Engine coolant glycol is normally either ethylene or
propylene. Glycol raises the boiling point of water to
help prevent boil-over, provides freeze protection, helps
prevent water pump cavitation, and reduces cylinder
For ambient temperatures requiring lower freeze
protection (higher than 50 percent glycol), use
ethylene glycol. DO NOT use propylene glycol.
Proper freeze/boll protection requires the proper ratio of
glycol and acceptable water. Use the following charts to
determine glycol concentrations to mix with acceptable
Use the 1U-7298 Coolant Tester (-C) or the 1U-7297
Coolant Tester (-F) to check the coolant solution
periodically to ensure adequate freeze/boil protection.
The refractometers give immediate, accurate readings
and can be used with ethylene or propylene glycol.
NOTE: For more detailed specifications, refer to:
Know Your Cooling System, SEBD0518, and
Coolant and Your Engine, SEBD0970, or
contact your Caterpillar dealer.
Preferred - Caterpillar's Long Life Coolant/Antifreeze
Acceptable - 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.
Permitted - A mixture of acceptable water and a
supplemental coolant additive, where freeze protection is
Unacceptable - Any high silicate coolant that is classified
as meeting ASTM D3306.
Most commercial engine coolant/antifreezes are
formulated for gasoline engine applications and
have high silicate content. High silicates can lead to
cylinder liner cavitation and corrosion. Caterpillar
DOES· NOT recommend high silicate coolants or
NOTE: Due to individual engine applications, engine
cooling system maintenance practices may
need periodic evaluation.
Never operate without thermostats in the cooling
system. Thermostats maintain the engine coolant at
the proper operating temperature. Cooling system
problems can arise without thermostats.
Never add coolant to an overheated engine. Allow
the engine to cool first. Do not add coolant too
quickly. Filling the cooling system at over 19 L
(5 US gal) per minute can create air pockets in the
cooling system. Engine damage can result.
When filling or adding coolant to the system, premix the
coolant solution prior to pouring it into the cooling
system. Pure, undiluted glycol will freeze at -23C
(-10F). Use a coolant solution that is in a range which
will provide protection to the lowest expected outside
(ambient) temperature and provide the required boil-over
Cooling System Specifications