Engines are the heart of all modern heavy equipment. By combusting fuel, engines produce tremendous power, allowing machines to perform incredible feats of strength with ease.

During the combustion process, a machine’s engine produces a large amount of heat. If not managed properly, the excess heat generated in the engine may cause it to perform inefficiently, leading to a host of malfunctions and causing the engine to break down.

Cooling systems are designed to help maintain the engine at a constant temperature, preventing the engine from becoming too hot. Most heavy equipment uses a liquid-based cooling system, which cools the engine by circulating coolant through the engine block.

As coolant absorbs heat in the engine block, it is cycled out of the engine and into the radiator. In the radiator, coolant is forced through an array of narrow, gilled tubes, which efficiently dissipates excess heat from the coolant.

To facilitate the exchange of coolant between the engine and radiator, a host of components like fans, fan drives, thermostats and valves must work in tandem. Collectively, these components help maintain the engine at the ideal temperature, preventing it from running too cool or too hot.

In this guide, we’ll cover the ins and outs of maintaining heavy equipment cooling systems. By keeping your machine’s cooling system in good operating condition, you can help extend the life of its engine and avoid costly repairs.

Common Signs Your Cooling System is Experiencing Issues

When your machine’s cooling system malfunctions, engine troubles lie just around the corner. Without a properly functioning cooling system, the engine is bound to overheat, leading to a host of performance issues.

By recognizing the signs of a failing cooling system early on, you can avoid costly breakdowns and damage to your machine’s engine. Here are some warning signs to look out for.

1. Overheating. The most obvious sign your machine’s cooling system is malfunctioning is overheating. This is typically accompanied by a warning light or message on your machine’s dash. Common reasons for this malfunction are a broken thermostat, blocked radiator, low coolant levels, a malfunctioning water pump or air pockets in the coolant.
2. Vapor or Smoke. Another sign of a broken cooling system is steam or smoke coming from the engine compartment, often accompanied by a strong odor. This is typically caused by a leak in the cooling system, causing coolant to leak onto hot engine components.
3. Reduced Power. When your machine struggles to perform at its usual capacity, a malfunctioning cooling system may be to blame. Insufficient coolant circulation, airlocks in the cooling system, or a malfunctioning water pump can lead to overheating, which can hinder engine performance.
4. Rapid Coolant Loss. One symptom of a faulty cooling system is rapid coolant loss, requiring you to top up your machine’s coolant more frequently than usual. The most common causes of rapid coolant loss are corrosion, physical damage or faulty seals within the cooling system.
5. Visible Coolant Puddles. Puddles of coolant underneath the equipment after it has been parked indicate a problem with the cooling system. Exposure to debris, harsh conditions or improper maintenance can lead to physical damage or wear on the cooling system components, causing leaks.
6. Gurgling or Boiling Noises. Unusual noises like gurgling or boiling may indicate a problem with the cooling system. These noises are caused by air pockets formed in the coolant, a condition known as airlock. Airlock can be caused by inadequate bleeding of the cooling system during maintenance, coolant leaks or improper coolant mixture.

If your machine is exhibiting any of the issues above, stop operation and have it serviced. Continuing to operate heavy equipment with a malfunctioning or broken cooling system can have serious and potentially catastrophic consequences for the equipment itself and its engine.

Cooling System Maintenance in Heavy Equipment

When it comes to maintaining your machine’s cooling system, a strategy of preventive maintenance is preferred to one of reactive maintenance. By maintaining your machine’s cooling system according to a well-defined schedule, you can make sure maintenance tasks don’t slip through the cracks.

Here are some important maintenance tasks that should form the basis of your cooling system maintenance plan.

1. Maintain Proper Coolant Levels

An essential task of cooling system maintenance is maintaining proper coolant levels. Low coolant levels can result in a drop in performance and engine overheating. Older cooling systems typically require a mixture of distilled water and antifreeze, while newer systems require a specific liquid coolant.

To find the type of coolant required by your machine’s cooling system, consult the service manual. Check the coolant levels often, and replenish the coolant as needed.

2. Inspect the Radiator Fan Frequently

As the radiator releases heat into the surrounding environment, the air around the radiator becomes hot. The radiator fan has the important task of keeping fresh air circulating around the radiator, cooling it down and facilitating the dissipation of heat around the radiator.

If the fan blades become stuck, bent, chipped or damaged, the radiator will have a diminished ability to cool down the engine, leading to performance issues. To keep the radiator fan working properly, inspect it once per week, making sure to address any issues immediately.

3. Replace Coolant According to Manufacturer Guidelines

In addition to removing excess heat from the cooling system, coolant also plays a role in preventing corrosion inside the radiator and the cooling jacket of the engine block. Over time, coolant becomes less effective at both of these tasks, making your cooling system less effective and more prone to corrosion.

To prevent avoidable damage to your machine’s cooling system, it’s important to replace the coolant regularly. For best results, consult your machine’s service manual and replace the coolant according to the intervals set by the manufacturer.

4. Keep the Radiator Clean

Due to their high surface area, radiators are incredibly efficient at dissipating heat to the outside environment. However, if the radiator becomes covered in dust, mud or other debris, its ability to transfer heat to the surrounding air may become greatly hampered.

Begin each shift by inspecting the radiator and clearing away any mud or debris that may hinder its performance.

5. Inspect Hoses, Seals and Fittings

One common cause for coolant leaks is worn seals, hoses and fittings. As hoses, seals and fittings become corroded, cracked or worn, they may lose their ability to keep the cooling system sealed off.

To prevent coolant leaks, check the system’s hoses, seals and fittings regularly, keeping them clear of dirt and debris. Pay special attention to cracked hoses and corroded fittings, and replace them as soon as possible.

6. Coolant Analysis

While maintaining proper coolant levels is critical to the performance of your cooling system, it isn’t always enough. Coolant analysis is a type of test that can reveal impurities in your coolant, problems with its admixture or other indicators of a failing cooling system.

To get the full benefits of coolant analysis, perform this test at the beginning of each summer and winter.

Final thoughts

Cooling systems are intricate, yet vital parts of all modern heavy equipment. Without efficient cooling systems, the capabilities of our machines would be greatly reduced. Keeping your machine’s cooling system in good working order will help its engine operate smoothly and efficiently.

The MechLink Shop is a useful tool for operators and fleet managers looking to purchase OEM and aftermarket parts for heavy-duty engine cooling systems–such as radiator hoses, coolant filters, fans, pumps and more. Can’t find the part you’re looking for? Reach out to our parts experts to place a custom order.