How to Stop an Instant Leak in a Radiator

A leak can occur in a radiator in an instant. A car's cooling system is pressurized and the pressure can cause an old, worn rubber hose to pop open and spill coolant out of the cooling system. That pressure can also cause seams in a plastic radiator that are already weak from stress to open. Rocks, dirt and other debris from the road can fly into the radiator and cause punctures. An instant leak in the radiator can instantly cause the radiator to malfunction and allow the engine's temperature to rise to damaging levels. An instant leak must also be repaired quickly, in order to prevent damage to the engine or the car's cooling system.

Instructions

1

Stop the vehicle before too much coolant leaks from the vehicle after an instant leak is noticed. Pop the hood and examine the radiator to determine the location of the leak. Inspect the seams of the radiator, as well as the surfaces, hose connectors and radiator cap. Alternatively, conduct a pressure test of the radiator if the instant leak cannot be identified readily. Cleaning the surface of the radiator with air or water will reveal most leaks.

2

Replace the leaking part connected to the radiator, including upper and lower hoses or the radiator cap. Hoses and the radiator cap can cause the radiator to leak coolant quickly, if they develop a malfunction. Hoses can rip or tear and the rubber seal on the radiator cap can become warped. A new part should be used, even if it appears that the hose can be taped. Such a temporary fix will not last long and the hose will need to be replaced.

3

Weld (either with solder for brass radiators, or epoxy for plastic radiators) the broken piece or open seam of the radiator once it has cooled off. Epoxy can also be used for brass or plastic to seal punctures on the surface of the radiator. Allow time for either welding method to set.

4

Pour a container of cooling system coolant into a radiator with an instant leak, especially in cases where the leak is so small that it cannot easily be identified. Drive the vehicle for the recommended time ---usually thirty minutes --- to allow the sealant to work its way through the radiator and fill in the instant leak.

5

Refill the cooling system and radiator after repairing the instant leak. Visually inspect the radiator while the car is running to determine if the repair has worked.