How to Repair a Radiator Leak

While none of us want to suffer from a radiator leak (they suck, trust us, because we hear all the horror stories from customers), it’s important to know the signs and take action to avoid a major coolant leak before it happens.

At the first sign of coolant leaking from your radiator, you should avoid driving your vehicle and take steps to stop the leak. As experts with over 70 years of experience in vehicle fluid system repair and treatment, our engineering and technical support teams want to point out the signs of a radiator leak and give you tips on how to repair it.

How Does a Radiator Leak Develop?

A radiator leak can occur in several locations:

  • In the radiator itself: Corrosion or damage to the core of the radiator can allow coolant to leak out. If the leak is moderate to major, you may need to replace your radiator. Leaks aren’t an on/off switch – they are on a continuum, which means there are literally thousands of types of leak severity.
  • In the hoses or lines: Holes or cracks in the rubber coolant hoses in your engine and cooling system can allow coolant to leak. Age is a big factor here: these hoses get brittle over time and start to crack.
  • At hose connection points: If your hose clamps work loose or break, pressurized coolant can seep out. If your radiator hoses get loose enough, they can pop off entirely, creating a major coolant leak.

If you detect any of these radiator leaks, make sure your engine and coolant are cool before attempting to make any repairs. The coolant in your engine is pressurized when hot and can cause serious burns. In some cases, you may need to tighten the hose clamps or replace them if they are rusted. Split or weeping hoses should be replaced, taking care to avoid tight bends that might block coolant flow.

What Are the Colors of a Radiator Leak?

The coolant in most older vehicles is green, while some modern vehicles may have coolant that is orange, pink or blue. Coolant should be handled with care, as it is poisonous to humans and animals if ingested and can harm the environment and waterways. If you see a fluid of any color leaking from your vehicle, it is important to determine where it is coming from and stop the leak.

Keep Your Coolant Clean

Fresh, clean coolant can help keep your vehicle cooler and reduces corrosion in your radiator. Inhibitors in your coolant break down over time, and the water in your coolant mixture can corrode copper and aluminum radiators and create a leak. Follow your manufacturer’s suggestion for replacing your coolant on newer vehicles, changing it at least every 30,000 miles or five years, whichever comes first. Plus, getting a flush is like a detox for your cooling system – you change your oil, and coolant is no different. You just change it at a longer time interval.

Other Solutions for a Coolant Leak

Some leaks in your radiator and cooling lines can be hard to access. That’s why here at Bar’s Leaks, we’ve been perfecting the formulation of our radiator stop-leak products for nearly 100 years. Browse our entire line of cooling system repair products and find the radiator stop leak treatment that suits your type and severity of leak. We are the brand leader in chemical repair tools, and we’ve progressed the science of these products more than any other company on earth. We’ve been around the block a few times.

You can use our handy online locator to find an outlet near you. We also invite you to contact our helpful and knowledgeable team if you have any questions or need help choosing the right radiator stop-leak product for your coolant leak. We talk to customers every day on the phone and via social media, so if you have a question, don’t hesitate to ask. We’re happy to help.

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