3Com Caterpillar Commercial Diesel Engine SEBU6251-06 - Manual (Page 24)

24
Maintenance Section
Cooling System Specifications
Cooling System
Specifications
i01111669
General Coolant Information
SMCS Code: 1350; 1395
NOTICE
Never add coolant to an overheated engine. Engine
damage could result. Allow the engine to cool first.
NOTICE
If the engine is to be stored in, or shipped to an area
with below freezing temperatures, the cooling system
must be either protected to the lowest outside temper-
ature or drained completely to prevent damage.
NOTICE
In cold weather, frequently check the specific gravity
of the coolant solution to ensure adequate protection.
Clean the cooling system for the following reasons:
• Contamination of the cooling system
• Overheating of the engine
• Foaming of the coolant
Note: Air pockets can form in the cooling system if
the cooling system is filled at a rate that is greater
than 20 L (5 US gal) per minute.
After you drain the cooling system and after you
refill the cooling system, operate the engine.
Operate the engine without the filler cap until the
coolant reaches normal operating temperature and
the coolant level stabilizes. Ensure that the coolant
is maintained to the proper level.
NOTICE
Never operate an engine without water temperature
regulators in the cooling system. Water temperature
regulators help to maintain the engine coolant at the
proper operating temperature. Cooling system prob-
lems can develop without water temperature regula-
tors.
Refer to Special Instruction, SEBD0518, “Know
Your Cooling System” and Special Instruction,
SEBD0970, “Coolant and Your Engine” for more
detailed information.
Many engine failures are related to the cooling
system. The following problems are related to
cooling system failures: overheating, leakage of the
water pump, plugged radiators or heat exchangers,
and pitting of the cylinder liners.
These failures can be avoided with proper cooling
system maintenance. Cooling system maintenance
is as important as maintenance of the fuel system
and the lubrication system. Quality of the coolant
is as important as the quality of the fuel and the
lubricating oil.
Coolant is normally composed of three elements:
water, additives, and glycol.
Water
NOTICE
All Caterpillar diesel engines equipped with air-to-air
aftercooling (ATAAC) require a minimum of 30 percent
glycol to prevent water pump cavitation.
NOTICE
Never use water alone without Supplemental Coolant
Additives (SCA) or without inhibited coolant. Water
alone is corrosive at engine operating temperatures.
Water alone does not provide adequate protection
against boiling or freezing.
Water is used in the cooling system in order to
transfer heat.
Distilled water or deionized water is
recommended for use in engine cooling systems.
DO NOT use the following types of water in cooling
systems: hard water, softened water that has been
conditioned with salt, and sea water.
If distilled water or deionized water is not available,
use water with the properties that are listed in Table
9.