Carrier NDK33BN0KB, Operation & Service Manual

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62-61753-21 7-6
Alarm
NO.
Steps ALARM / CAUSE CORRECTIVE ACTION
12 HIGH COOLANT TEMPERATURE (Continued)
5 Check Engine Cooling System
a. Compare actual engine tempera-
ture to the microprocessor reading.
Temperature must be within ±11.1°C (±20°F).
b. Test operation of engine coolant
thermostat.
Must operate correctly. Refer to engine manual
c. Check water pump operation. No seepage at weep hole. Bearings tight and quiet.
Impeller firmly attached to shaft.
d. Check cooling system for scale,
sludge, rust, etc.
Coolant must be clean & clear with foreign particles or
substances in it. Flush & clean the coolant system as
necessary.
e. Check water pump bypass hose to
thermostat housing for internal
blockage.
Must be clear and open.