Expert Advice on Diesel Coolant Selection to Prevent Engine Damage

According to the US National Oceanic and Atmospheric Administration, the period January through May 2024 was the warmest recorded in its 175-year-long temperature history for the Northern Hemisphere. Given that trend, it’s reasonable to expect that there is a strong chance this year could beat 2023 as the warmest full year on record. With that in mind, a webinar conducted by a leading filtration product supplier recently highlighted the need for closer focus on ensuring proper choice and testing of coolant systems in heavy-duty offroad diesel engines to prevent damage and prolong service life. Industry estimates point towards roughly 40% of all problems in this engine sector as being related to cooling system issues.

Jay Stevenson, North American trainer leader for Atmus Filtration Technologies, formerly known as Cummins Filtration, outlined the basic building blocks of diesel coolant chemical composition and explained how to properly choose a coolant product and keep it working effectively.

A heavy-duty engine coolant consists of three main components:

Water – Acts as the base component due to its excellent heat conductivity. It’s crucial to use high-quality water to avoid issues like scaling, which can affect engine performance. Premix coolant is recommended to ensure water quality, though concentrated coolant is also available, provided users ensure their water source is appropriate.

Base – This component extends the boiling and freezing points of the coolant. The most common bases are ethylene glycol (EG) and propylene glycol (PG). EG is more cost-effective and offers better freeze protection but is toxic. PG is non-toxic, making it suitable for environments where spills need to be non-hazardous, although it is more expensive and less effective in extreme cold.

Additives – A specific additive package can vary between brands, but is key for chemical protection. Additives protect against problems like cavitation and erosion in water pumps and liner pitting in cylinder liners. These issues arise from vapor bubbles formed by pressure, which can damage metal surfaces if not properly protected by the coolant. Properly formulated coolants create a chemical barrier, preventing such damage. Coolant additives, similarly to those in engine oil, wear out over time and need replenishment from supplemental coolant additives (SCA), but it’s essential to test and add the correct SCA amount to avoid issues like silicate gelling, which occurs when there is excessive additive content in the coolant. This can clog engine components such as water filters and radiators. To avoid problems, it’s crucial to measure the right amount of additives and conduct proper testing.

Stevenson pointed out that coolant color is often discussed but shouldn’t be relied upon because colors aren’t standardized across the industry. Different brands may use various colors for similar products, potentially leading to incompatible mixtures if color is the only consideration. Overall, the color of the coolant is simply the result of a dye added to aid in identification and has no effect on its quality or performance.

To identify the right coolant, always check the label for industry and OEM specifications. For heavy-duty diesel engines, a coolant should meet the ASTM D6210 standard, indicating it provides necessary protection against issues such as liner pitting and scaling. Additionally, OEM specifications, such as Cummins CES 14603, ensure compatibility with specific engine models, accounting for differences in materials and operating temperatures. If unsure, consult the manufacturer for guidance on the appropriate coolant for your application.

When evaluating coolants, beware of certain red flags. Avoid coolants containing 2-ethyl hexanoic acid (2-EHA) as it can damage silicone components, leading to failures in hoses and gaskets.

Recycled coolants often present another risk, as they lack industry standards and may contain impurities, “effectively making them colored water,” according to Stevenson. These are usually offered at low prices and should be avoided unless sourced from a reputable recycler, in which case they likely won’t be significantly cheaper than new coolant.

Universal conventional coolants, adhering to outdated technology (ASTM D4985), require supplemental additives to be suitable for heavy-duty engines. These products, said Stevenson, might be misleadingly marketed as heavy-duty, but the fine print reveals they only provide light-duty protection without added additives. Always read labels thoroughly and avoid products that require additional steps for proper use.

Overall, coolant customers can choose between legacy-formula and higher-tech formula coolants for heavy-duty diesels:

Conventional coolants, also called Inorganic Additive Technology coolants, are generally used in non-extended life, low silicate-requirement applications, offer legacy technology, are typically green in color and are cheapest initially but rank highest in total cost of ownership due to shorter service lives and the need for frequent testing.

Extended Life coolants (ELC). These blend conventional and newer technologies and can offer significant advantages over conventional coolants. They are offered in three main types: OAT (Organic Additive Technology), LOAT (Lowbrid Organic Additive Technology) and HOAT (Hybrid Organic Additive Technology). ELCs provide better protection, longer service live and need less maintenance.

Stevenson emphasized the importance of testing coolants regularly. Conventional coolants should be tested at every oil drain or annually. Hybrid coolants need testing every 150,000 miles or annually, while OAT coolants should be tested every 300,000 miles or annually. Different types of test kits are available to check coolant health: Quick Check test strips, for example, measure sulfate, chloride, and pH levels to ensure proper coolant balance. Water Check test strips checking the hardness, pH, and chloride levels of water used for mixing coolants. Three-Way test strips measure freeze point, malate, and nitrite levels.

Another important testing device, a refractometer, measures the freeze point protection of coolants, ensuring they can protect the engine in extreme cold weather.

Epiroc Expands Program for Safer Equipment Design

Mining equipment supplier Epiroc is expanding its Live Work Elimination (LWE) activity as part of a larger effort to reach its worker health and safety sustainability targets by 2030. It recently noted that it has released several new products in its LWE portfolio; however, according to Epiroc management, the program’s scope extends beyond product offerings.

“The goal of our LWE program is to make sure that when people work on our equipment, they are not exposed to any energy that would put them in harm’s way and cause injury. Our product portfolio is part of this, but it’s also about change management and reinforcing the safety culture in our industry,” said Lori-Anne Fleming, Epiroc LWE program manager.

The company pointed to three key elements of its LWE product focus. The first is to prolong product life and reduce the frequency of risk exposure, which means less chance of encountering hazards. The second is remote diagnostic tools that reduce the potential for injury. Third, constantly evolving technology offers new opportunities to remotely complete tasks that otherwise could expose people to potentially harmful energy. This is where automated solutions are key as are new developments in equipment design.

Epiroc said it had previously introduced some products that enhance safety while ensuring productivity. Among these are the Hydraulic Operated Bit Basket System (HOBBS) for the Pit Viper 270 blasthole drill line. This solution “takes away the need of having an operator working under a suspended load, a rotary head, while changing a drill bit on the deck,” explained Kajol Singh, global product manager LWE, who also noted that the company now offers HOBBS for its DML line of surface drills.

The latest additions to the LWE portfolio are a Boom isolation kit and a Spool Valve guard kit. They are both available as retrofit kits. The Boom isolation kit for Direct Control System (DCS) rigs isolates feed, boom, and rock drill functions without impacting operational cycle time. A machine can continue to run on electrical or diesel engine mode while all boom functions are isolated. The kit, said Singh, “makes it safer for an operator to enter the drilling area for maintenance work.”

The Spool Valve guard kit, designed for blasthole drill rigs, helps to lock out the 2, 7, 8, and 11 spool valve manual actuation points and reduces risk exposure for personnel working on the machine.