How to Maintain Your Coolant System

How to Maintain Your Coolant System

Engines are incredible producers of heat and friction – the constant pressure and movement of innumerable metal parts rubbing against each other dictates that your engine will require a coolant system to help deal with this heat and friction – the eternal nemesis of the internal combustion engine.

The coolant system in your vehicle – unless you’re driving and old German air-cooled car – consists of a few parts that will inevitably require maintenance. This system works to efficiently combat heat in the engine – when it must work overtime, those parts are put under stress.

In this post, we’ll explain how to maintain your vehicle’s coolant system to help reduce the likelihood of more all-encompassing problems, engine overheating, and even potential seizure of integral parts.


Basic Function

Your engine’s coolant system is made up of a myriad of parts that all need to be in tip-top shape to help eliminate heat in your engine. Most people may be aware of their cars radiator, fan, and water pump – but what most people don’t realize is that a modern coolant system is also comprised of thermostats. Sensors, overflow tanks, water and coolant supply, numerous belts, clamps, and hoses.

In short, the system works by passing cool liquid past the cylinder heads and valves, commonly the hottest parts of the engine. The liquids are then directed back to the radiator where all of that collected heat is eliminated by the cooler interior temperature of the radiator itself. This routine loop then starts over again, using the same fluid to cool the engine over and over again.

The liquid itself is a combination of water and ethylene glycol – a green liquid that elongates and maximizes the boiling and freezing points of water. This mixture of coolant fluid and water is typically kept at a 50/50 ratio. In cooler climates like a Canadian winter, its common practice to boost the coolant level to abut 70/30.



Modern radiators, water pumps, and fans are intricate systems that – just like brakes, for example – will need maintenance as time progresses. Even simple components like belts and hoses can wear out over time, prompting replacement measures. So what can go wrong with your coolant system? We’ll break it down into some common part-based issues that can be easily maintained.



Hoses and belts snap and leak as they’re used. Simple as that. Maintaining your coolant system hoses and belts is often the most cost-effective and proactive way to minimize potentially huge repair bills. Hoses and belts are essentially the connectors that allow your coolant system to operate; without them, it doesn’t work, and you run the risk of an overheat.

Consumer Reports tells us that these flexible rubber components are the weakest points in the system, due to the fluctuation of hot and cold, as well as dirt and road grime deteriorating them over time. To maintain your hoses, squeeze the coolant hoses when the engine is cool. A hose that’s in good shape should feel firm, but pliable – with no soft spots. Take this opportunity to check both belts and hoses for cracks, nicks, bulges, and collapsed sections. You can also visually inspect the connection point to the radiator for fraying, cracking, or loose connections that can contribute to a leak when under pressure.

Electrochemical degradation (ECD) is arguably the most damaging to hoses, and manifests by way of cracking from the inside from the acids and chemicals in the coolant liquid itself. Eventually holes form from the disintegration of rubber, leading to leaks and ruptures. ECD can be minimized by routinely changing the coolant fluids – clean fluid is much less likely to contribute to ECD.

As a general rule, all hoses and belts should be replaced about every four years.



A coolant temperature sensor (ECT) is responsible for regulating the flow of coolant fluid into the hot parts of your engine, so a faulty sensor directly contributes to overheating issues. This sensor operates by knowing two things: the temperature of engine coolant, and the temperature of outside temperatures – you may find that your car has issues starting in the morning while the ‘check engine light’ isn’t on – this can mean that you have a faulty sensor that’s miscalculating the proper air/fuel mixture.

These sensors are vastly inexpensive (about $15-$25) and are easy to replace. Usually, ECTs are located near the front of the engine block and is commonly noted for its exposed terminal. The single wire leading into the terminal needs to be removed first, by prying the sensor clips away and pulling the lead wire out. Sensors are installed and removed much like spark plugs, using a wrench or socket. Always be sure to clean away the area with a clean shop rag to ensure a good fit.



A happy and healthy radiator is always full of liquid – so the easiest way to maintain the health of your radiator – the distributing force of coolant in your engine – is to keep it topped up with good, clean coolant. When you have your engine oil changed, or administer a winter maintenance package, ensure that your coolant levels are checked for quantity and quality.

Second, radiators are designed to operate optimally under pressure, so always make sure that your radiator cap is tightly secured to the main body. Lastly, always have your radiator flushed and cleaned once per year. An annual radiator check up, as part of a larger tune up will inevitably prevent larger maintenance issues or large repair bills. Flushes help to rid your system of buildup, and clogging of coolant gunk.


Water Pump

The job of your water pump is to distribute the chilled coolant to the hoses that cool hot engine parts. The pump regulates the flow of coolant, and therefore is integral to the success of your entire coolant system. Poor flow means less coolant reaches the engine, and overheating will inevitably follow.

To maintain your water pump, routinely check for puddles of greenish coolant underneath your vehicle when it sits for a long period of time. Leaks can also develop around gaskets and vents in the pump that act as cooling agents, and maintain pressure. Unfortunately, replacing a water pump is not an easy task, and should always be done by a licensed professional mechanic, as water pumps are routinely found underneath the timing cover. The upside of a water pump replacement is, this is a great time for your mechanic to inspect and potentially replace hoses and belts.


Your vehicle’s coolant system is arguably just as important as the engine itself, because without a properly functioning coolant system, the engine would overheat, seize, and you’d be in need of an entire new engine. Maintenance of your coolant system is largely a visual experience, checking for cracked and broken hoses, leaks, and observing your temperature gauge is your best line of defense against coolant system failure – and don’t forget changing those fluids regularly!