How to Repair a Leaking Automotive Radiator

An automotive radiator is an integral part of the car's cooling system necessary to keep the vehicle running properly. The system works by circulating radiator fluid to the engine block to keep it cool when running. A radiator leak may smell when the car is running and leave puddles of radiator fluid when the car is parked. Repairing a radiator depends on what part is leaking and what kind of radiator you have. Locate the source of the leak and repair accordingly.

Instructions

1

Fill your radiator to the appropriate level and start the car. Inspect the radiator and hoses closely to locate the source of the leak.

2

Drain the radiator by unscrewing the drain cock on the bottom and letting the fluid flow into an appropriate container. If it is a hose leak, proceed to Step 3. If there is a very small hole in the radiator, proceed to Step 4. If the radiator has a larger hole or crack, proceed to Step 5.

3

For hose leaks, remove the clamps holding the hose in place. Remove the hose by sliding it off the radiator outlet and the engine inlet. Replace the faulty hose with a new one by sliding it back over the inlet and outlets and securing into place with the hose clamps.

4

Repair the small radiator leak by adding a bottle of radiator stop leak to the radiator after the radiator is refilled with fluid.

5

For larger leaks, remove the radiator if necessary for easy access to the leak. Apply solder, epoxy or J-B Weld to the hole after thoroughly cleaning the surrounding area. Solder can go on radiators made from copper or brass, special plastic epoxy can be used on plastic ones and the J-B Weld can plug holes in aluminum radiators.

6

Attach the drain cock in place. Fill the radiator back to capacity and screw the cap back on. Inspect for leaks again.