air in fuel system
Water in fuel system
Defective fuel injection pump or de-
fective nozzle
Starting motor cranks engine slug-
gishly.
Preheating pilot lamp does not light
up.
Improper compression
(Incorrect valve clearance)
WENAM00150
TROUBLES AND ACTIONS
Remedy
Check, add coolant, repair by refer-
ring to CHECKS BEFORE START-
ING.
Adjust fan belt tension by referring to
EVERY 500 HOURS MAINTE-
NANCE.
Change coolant, flush inside of cool-
ing system by referring to WHEN RE-
QUIRED.
Clean or repair by referring to EVERY
500 HOURS MAINTENANCE.
Replace thermostat. (*)
Tighten the cap or replace packing.
Check, add coolant, repair by refer-
ring to CHECKS BEFORE START-
ING.
Adjust fan belt tension by referring to
EVERY 500 HOURS MAINTE-
NANCE.
Change coolant, flush inside of cool-
ing system by referring to WHEN RE-
QUIRED.
Clean or repair by referring to EVERY
500 HOURS MAINTENANCE.
Replace thermostat. (*)
Tighten the cap or replace packing.
Replace thermostat. (*)
Add fuel by referring to CHECKS BE-
FORE STARTING.
Bleed air by referring to EVERY 500
HOURS MAINTENANCE.
Drain the entrained water by referring
to WHEN REQUIRED, and CHECKS
BEFORE STARTING.
Replace pump or nozzle. (*)
See ELECTRIC PARTS, "Starting
motor cranks engine sluggishly".
See ELECTRIC PARTS, "Preheating
pilot lamp does not light up".
Adjust valve clearance. (*)
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