Welcome to Cool Profit$ Magazine Online

About - Contact - Site Index - Sponsors - Subscribe

Table 1: Antifreeze and Coolant Glossary

Back to Part I: Choosing & Using an SCA

© 2000 - Cool Profit$ Magazine


A base of ethylene glycol or propylene glycol that contains chemical additives to prevent corrosion, foaming and other damage to the cooling system components. It must be mixed with water before it is used! The most common mixture is 50% each.




Their URLs


A&I Products

Accu-Tech Epoxy

Active Radiator



All Radiator Suply

Amer Honeycomb

American LokRing

Autom Air Group

Autom Air Intl

D D & E RadCap

Ecar, Inc.

Gano Filters

Genera Corp

Heatex Radiator

Heat Exhc Inc


Koyo Cooling Systems

Magill's Quality

Maine Auto Rad

NE Plastic Tanks

Old Air Products




Reco Heat Exch

Refrigerants Inc

Serck Services

Taalman Products

Tanks A Lot

Tanks N Tabs

Technl Trans Sys

The Radshop Suply

Therm Processes

ThermaSys Heat



Site Index


American Society for Testing of Materials (www.astm.org). This is the most important standards-setting organization in the world. They publish the specifications most commonly cited, ASTM D-3306 for cars, and ASTM D-6210 (new) and ASTM D-4985 (old) for trucks.


A chemical used in some antifreezes and SCAs to maintain the pH of coolant as it ages. It is a pH buffer.


In orange coolant, such as GM DEXCOOL®, some of the anti rust inhibitors are from this chemical family. Carboxylates are organic acids that have the chemical fragment COOH in the molecule.


To charge or pre-charge a heavy-duty coolant is to add 3% SCA to a 50% low silicate ASTM 4985 specification antifreeze and 50% water mix. In water 5% SCA is usually the pre-charge dose.


The fluid in the cooling system, usually half antifreeze and half water.

Coolant Filter

A filter through which the coolant flows. These filters are widely used as delivery devices for SCA chemicals. Care is necessary to insure the proper size filter, containing the proper chemical dose, is being used.

DI Water

Water purified by deionization. It is chemically pure, and contains no calcium or magnesium (hardness) found in many tap waters. It is preferred as the make-up for coolant, especially extended service coolants.


A chemical family found in some recycled antifreezes. These chemicals quickly deplete the inhibitor package, acidify the coolant and cause catastrophic cooling system failure in remarkably short periods of time.

Ethylene Glycol

The most common antifreeze base. At 50% in water, EG antifreezes provide freeze protection to –34 degrees F. The drawback to EG is that it is very poisonous.

Freeze point

By a specific ASTM test, the point where the coolant freezes. In reality, most coolants "slush," they don’t freeze hard like ice, and the freeze point is a conservative estimate of protection.

Fully formulated

This term describes the new heavy-duty coolants that contain all of chemicals necessary to protect diesel as well as car systems. The ASTM specification for fully formulated coolant, ASTM D-6210, requires simultaneous compliance with all of the previous automotive and heavy-duty specifications. Therefore, this is a true universal antifreeze specification and may be used in any system.


In the Fleetguard DCA-4 SCA and coolant technology, a component to prevent cylinder liner cavitation.


A general anti-corrosion additive that is especially effective in preventing rust (iron and steel corrosion).


Another additive present in all good SCAs and fully formulated antifreezes (ASTM spec D-6210) that is the most important additive for preventing cylinder liner cavitation.

Organic acid

A large family of chemicals usually used to refer in antifreeze discussions to carboxylate inhibitors.


The level of acidity (low pH) or alkalinity (high pH) of a liquid. In coolant, higher pH (9.0 to 11.0) is generally preferred. If the pH drops below 8.5 the formula may become unstable, and/or corrosion may occur.


A pH buffer used in the vast majority of coolants. It is effective and less expensive than borate, but less soluble. Detroit Diesel does not permit phosphated coolants.


A term to describe antifreeze that contains SCA. It is now obsolete; the term fully formulated is much better.

Propylene Glycol

An alternative, slightly more expensive antifreeze base. The best-known brand is Sierra®. It is much less toxic than ethylene glycol. Provides great corrosion protection, but slightly compromised freeze point.

Reserve alkalinity

The ability of a coolant to resist aging as reflected by the amount of hydrochloric acid required to pull the pH down to 7.0 in an ASTM test. Phosphated coolants typically have an RA of 10, borate-buffered coolants about 7.


Supplemental coolant additive. A chemical package that is added to coolant either as a liquid, powder, or charge inside a filter to fortify the coolant’s anticorrosive and other desirable properties. SCAs that meet the ASTM SCA specification are strongly preferred.


By far, the best protection against aluminum corrosion. Unfortunately, silicate has limited solubility in coolant and is often associated with radiator plugging in poorly formulated coolants or SCAs.

Silicate stabilizer

A chemical used in the best coolants and SCAs to prevent silicate from falling out and causing problems. This is an expensive chemical, and the cheapest antifreezes and SCAs often omit it.

Total Dissolved Solids

The concentration of everything in the coolant except the water and glycol. TDS in excess of 3% are associated with premature water pump and radiator failures.

© 2000 - Cool Profit$ Magazine
9 Natalie Circle ¤ Petaluma, CA ¤ 94952-3281 ¤ USA
Voice & Fax: 800-883-8929, or, 707-769-8929