Radiator Treatment

We offer a comprehensive range of products to ensure long-lasting radiator performance for locomotives. Our Mainline series of products are corrosion inhibitors designed for cooling systems on diesel engines. Additionally, we offer radiator flushes and nitrite test kits to support proper cooling system maintenance.

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Protect Cooling Systems from the Inside Out

In the railroad industry, overheating isn’t just inconvenient—it’s expensive. Corrosion, scale buildup, and cavitation damage can take entire locomotives offline. Temple Engineering radiator treatments are formulated to protect cooling systems on diesel engines from the inside, delivering long-lasting corrosion resistance, improved heat transfer, and reduced maintenance demands. Whether you're flushing out old systems or maintaining new ones, our solutions keep your engines cool and compliant.

Temple engineering Radiator Treatments

Advanced Cooling System Protection for Locomotive Engines

  • Mainline 101 Granular

    Mainline 101 Granular is a Borate/Nitrite based corrosion inhibitor specifically engineered for cooling systems on diesel engines. Mainline 101 is a complete inhibitor package containing Borate and Nitrite to passivate hard metals, along with a blend of organics and silicates to protect soft metals such as brass from corrosion. It uses an Enviroclear dye package, which turns clear when exposed to the environment or when the inhibitor package has become ineffective – providing a visual indicator of performance status. Mainline 101 is packaged in 2.5 lb bags, and should be added at a rate of at least one bag to every 50 gallons.

  • Mainline 101 WSB

    Mainline 101 WSB is a granular Borate/Nitrate based corrosion inhibitor specifically engineered for closed-loop diesel engines. Mainline 101 WSB is a complete inhibitor package containing Borate and Nitrate to passivate hard metals and a blend of organics and silicates to prevent the corrosion of soft metals including brass. It is packaged in a bag of film specifically designed to prevent breakage while still dissolving quickly in coolant.

  • Mainline 102

    Mainline 102 is a Borate/Nitrite based corrosion inhibitor solution specifically engineered for cooling systems on diesel engines. Mainline 102 is a complete inhibitor package containing Borate and Nitrite to passivate hard metals and a blend of organics and silicates to prevent the corrosion of soft metals including brass. Mainline 102 is a liquid solution that meets OEM specifications at a dilution rate of 1:64.

  • Mainline 137

    Mainline 137 is a Borate/Nitrite based corrosion inhibitor solution specifically engineered for cooling systems on diesel engines. Mainline 137 is a complete inhibitor package containing Borate and Nitrite to passivate hard metals and a blend of organics and silicates to prevent the corrosion of soft metals including brass. Mainline 137 is a liquid solution that meets OEM specifications at a dilution rate of 1:150.

  • Nitrite Test Kits

    Nitrite is most often used as a corrosion inhibitor, making it critical in various closed systems. Our nitrite test kits include the CAN test method. The CAN method is a popular option because it’s easier to run and supports systems with and without glycol.


    Please contact us for more information about Nitrite Test Kits.

Formulated for Compatibility and Compliance

Temple Engineering’s radiator treatment solutions are compatible with all major coolant types, including glycol and water-based systems. Our Borate/Nitrite based corrosion inhibitors are designed to passivate both hard and soft metals—protecting steel, aluminum, copper, and brass components in diesel locomotive cooling systems.

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Compatibility across mixed-metal systems

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Reliable pH stabilization and dissolved solids control

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Reduced risk of foaming, leaks, and underperformance

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Simplify compliance with FRA and OEM standards

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Built-in Visual Performance Indicators

Temple Engineering’s Mainline 101 corrosion inhibitor includes Enviroclear™ dye—a visual indicator that fades when exposed to air or when the treatment has lost effectiveness. This built-in signal helps your team monitor coolant health without invasive testing or lab delays, providing an extra layer of protection for your locomotive cooling water treatment program. It’s just one of the many ways we engineer our products to work smarter and safer in real-world rail operations.

Not Sure Which Radiator Treatment Fits Your Fleet?  Request a Product Match.

Tell us about your coolant system setup, metal types, or maintenance challenges, and we’ll guide you to the right treatment plan. We can also help integrate leak detection and testing protocols into your maintenance routine.

Radiator Treatment FAQs

  • Are Temple Engineering's Radiator Treatment products compatible with all locomotive coolants?

    Yes. Our radiator inhibitors are compatible with major water-based and glycol-based coolants and designed to stabilize pH, reduce foaming, and protect a wide range of metals.

  • What’s the benefit of the Enviroclear™ dye?

    Enviroclear™ fades when exposed to air or when the inhibitor is no longer effective—providing a visual signal that it’s time to service or replace your treatment.

  • How often should I flush and re-treat my system?

    We recommend reviewing treatment levels quarterly and flushing at intervals based on coolant condition, engine hours, and OEM guidance. Our 1108 Radiator Flush helps reset systems safely and effectively.

  • Do you offer testing kits or support with monitoring?

    Yes. We supply nitrite test kits and can help you implement a basic coolant monitoring program to ensure ongoing system health and corrosion control.

  • Can I order these in bulk or as part of a system-wide plan?

    Absolutely. We offer bulk shipment, recurring supply programs, and treatment plans tailored to your fleet’s size and needs.

Extend Engine Life with Smarter Cooling Protection

Don’t let corrosion, cavitation, or chemical imbalance sideline your locomotives. Temple Engineering’s radiator treatments are engineered to help your engines run cooler, longer, and more efficiently—backed by 20+ years of rail-focused chemical expertise.