Most Common Causes of Radiator Leaks

Radiator leaks can be some of the most frustrating issues to deal with when owning a vehicle. Constant coolant top-offs, an overheating engine, and the smell of burning coolant are all signs of a leak in your cooling system. 

Your car’s radiator takes the anti-freeze and disperses it over metal fins that release your engine’s heat and return the anti-freeze to a lower temperature as it takes in cool air. Without a radiator, your coolant would never be able to release the heat from the engine, and the heat in the engine would build up to dangerous levels. 

A similar thing happens when you have a leak in your radiator. As the cooling system loses fluid, it loses its ability to take in and then release the heat. This can cause major issues down the line, as the engine begins to overheat and transfer heat to the parts around it. 

With this excessive temperature, the metal of the engine can begin to warp and expand, and the rubber gaskets will begin to degrade rapidly. While not all radiator leaks will reach this point before you notice, leaving a leak to continue and spread only increases the chance of expensive repairs down the line. 

There are a variety of reasons that your radiator could start leaking, and there’s no surefire way to know why yours is. However, there are a few common issues that you should be aware of so you can avoid them.


4 Common Causes of Radiator Leaks


One of the most common causes of radiator leaks is rust. Sediment will naturally build up in your coolant as your engine runs, and this sediment will gradually oxidize and cause rust. Eventually, this oxidation can eat through your radiator and cause leaks. 

In this case, you might notice puddles of coolant directly under your radiator when parked. If you’re sure the leak is coming from a rusted spot of your radiator, a replacement would be your best option as rust is difficult to remove and repair properly. 

Over-filled Coolant

Your vehicle’s cooling system is highly pressurized, and already puts a certain amount of stress on the metal and rubber components. When excess coolant is added, the pressure in the system can become too high and cause leaks in the seal and connections of a radiator. 

When refilling coolant, making sure to add within the recommended amount is vital to ensuring the effectiveness and safety of your cooling system. 

Checking the level of your coolant consistently is a good way to know if there’s too much or too little in your system. Make sure when checking or refilling that the engine has had time to cool down, as the pressure when hot can cause it to explode when opening the radiator cap. 

Faulty Radiator Cap

As we stated before, the cooling system is heavily pressurized. This means that even the smallest gap or fault in connections can cause substantial leaks. One of the primary places these leaks occur is the radiator cap. 

If the connection of the cap isn’t airtight, whether due to it not being tightened down enough or due to a damaged cap, coolant can and will find a way to leak out. These leaks can be very minor, but also difficult to notice. 

Replacing your radiator cap is inexpensive and may save you a hassle in the future, so checking your cap is one of the first things you should do when diagnosing a coolant leak.

Prior Overheating

While it may be easy to assume that your overheating is due to a radiator leak, your radiator leak may actually be due to overheating. Similar to overfilled coolant, overheating will cause your coolant to pressurize more than what’s healthy for your system and can cause leaks to develop in the radiator.

So if you notice a leak from your radiator, checking the other parts of your cooling system may reveal the real cause.

How do I Avoid Leaks?

Because the causes are so varied, there’s no single way to avoid leaks from your radiator. However, there are a few steps you can take to minimize the risk of one. 

  • Ensure proper coolant level regularly
  • Check for visible rust or damage
  • Flush your cooling system occasionally 
  • Use the proper coolant for your vehicle

Radiator and Cooling Service at Becker Service Center

If you notice any of the above issues or have any other cooling problems, it may be in your best interest to bring your car to a professional.

Luckily, Becker Service Center in Naperville, IL is your resource for cooling system service! Our ASE-certified technicians will ensure your vehicle is leak free and ready for the road. Our friendly team will walk you through every step of the service process so you can leave our shop with confidence in your vehicle. 

So call or schedule an appointment online today! Our team looks forward to seeing you.