Radiator Repair: How to Repair a Car Radiator Leak

What You'll Need
Epoxy Gun
Engine Coolant
Garden Hose

Radiator repair is something that car owners should make themselves aware of. The radiator is a vital part of any vehicle, as it helps to keep it cool. Your car must be kept cool so that it can function as it should. A car that has a leaky radiator is something that you should look out for, as it can become a very expensive problem. The sooner that you are able to fix your vehicle’s radiator problems, the better off it will be.

Step 1: Find the Leak

The first step to fix this problem is to find the leak. You must first allow the radiator to cool, or you also have the option to wash it down with water, which will be much faster. After you have washed the car down, and smoke no longer billows from the radiator, you can then restart the car and look for the leak. Locate the leak to ensure that it is actually the radiator and not another part, such as a hose. If the problem is a leaky hose, you should replace the hose entirely without attempting to patch it. 

Step 2: Begin the Patch

Take your radiator epoxy, or cold weld epoxy, and have it ready for use. Once you have identified the location of the leak, you will need to drain the radiator. After your radiator has been drained, clean the area around the leak being careful to make sure that you don’t make the leak any bigger, and apply the epoxy. Once you have the epoxy in place, you must then establish a vacuum in the radiator.

Step 3: Vacuum Seal

After your epoxy is in place, you will then take the overflow hose and place it in the vacuum port of your car’s manifold. You will then remove the distributor cap and crank the car three to five times. By cranking the car but not allowing it to fully turn over, you are creating a vacuum seal on your epoxy, which is pulling the epoxy into the crack in the radiator. 

Step 4: Check your Tubing

While you have your radiator drained, it is a good idea to check your radiator tubing as well. To do this, pull the tube away from the fins that cool the radiator. If you notice damage to the tubes, you can also use the epoxy to fix the radiator tubing as well. The epoxy will need anywhere from two to three hours to dry. Be sure to not do anything to the vehicle during this time, as heat or water can compromise the epoxy, and it will not adhere correctly. 

Step 5: Refill your Radiator

After you have allowed the epoxy a proper amount of time to dry, you are now ready to refill your radiator. This can be done one of two ways. One way to refill is to simply use a garden hose until you notice that water is not continuing to drain into the radiator. IF a garden hose is unavailable, use a funnel and bucket.