Best Practices

What You Need to Know about Machine Coolant

The fluid that runs continuously through the engine and radiator in order to absorb and release heat is the machine coolant and is a necessary component to keep the machine running efficiently. Heavy duty coolant also helps prevent the engine’s cooling system from freezing, and enables it to avoid corrosion, cavitation, and rust.

Coolant is crucial to the health and productivity of your equipment. We’ve put together some tips and best practices to ensure the coolant is doing its job correctly.

Different types of machine coolant

There are several different types of heavy duty coolant that are used in construction equipment. The most common three are OAT, HOAT, and IAT.

Inspect heavy equipment battery electrolyte levels

Organic Acid Technology (OAT)/ Extended Life Coolant (ELC) —This type of machine coolant uses organic additives and typically has the longest intervals between changes.

Hybrid Organic Acid Technology (HOAT) — HOAT coolant includes a combination of organic and inorganic additives. This type of heavy duty coolant may require the use of a Supplemental Coolant Additive (SCA) or extender.

Inorganic Additive Technology (IAT) — IAT coolant uses inorganic additives and generally requires more maintenance and needs to be changed more often than the other two types. IAT coolants require the use of a Supplemental Coolant Additive (SCA).

Which type of heavy duty coolant should you choose?

To determine the right machine coolant for your diesel heavy equipment, make sure it is labeled as D6210 or RP329 by the American Society for Testing and Materials (ASTM). These numbers indicate that the solution contains the right supplemental coolant additive required by diesel engines. These coolants may also include nitrate to protect the iron and steel components in your cooling system, tolyl triazole to protect copper and brass parts, borate or phosphate to protect against acids, and silicate to help maintain aluminum components.

Don’t mix different coolants

It’s important that you pick a machine coolant type, avoid mixing it with other types, and follow the maintenance recommendations suggested for that coolant. If you are unable to use the same product to top off your coolant, then choose a product that is a similar type to the one already in your engine (OAT with OAT, IAT with IAT, etc.)

Machine coolant maintenance tips

It is important to understand the requirements of your heavy duty coolant and to inspect and test it about every six months. Failure to complete these inspections on schedule could result in expensive repairs and downtime for your equipment. Below are some guidelines for these inspections.

  • Periodic visual test to check the color—the coolant should be clear, indicating that no rust is present, and the color should match its original color, indicating that it has not been mixed with another type of coolant.
  • Test additive concentrations with a coolant analysis test by taking a sample and submitting it for analysis. The recommended interval for testing is 1,000 hours. Miller-Bradford & Risberg has easy to use sample kits available.

If you have any questions about machine coolant, contact the Miller-Bradford team today!