How To Stop a Leak in a Plastic Radiator

Plastic radiators have increased in popularity since the last decade of the 20th century. Some auto manufacturers employ all plastic radiators, while others employ radiators constructed of plastic and aluminum. As an alternative to traditional brass radiators, plastic is lighter, more efficient and easier to repair when a leak occurs. The material is different, but the job performed is the same---keeping the engine from overheating by circulating coolant through the engine and by radiating heat away from the vehicle. When a radiator acquires a leak, the material does not matter---the radiator will need to be repaired to avoid bigger and more expensive problems.

Instructions

1

Visually observe the underside of the vehicle and under the hood to identify any leaks. Search for leak sources that may give a clue to their origination. A leaking hose, for example, may still have moisture from a coolant leak even after the car has been turned off. Alternatively, fire up the engine and after giving it time to warm up, look for leaks in the cooling system that may spew or drip. It is especially important to check the storage tank of a plastic radiator, since storage tanks are more prone to leaks in this type of radiator. Once you've discovered the source of the leak, you can plan the method of repair.

2

Disconnect both ends of the leaking hose using a screwdriver on the metal rings that hold the hose at each end. Remove any debris that may remain on the opening before attaching the new radiator hose. Connect the new radiator hose to both openings and secure the metal rings to both ends.

3

Remove the plastic radiator from the vehicle after all the coolant has been drained. Using an air-free plastic welder, heat the radiator in the location of the leak and place heat on the welding rod to melt it over the leak.

A general purpose epoxy may be used to repair a leak in the body of a plastic radiator. Prep the leak area with sandpaper and apply the epoxy, allowing it to set before reinstalling the radiator in the vehicle.

4

Pour a can or bottle of coolant system sealant, nearly universally recognized as "Stop Leak," directly in a cooled radiator. Add coolant or water to fill the radiator and drive the vehicle for 30 minutes or more to flush the coolant system sealant throughout the radiator and coolant system.