Engine Cooling System - Daewoo Mega 250-V Operation And Maintenance Manua

ENGINE COOLING SYSTEM

GENERAL
Keeping an engine's cooling system in peak operating condition, can have many benefits to keeping a
machine in good operating condition. A properly functioning cooling system will; improve fuel efficiency,
reduce engine wear, and extend component life.
Always use distilled water in the radiator. Contaminants in tap water neutralize the corrosion inhibitor
components. If tap water must be used, it should not exceed 300 ppm hardness, or contain more than 100
ppm of either chloride or sulfate. Water that has been treated with a water softener also contains salt that
will cause corrosion of components. Water from creeks and stagnant pools usually contains dirt, minerals
and/or organic material that are deposited in the cooling system and impair cooling efficiency. Distilled
water is the best.
Engine overheating is often caused by bent or clogged radiator fins. The spaces between the fins can be
cleaned by use of air or water under pressure. When straightening bent fins, use care not to damage the
tubes or break the bond between the fins and the tubes.
Pressure at air nozzle must not exceed 30 PSI (2.1 kg/cm
compressed air.
Do not pour cold water into radiator when engine is very hot and water level is below the top of
the tubes. Such action could result in damage to engine cylinder heads.
Heavy duty diesel engines require a balanced mixture of water and antifreeze. Drain and replace the
mixture every year or 2,000 Hours of operation, which ever comes first. This will eliminate buildup of
harmful chemicals.
Antifreeze is essential in any climate. It broadens the operating temperature range by lowering the
coolant's freezing point and by raising its boiling point. Do not use more than 50% antifreeze in the mixture
unless additional freeze protection is required. Never use more than 68% antifreeze under any condition.
Types of Antifreeze
There are two main classifications of antifreeze available on the market today.
1. Ethylene Glycol - Standard Life Antifreeze
2. Propylene Glycol - Extended Life Antifreeze
Ethylene glycol (standard life antifreeze) has been on the market for many years. Its chemical properties
do not provide the improved corrosion resistance that propylene glycol (extended life antifreeze) does.
Ethylene glycol is also very hazardous to the environment, people and animals. Daewoo recommends that
ethylene glycol be replaced with propylene glycol.
The newer propylene glycol antifreeze comes in many different colors. Some of the colors are pink, red,
orange and yellow. There are even some that come in a blue-green color. The blue-green color makes it
very difficult to tell the difference of what type of antifreeze is in a cooling system. The colors are only a dye
added to the clear antifreeze. Do not rely on color. Keep careful machine records of what brand and type of
antifreeze is used in the unit. If you are unsure of what type of antifreeze is in the system, drain and flush
the system.
4-60 Inspection, Maintenance and Adjustment
WARNING!
2
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K1000896E Operation and Maintenance Manual