How to Patch a Radiator Hose

Remove the radiator hose carefully from the cooling line. Be very careful, because not only is the system pressurized, the fluid is extremely hot and both liquid and steam will escape. Remove the radiator cap with a thick wad of rags covering the opening and cap, easing the cap off a little at a time.

Find the portion of the hose that is leaking. If the leak is at the end of the hose near the connection then cut a small piece off the end of the hose that contains the leak and replace the hose, tightening down on the hose clamp to hold it in place until you can reach a service station and buy a replacement hose.

Cut the hose in the middle if you have a hose repair kit with hose clamps and a hose coupling. The hole can be cut out and the coupling used to rejoin the pieces of hose. Then the clamps can be used to hold the pieces of hose in place. If you don't have a hose repair kit in the vehicle, one very quick and very short term fix is to use duct tape to patch the hose. Wrap the tape around the hose working from about 4 inches on one side of the hole to about 4 inches on the other side of the hole and make sure that you wrap it many times back and forth with a few extra wraps right over the hole site. This will not hold long but perhaps will hold until the next service station where a proper repair can be made.

Refill the radiator with water and some antifreeze following any of the above repairs and then replace the radiator cap. Now try to start the car and make your way to the nearest service station as quickly as possible.