How To Repair A Radiator Leak? (7 Simple Steps)

Want to know how to repair a radiator leak yourself? We've got you covered!

In this ProperMechanic.com guide, you'll learn:

  • How to tell if you should hire a pro or DIY
  • The typical price ranges for DIY radiator repairs
  • ​Supplies you'll need to fix your radiator leak

And much more!

How to Repair a Radiator Leak

Repairing a leaking radiator isn't a small task, but you can certainly do it on your own with a little time and knowledge. 

The radiator is a heat exchanger that usually sits in front of the motor.

And, the water pump is constantly pumping coolant through it. 

When the vehicle’s coolant goes through the radiator pipes the heat energy is dispersed and transferred to the pipes and fins of the radiator. 

You may discover that your radiator is leaking antifreeze. It could even be from a pinhole size that you might not ever see physically with your eyes. 

Which is exactly why we created this guide to help you learn how to repair the leak on your own!

So, if you're looking for a permanent solution, here's how you can approach fixing your car's radiator leak yourself (and whether or not to consult a professional)!

What You Need To Know About Repairing A Radiator Leak

We've all heard stories of car overheating problems. Stopping to refill the coolant reservoir might get you off the road, but a temporary fix isn't going to solve the problem.

You are going to need a permanent repair. In most cases replacing the radiator is the only option.

Coolant leaks don't always come from the radiator. Spraying the engine off with water will help you more easily locate the leak.

Note: Always be sure to drain the coolant first before switching the radiator out. When doing so unscrew the radiator cap to allow the coolant to flow freely downwards.

This will make the whole process easier and keep you less messy. Be sure to dispose of your coolant properly.

Some radiator repairs can be a little pricier for the part. This is where shopping online can be a lifesaver. When looking to fix your leaky radiator yourself, $200 might look a lot better than paying a mechanic double.

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Should You Hire or DIY To Repair a Radiator Leak Repair?

If you are not an experienced mechanic, then you should hire a professional to perform the repair for you. 

But it also depends on your skill level and also the complexity of the repair. Some radiators like newer Volkswagens, for example, require much more than just a screwdriver. 

If you are stranded on the side of the road, you are going to have to either tow the vehicle or wait until the car's cooling system gets cool enough so that you can pull off the road safely.

What Are The Price Ranges for DIY Radiator Replacement Jobs?

We've all heard stories of car overheating problems. Stopping to refill the coolant reservoir might get you off the road, but a temporary fix isn't going to solve the problem.

You are going to need a permanent repair. So the question is: should you do it yourself or hire a professional?

Low-End Cost: $50

If you are an ambitious car repairman then why not head to your local auto parts store and replace the radiator yourself when it breaks?

That’s a great idea. If you are really in a pinch you can go to a junkyard and pull a radiator out of a wrecked car that has the same radiator as yours; doing so will teach you how to get to your radiator before you perform the repair.

Just take into consideration that you will also be sacrificing your time to save the money. 

Average Cost: $200

Some radiator repairs can be a little pricier for the part.

This is where going to the junkyard can be a lifesaver. When looking to fix your leaky radiator yourself $200 might look a lot better than paying a mechanic double. 

High-End Cost: $500

If you are going for high-performance or drive a super expensive car then you could end up purchasing a radiator that costs a bit more.

You can always get some information by talking to a parts department that is dedicated to your vehicle's brand.

Did you know: The typical radiator leak costs about $400 to repair if you take your car to a professional.  That's why learning to fix it yourself is so important!

What Are The Price Ranges for Professional Radiator Replacement?

A shop or mechanic is going to charge you anywhere from 2-4 service hours to repair or replace your radiator.

Every shop charges a different rate per hour, so hopefully, you can find a reasonable price on your radiator fix if you are not willing to perform the work yourself. 

Low-End Cost: $300

Finding someone to fix your radiator for cheap shouldn’t be too hard. And if your vehicle isn’t worth very much or has an easily accessible radiator then it’s okay to hire out the work for cheap.

Just make sure that the business you hire has good reviews on google so that you don’t get ripped off or left with a bad repair. 

Average Cost: $600

If you are in the average price range then the repair could go either way; do it yourself or hire out the work to a professional. Use your best judgment. 

High-End Cost: $1200

If you drive an expensive car you are asking for expensive auto repairs. The radiator is no different. And the labor will be more expensive too because it will require more labor hours to replace.

You should rely on a professional to perform the work on your high-end vehicle to protect yourself from losing money on an improper repair.

Besides, if you drive an expensive car you should be able to afford to let someone do the dirty work for you. 

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Supplies You’ll Need For Repairing A Radiator Leak 

Here are some supplies and tools you'll need to fix your radiator leak:

  • Flathead screwdriver
  • New coolant
  • Catch basin/container to drain the coolant into
  • Flashlight
  • Safety goggles/glasses 
  • Pliers/channel locks
  • Basic socket and wrench set
  • Nitrile gloves (optional)
  • Mechanic's pick

(Note: Always be sure to drain the coolant first before switching the radiator out. When doing so unscrew the radiator cap to allow the coolant to flow freely downwards. This will make the whole process easier and keep you less messy. Be sure to dispose of your coolant properly.)

How to Repair a Radiator Leak in 7 Simple Steps

It's always worth the money you are going to save from taking your vehicle to a shop.

Think about it; the hundreds of dollars you spent on having someone else perform a repair for you could have been spent on more tools for your collection.

When you see coolant coming out of your closed system, the first step is to spray the engine off with water to verify the location of the leak.

After you have discovered that the leak really is coming from the radiator and not one of its hoses or a bad seal on the radiator cap, here are some simple steps to follow when repairing a radiator leak:

  1. Let the vehicle cool off

  2. Remove the radiator cap and drain the coolant

  3. Remove radiator hoses/radiator mounts(possibly the bumper)

  4. Remove radiator and compare it with the replacement radiator

  5. Replace with new radiator, connect hoses and mounts

  6. Fill with the correct coolant

  7. Test drive for verification of successful repair

Step 1: Let the vehicle cool off

You can't touch coolant when it's hot; it will burn you. Sit back and relax for however long it takes for the engine to cool off.

When you see coolant coming out of your closed system, the first step is to spray the engine off with water to verify the location of the leak. 

After you have discovered that the leak really is coming from the radiator and not one of its hoses or a bad seal on the radiator cap, here are some simple steps to follow when repairing a radiator leak.

Step 2: Remove the radiator cap and drain the coolant

Have you ever put your finger or tongue on the top of straw after sucking on it? The liquid stays in the straw. 

It's the same with your coolant. You have to unscrew the cap on the top to allow the liquid to flow out of the engine.

Step 3: Remove radiator hoses/radiator mounts and all electrical connectors necessary(possibly the bumper)

The difficulty of removing your radiator depends on the vehicle you are working on.

Every vehicle has its own set of instructions for removing the radiator. If you aren't sure, find the set of instructions for your vehicle, and follow them exactly.

Radiator hoses come loose by removing the fastener, twisting, and pulling on the hose. 

An easy way to remove some radiator hoses is by sticking a flathead screwdriver/mechanic's pick in between the hose and radiator fitting and separating them from each other.

You could also try grabbing the end of the hose firmly with channel locks and twisting it.

Step 4: Remove radiator and compare it with the replacement radiator

You can't replace the radiator with a new one that isn't compatible. The first way to avoid buying the wrong radiator is by plugging in your vehicle's VIN into Amazon or auto parts store website before purchasing. 

Step 5: Replace with new radiator, connect hoses and mounts

Reconnect everything exactly how it was. Taking pictures and notes of the procedure beforehand always helps to remember everything you have removed.

Step 6: Refill with the correct coolant. Start the vehicle and inspect.

Fill up your coolant reservoir to the top. It's time to see if you have successfully fixed the problem. After you have everything in place, start the engine and inspect it and the ground for signs of leakage. 

Step 7: Run the engine until the coolant level goes down. Top off the coolant

The engine has many nooks and crannies that hold coolant inside. Most times when refilling the coolant the first time it doesn't do the job. You have to run the engine, and let the existing coolant run down through the system.

The thermostat will eventually open, sending coolant through the engine. You may also get a low coolant warning again, but don't let it worry you if there is no coolant on the ground; top it off and enjoy a functioning vehicle!

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Repairing Your Coolant System Yourself: Is It Worth It?

If you need a radiator repair then you are already being inconvenienced.

The important decision when repairing your radiator yourself or hiring someone to perform the repair is deciding which is going to be a more effective method for you.

For someone who has access to all the tools, it may not be necessary to take the car to the shop, but if you are broken down on the road far away from home it’s almost always necessary to tow your vehicle to a workshop to have the work done by a professional close by.

About Your Mechanic

About Ryan Nichols

Ryan here! My pro mechanic career began as a technician for Mercedes-Benz. After two years of that great experience, I went out on my own in both the automotive and construction fields. I've since pulled my share of salvage yard parts and fixed more vehicles than I can count.

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