Engine Cooling System Preventive Maintenance
– 144 – Y53-6008
Medium Duty (R10/06)
CAUTION: The engine cooling system has very
specific maintenance and inspection require-
ments. Failure to follow requirements can dam-
age the engine. Engine damage can include but
is not limited to:
• Freezing
• Boiling
• Corrosion
• Pitted cylinder liners
This information is found in the engine manufac-
turers owner’s manual. It is the owner’s respon-
sibility to follow all requirements listed in the
engine manufacturers owner’s manual.
What To Check In An ELC-filled Cooling System
ELC Concentration
Check the level of freeze/boilover protection, which is
determined by the ELC concentration. Use a glycol refrac-
tometer to determine glycol level. Add ELC to obtain the
ELC to water ratio required to provide the protection you
need. Use the chart below to help determine how much
ELC you need to add.
NOTE: Maximum recommended ELC concentra-
tion is 60% ELC and 40% water by volume (a 60/
40 coolant mixture). The minimum recommended
concentration is 40%.
In an ELC-filled cooling system, the freeze point should be
maintained between -30° F and -45° F (-34° C and -43° C)
