How to Maintain Heavy Duty Cooling Systems

The cooling system is a vitally important, yet often overlooked, part of any heavy-duty engine system. All vehicles include a cooling system, with coolant hoses and a pump circulating coolant (also known as antifreeze) through the engine and the radiator at the front of the vehicle. This uses the outside air to cool the coolant, keeping your engines heat under control throughout use.

This is incredibly important for heavy duty machines, with estimates of up to 40% of total engine repair costs being the result of issues stemming from the cooling system issues. Keeping this system well maintained can save time and money on costly breakdowns and prevent engines from overheating. This guide will give an overview of how to check your coolant system is working as intended, as well as ways you can keep yours in good shape.

Warning Signs of Cooling System Issues

Rising Temperature Gauge

Often the first sign of issues with your cooling system is a rising temperature gauge or warning codes and alarms from the Engine management system  If you notice this during operation, you should stop the vehicle as soon as possible to stop the engine from overheating. From there, you can assess the cause of this problem.

Low Coolant Levels

You should regularly make sure to check all fluid levels in your heavy-duty equipment, including the coolant. If coolant is low, make sure to fill it to appropriate levels. If you notice coolant levels dropping more than they should, this could be the result of a leak or coolant being combusted inside the engine. To tell if it is the latter, look out for white smoke coming from your exhaust.


If you notice smoke coming from your engine or white smoke from your exhaust, you should stop immediately. These could be indications of serious damage, such as a blown gasket or coolant ingress into the cylinder bore. This will require replacement parts or an entirely new engine if the engine bore is allowed to fill with water and hydraulic.

How to Maintain Heavy Duty Engine Cooling Systems

As with all tips to maintain heavy duty equipment, the key is routine preventative maintenance, with frequency depending on the engine. Some general tips include:

Water Pump

Pumps should be replaced roughly every 15/20,000 hours depending on application. To check your water pump, be sure to look out for broken seals, bearings, or system contamination to determine whether it can be repaired or needs replacing. Also listen to your water pump, is its noisy?


Coolant levels should be checked often and refilled when necessary. Also be sure to check the coolant is free from contaminants which could damage your engine. Be sure to use heavy duty coolant, which is unique from standard antifreeze, with its ability to protect against pitting cavitation which can greatly damage the engine. Ensure the appropriate antifreeze mix is applied to the environment the machine is operating on.  For those engines that are operating in warmer climates and do not require antifreeze ensure the correct Coolant inhibitor is used. This will prevent  corrosion damage to the cooling system. 

Water Filters

Water filters filter the debris from the cooling system that naturally occur and from contaminated water being used in the engine. To extend the life of cooling system components ensure water filters are changed regularly.    

Cooling Fan

Visually inspect the cooling fan for damage. If you hear unusual noises, see a decrease in coolant levels, or the temperature increases, you should check the fan drive mechanism and replace as necessary.


Check fluid levels as well as concentration in the radiator. Make sure there are no leaks, and also inspect the quality of the radiator cap.

With over 25 years of experience, Jaytrac supply a wide range of high-quality replacement parts for heavy duty equipment from brands including Caterpillar, KomatsuPerkins, and more. For more information on our range of products, contact us today using our online enquiry form, call us on 01604 491 133 or email us at

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