• Cavitation of the water pump
For optimum performance, Perkins recommends a
1:1 mixture of a water/glycol solution.
Note:
Use a mixture that will provide protection
against the lowest ambient temperature.
Note:
100 percent pure glycol will freeze at a
temperature of −13 °C (8.6 °F).
Most conventional antifreezes use ethylene glycol.
Propylene glycol may also be used. In a 1:1 mixture
with water, ethylene and propylene glycol provide
similar protection against freezing and boiling. Refer
to Table 9 and refer to table 10 .
Table 9
Ethylene Glycol
Concentration
Freeze Protection
50 Percent
−36 °C (−33 °F)
60 Percent
−51 °C (−60 °F)
NOTICE
Do not use propylene glycol in concentrations that
exceed 50 percent glycol because of the reduced
heat transfer capability of propylene glycol. Use ethyl-
ene glycol in conditions that require additional protec-
tion against boiling or freezing.
Table 10
Propylene Glycol
Concentration
Freeze Protection
50 Percent
−29 °C (−20 °F)
To check the concentration of glycol in the coolant,
measure the specific gravity of the coolant.
Note:
Some commercially available coolants are
based on alternative fluids, such as 1, 3-propanediol
(beta-propylene glycol, PDO), glycerin (glycerol) or
mixtures of these alternatives with ethylene/
propylene glycols. At the time of publication of this
document no industry standard exists for coolants
based on these chemicals. Until such standard/
specifications are published and evaluated by
Perkins, use of PDO, glycerine or other alternative
coolants is not recommended in Perkins diesel
engines.
Coolant Recommendations
• ELC
Extended Life Coolant
• SCA
Supplement Coolant Additive
• ASTM
American Society for Testing and
Materials
ELC - extended life coolant. A coolant that relies on
organic inhibitors for corrosion and cavitation
protection. Also called OAT coolant (Organic Acid
Technology).
SCA - supplemental coolant additive, concentrated
inorganic inhibitor package.
Extender - concentrated organic inhibitor package.
Conventional Coolant - a coolant that relies on
inorganic inhibitors for corrosion and cavitation
protection.
Hybrid Coolant - a coolant in which the corrosion and
cavitation protection is based on a mixture of organic
and inorganic inhibitors.
The following coolants are recommended for used in
Perkins diesel engines:
Preferred
– Perkins ELC
Acceptable
– A commercial heavy-duty antifreeze
that meets “ASTM D6210” or “ASTM D4985”
specifications.
NOTICE
The Perkins industrial engines with a NOx reduc-
tion system must be operated with a minimum
30% volume glycol-water mixture, Perkins recom-
mends 50% volume glycol-water mixture of water
and glycol. The 50% concentration allows the
NOx reduction system to operate correctly at
high ambient temperatures.
NOTICE
Do not use a commercial coolant/antifreeze that only
meets the ASTM D3306 specification. This type of
coolant/antifreeze is made for light automotive
applications.
Perkins recommends a 50% mixture of water and
glycol. This mixture of water and glycol will provide
optimum heavy-duty performance as an antifreeze.
This ratio may be changed to 40% water to 60%
glycol if extra freezing protection is required.
A mixture of SCA inhibitor and water is acceptable
but will not give the same level of corrosion, boiling
and, freezing protection as ELC. Perkins
recommends a 6 percent to 8 percent concentration
of SCA in those cooling systems. Distilled water or
deionized water is preferred.
Table 11
Coolant Service Life
Coolant Type
Service Life
(continued)
72
M0087475-03