Ingersoll-Rand Thermo King SGCM 4000, Maintenance Manual, Page: 130 / 181

Engine Maintenance
129
NOTE: The use of 50/50 percent pre-mixed Extended Life Coolant (ELC) is recommended to assure
that de-ionized water is being used. If 100 percent full strength concentrate is used, de-ionized or
distilled water is recommended over tap water to insure the integrity of the cooling system is
maintained.
Antifreeze Maintenance Procedure
As with all equipment containing antifreeze, periodic inspection on a regular basis is required to verify
the condition of the antifreeze. Inhibitors become worn out and must be replaced by changing the
antifreeze. Change ELC (red) engine coolant every five 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 page 128 for more information about ELC.
The factory recommends the use of a 50/50 antifreeze mixture in all units even if they are not exposed to
freezing temperatures. This antifreeze mixture will provide the required corrosion protection and
lubrication for the water pump.
Checking the Antifreeze
Check the solution concentration by using a temperature compensated antifreeze hydrometer or a
refractometer (P/N 204-754) designed for testing antifreeze. Maintain a minimum of 50 percent
permanent type antifreeze concentrate and 50 percent water solution to provide protection to -30 F (-34
C). Do not mix antifreeze stronger than 68 percent permanent type coolant concentrate and 32 percent
water for use in extreme temperatures.
Changing the Antifreeze
1. Run the engine until it is up to its normal operating temperature. Stop the unit.
2. Open the engine block drain (located off water intake tube) and completely drain the coolant. Observe
the coolant color. If the coolant is dirty, proceed with a, b, and c. Otherwise go to 3.
a. Run clear water into the radiator and allow it to drain out of the block until it is clear.
b. Close the block drain and install a commercially available radiator and block flushing agent, and
operate the unit in accordance with instructions of the flushing agent manufacturer.
c. Open the engine block drain to drain the water and flushing solution.
3. Run clear water into the radiator, and allow it to drain out of the block until it is clear.
4. Inspect all hoses for deterioration and hose clamp tightness. Replace if necessary.
5. Loosen the water pump belt. Check the water pump bearing for looseness.
6. Inspect the radiator cap. Replace the cap if the gasket shows any signs of deterioration.
7. If using ELC concentrate, mix one gallon of ELC concentrate and one gallon of de-ionized or distilled
water in a container to make a 50/50 mixture. (Do not add antifreeze and then add water to the unit.
This procedure may not give a true 50/50 mixture because the exact cooling system capacity may not
always be known.)
CAUTION: Avoid direct contact with hot
coolant.
CAUTION: Avoid direct contact with hot
coolant.