Radiators are crucial to keeping your engine cool. They are equipped with very thin cooling fins that are easily damaged. If you see antifreeze on the floor of your garage, or see wisps of steam rising from your engine when you are idling at a stop sign, you probably have a small leak in your radiator. You don’t need to panic, small leaks are easy to fix.
Cooling System Sealer – The best way to stop a radiator leak is by using cooling system sealers. You can buy these small tubes of pellets or solutions at any auto parts store work, and the fix is permanent, if the leaks are not bad. Just pour a container into the radiator while your vehicle is running. Drive or idle the car for at least 10 minutes. The particles in the cooling system sealer will travel to the leak. When the particles are exposed to air, they swell up and seal the leak. If one tube does not stop the leak completely, put another bottle of sealant in the radiator. If it still does not stop the leak is too big and will have to be fixed by a mechanic.
Loose Clamps – Radiator clamps can come loose. If you can’t tell where the anti-freeze is coming from, or it looks like it’s coming from the fittings, try tightening the clamps with a Phillips screwdriver. Apply a moderate amount of pressure, but don’t strip the clamp. If you have to use excessive force to tighten the clamp, the clamp is tight enough. The source of your leak may be somewhere else.
Duct Tape – Often when you see a puddle of antifreeze under your vehicle you can’t tell where it is coming from. If the leak is coming from one of the radiator fittings after you have tightened the clamp, the leak could be in the rubber hose itself. Hoses have a tendency to spring leaks where the radiator clamp is located. To temporarily stop a leak in the hose, remove the radiator clamp and wrap duct tape around the hose. Cover the leak with several wraps of the tape. Put the clamp back on. Buy a new hose when you get to an auto parts store. You can drive the vehicle for about a week but after that, the hose should be replaced.
Black Pepper – One of the oldest remedies for small radiator leaks is black pepper. By adding one or two tablespoons of black pepper to your radiator, you can temporarily stop a small leak. The pepper works its way through the system. It lodges in the hole and then swells up, sealing off the leak. This should be thought of as an emergency fix. Have your radiator drained and repaired by a mechanic at the first opportunity.
Epoxy Glue – If your radiator is cool and you have a small pinhole leak on the exterior of the radiator, temporarily fix it with epoxy glue. Clean the area around the leak. Make sure it’s dry. Mix together the two compounds that form the epoxy and then apply a small amount of the epoxy over the hole. Let it dry for 24-hours before driving.