Radiator leaks happen. If your radiator starts leaking, it does not mean you have taken poor care of your vehicle. This is just a natural part of a car’s aging process. That being said, radiator leaks can be dangerous. If your car is low on coolant, your engine can overheat, and causing hundreds of dollars of damage, and in some cases, a couple thousand dollars of damage. This can completely be avoided, though, and you can fix a radiator leak on your own for just a few dollars!
Find the location of the leak. Use the garden hose to wash down the radiator and the hoses. Then, start the engine and look for the leak.
Replace a hose if you find that the hose is what is leaking. Simply remove the old hose and reattach a new one. Check again for leaks to make sure you have successfully fixed the leaky radiator.
Fix leaks on the actual radiator with a cold weld epoxy. To do this, drain the radiator, clean the leaky area, and apply the cold weld epoxy.
Seal the epoxy by moving the overflow line to a vacuum port on the engine's intake manifold. Take off the distributor cap and turn the engine over a few times. This will create a slight vacuum that will seal the epoxy into the cracked part of your radiator.
Fix leaks on the radiator tube by pulling the cooling fins away from the tube using your pliers. Cut the tubing. Pull the cut ends up so that they touch themselves. This will resemble the end of a tube of toothpaste. Crimp these ends together and apply the cold weld epoxy.
Allow the cold weld epoxy to cure for two hours before refilling the radiator.
Refill the radiator and get ready to drive the car again!