How to Repair a Hole in a Radiator

If you see a car broken down on the side of the road, chances are that something is wrong with the radiator, leading to a malfunctioning coolant system. The good news is that many radiator holes can be fixed, at least temporarily. This should give you enough time to safely drive the car to a mechanic who can do more extensive and lasting repairs.

Instructions

1

Locate the hole in the radiator. Turn the engine off and let it cool until it is safe to touch. Open the hood and pour water over the radiator and hoses to clean off any dirt, grime or coolant that is present. Turn the engine on and look for areas where the green coolant fluid is visible on the outside of the radiator. In many cases the leak is on a seam of the radiator.

2

Drain the radiator completely according to the instructions in your vehicle's owner's manual. Catch the radiator fluid in any available container like a bowl, empty water bottle or plastic tub. Use shop towels or rags to wipe up any visible fluid on the container and under the vehicle.

3

Wipe down the outside of the radiator with a clean shop towel or rag.

4

Apply the cold weld epoxy to the area where the hole was found, using the instructions on the package.

5

Draw the cold weld product into the crack. Use your manual to identify the various parts of your radiator system. Move the overflow hose to the intake manifold and attach it to the vacuum port. Take the distributor cap off. Turn the engine over several times so that the vacuum will suck the cold weld deep into the hole in the radiator. Return all the parts to the proper setup.

6

Cure the cold weld product for at least two hours before driving the vehicle.

7

Refill the radiator with the recommended mixture of water and coolant.