If the radiator hose in your car develops a tear or leak, it can initiate a chain of events that ends with your car overheating and your engine being exposed to damage. This can sometimes happen while you're on the road, and you'll have to try to drive your car to a repair shop. If this happens to you, you can still get several more miles out of your torn hose, but only if you think ahead and toss a roll of duct tape in the trunk.
Open the hood of the car if it is not already open, and identify the source of the leak. Sometimes you will be able to see steam spouting out of a tear in a radiator hose, and you may also see water or a combination of water and antifreeze leaking out.
Dampen an old rag if you have one handy and wipe the torn section of the hose clean. This is important because you will be patching the hose with duct tape, and duct tape doesn't always adhere well to dirty or dusty surfaces.
Use a dry portion of the rag to dry the hose thoroughly.
Tear off a long piece of duct tape and wrap it tightly around the torn section of hose. The tighter and smoother you can get the duct tape, the better.
Loosen the radiator cap all the way, then tighten it only part of the way. This takes some of the pressure out of the radiator system, making it less likely that you will blow your duct tape patch apart. You shouldn't drive with this cap loosened for an extended amount of time, though.
Drive to a repair shop immediately to get the hose permanently patched or, preferably, replaced.
