Updated at: 17-04-2022 - By: micdot

One of the easiest ways to tell if your car radiator has leaked is when you always have low coolant levels or there’s a green radioactive puddle under your car. You might also like this post about some of the things I use to flush my radiators at home.

A lot of times, this can be hard to do, but fixing this problem can be very easy.

How To Fix A Radiator Leak With J-B Weld

Step 1- Empty the radiator:

Make sure your engine isn’t too hot, then let it cool down for a while.

Also, make sure that your battery is disconnected and that your engine is covered with a blanket to keep water from splashing.

You should remove the radiator cap to let air in, and then put your container below the radiator plug.

Take off the plug and let the fluid drain until it stops.

Step 2-  Wipe off the area where the leak is located:

Wipe off the area where the leak is, making sure to get all of it. The rust and other debris can still be scraped away, but make sure you clean up any grease, grime, or dirt with a rag and solvent.

Step 3 – Mixing the J-B WELD:

Make sure the black and red tubes (J-B WELD) on your disposable plastic surface are equal parts. You can now mix them with your wooden tool to make sure they are all mixed together. J-B WELD sets very quickly, so make sure you’re quick.

Step 4

Spread the mixed J-B WELD all over the area where the leak is with the wooden tool.

As soon as you finish making the mixture, it will harden in about 4 to 6 hours. It will be completely cured in 15 to 24 hours.

Step 5

Change the radiator plug that is on the bottom of the radiator. Then, refill the radiator fluid to the correct level.

Change the radiator cap and take the blanket off of the engine to make it run better. Now you can reconnect your battery and start your car.

Can You Put JB Weld On A Radiator?


You can, of course! As you know, a radiator is very hot, and most cars have about 15 pounds of pressure when they are running.

Also, it’s a plastic tank and radiator repair kit that can be used to make short-term or long-term fixes to both metal and plastic radiators.

Which JB Weld Is Best For Radiator Repair?

The J-B Weld 2120 Radiator and Plastic Repair Kit is for people who want to fix their radiator and other plastic parts.

The radiator stop leak in this package is very good and cheap. Users can use it to fix leaks in radiators with J-B weld’s product.

People who use this product can get a long-term fix if there are small cracks and leaks in their radiator.

The product also helps to keep the radiator safe from rust and corrosion, which helps to keep it safe.

These are the things:

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It will save you a lot of money because it is very cheap to fix.

Simple to use, quick, and it’s a long-term answer.

There are things in it to keep it from rusting and corroding, like wax.

A water lubricant comes with the machine when it’s bought.

One of the things people like about this product is that it’s cheap, which makes it a good choice for small radiator repairs.

This product will save you money and protect your engine parts for a long time to keep them from breaking down again.

How To Fix A Cracked Radiator Plastic

This is how to fix your radiator if there is a leak coming from it.

Step 1 – Find the Crack:

In case you didn’t know, one of the easiest ways to find a crack in the radiator is to let your engine run until it gets hot.

Make sure to keep in mind that it could take at least 30 minutes for the pressure to build up.

If your engine is still running, you should turn it off now. The pressure will force coolant from the crack.

Tape or a marker can now be used to make a mark on the cracked part of the surface. Let it cool down, then take off the cap.

Check to see if the crack is below or above the level of coolant. It might be below the coolant level. Drain some coolant until you see that the crack is above the level.

With a drain tank cylinder, make sure you drain the radiator tank before you do anything else. However, make sure you have a new bottle of coolant to use when you finish fixing the radiator’s crack.

Step 2 – Preparing the radiator crack area for repair:

Use a toothbrush to clean the crack and then dry it. You should put a little acetone on the toothbrush and start scrubbing the crack and the area around it with the toothbrush.

As long as you keep scrubbing, the area should be dry and there should be no more water on it after acetone has evaporated.

Then, hold a hairdryer near a crack to dry the area. Take note that moisture will return, but you should keep blowing the crack until it’s dry again. Clean and dry the area again.

Step 3 – Continue the repair:

Take a soldering iron and put it on the tie until it starts to melt. This will make a seal. Put and push the tie into the crack. Moving slowly around the cracked area, make sure the wax melts well enough to close the crack. To melt a part, keep doing it until the tie and its surroundings become a hot liquid.

As you wait for the liquid to harden, keep melting the whole crack until you have filled it all in with the liquid.

Now, cut off all the parts of the tie that aren’t used. It’s time to fill the radiator with coolant and run a test to make sure the crack isn’t still open.

With just a little knowledge and a little elbow grease, you have been able to fix your broken plastic radiator on your own by yourself.

How To Repair Plastic Radiator With Soldering Iron

This is what you need to do:

Drain the fluid from your radiator if it is leaking. The spot needs to be dry before you can do anything else with the radiator.

Then they clean the area where the grease is and get rid of it. If you want to clean something up, you can spray it with WD-40 or something like that.

Use a soldering iron to go along the leak and melt the plastic back together and make a new seal around it, then let it cool.

It is important to melt the plastic in a way that fits how big the crack is, so that it can be repaired.

Then you need to check to see if the plastic still leaks after you melt it. Is this the only way to find out if you’ve fixed it?