Thermo King SLXi Spectrum, Maintenance Manual

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Engine Maintenance 9-6
ENGINE COOLING SYSTEM
The engine uses a closed, circulating type, pressurised cooling system. Correct engine temperatures are controlled and maintained
by a radiator, fan and thermostat. The coolant is circulated through the system by a belt-driven centrifugal pump. The pump draws
the coolant from the side of the radiator, circulates it through the cylinder block and head, then back to the radiator. A thermostat
mounted in the water outlet from the cylinder head to the radiator automatically maintains coolant temperature within the
specified temperature range.
All water-cooled engines are shipped from the factory with a 50% permanent type antifreeze concentrate and 50% water mixture
in the engine cooling system. This provides the following:
1. Prevents freezing down to -34.0 C.
2. Retards rust and mineral scale that can cause the engine to overheat.
3. Retards corrosion (acid) that can an attack accumulator tank, water tubes, radiator and engine block plug.
4. Provides lubrication for the water pump seal.
ANTIFREEZE MAINTENANCE PROCEDURE
Regular inspection is required to verify the condition of the antifreeze. Inhibitors become worn out and must be replaced by
changing the antifreeze. Change green or blue-green engine coolant every two year.s Change ELC (red) engine coolant every 5
years or 12,000 hours (whichever occurs first). Do not mix green or blue-green engine coolant with ELC (red) engine coolant.
See “ELC (Extended Life Coolant)” on the following page for more information about ELC.
The factory recommended the use of a 50/50 antifreeze mixture in all units even if they are not exposed to freezing temperatures.
This anitfreeze mixture will provide the required corrosion protection and lubrication for the water pump.