Proper Antifreeze Concentrations
Use the table to determine concentrations of Diesel
Engine Antifreeze/Coolant to mix with acceptable water
and supplemental coolant additive.
ANTIFREEZE CONCENTRATIONS (GLYCOL)
Protection to -15C (5F)
30% antifreeze and
Protection to -23C (-9F)
40% antifreeze and
Protection to -37C (-35F)
50% antifreeze and
Protection to -51C (-60F)
60% antifreeze and
Any low silicate coolant that meets Truck Maintenance
Council (TMC) Recommended Practice (RP) 329, TMC
RP330, or ASTM D4985 requirements when used with
supplemental coolant additives is acceptable.
Caterpillar recommends a minimum of 30 percent glycol
to 70 percent water/supplemental coolant additive for
proper corrosion protection. All Caterpillar engines with
air-to-air aftercooling (ATAAC) require a minimum
concentration of 30 percent glycol to prevent water pump
While 30 percent glycol is the minimum acceptable
volume, Caterpillar prefers a 50 percent glycol and 50
percent water/supplemental coolant additive mixture for
When using Diesel Engine Antifreeze/Coolant, no
supplemental coolant additive is necessary on initial fill
because supplemental coolant additive is in the Diesel
additive must be added with commercial coolants
meeting ASTM D4985 at initial fill. Supplemental coolant
additive must be replenished with both Caterpillar Diesel
coolants at regular service intervals. Refer to the chart
for quantities of Caterpillar Liquid SCA to mix with ASTM
D4985 commercial coolants at initial fill.
LIQUID SUPPLEMENTAL COOLANT ADDITIVE
Initial Amount 1
(6-8 US gal)
(8-10 US gal)
(10-13 US gal)
(13-17 US gal)
(17-22 US gal)
(22-30 US gal)
(30-44 US gal)
(44-64 US gal)
Only use supplemental coolant additive If you are not using
Caterpillar Diesel Engine Antifreeze/Coolant (DEAC). Do
not exceed the maximum concentration of six percent.
Check the concentration with a supplemental coolant
additive test kit.
Supplemental Coolant Additive
Supplemental cooling system additive contains
alkali. To prevent personal injury, do not drink,
avoid contact with the skin and eyes.
The cooling system MUST contain supplemental
coolant additive for proper engine protection,
regardless of antifreeze concentration.
DO NOT mix Caterpillar's supplemental coolant
additive or coolant additive elements with another
manufacturer's products. Select a cooling system
treatment and use it exclusively.
Cooling System Specifications