How Long Can a Radiator Leak Sealer Last?
2 Answers
Radiator leak sealer is a one-time use product, with one bottle being used per application. Typically, it can stop a leak within three minutes of application. After sealing the leak, do not drain the water, as the curing process takes 36 to 48 hours. Once cured, it can last for up to a year without leaking. Radiator leak sealer is effective to some extent, but it is not suitable for obvious leaks; it only works for minor seepage or slow leaks. If the radiator leak is severe, the radiator should be replaced. The sealer works by forming a membrane on the inner wall of the radiator, acting as a protective layer that patches the leaking points. However, prolonged use can lead to clogging of the radiator's pipes.
I've used radiator sealant a few times for emergency fixes. Generally, after purchase, the packaging will indicate an expiration date, usually 2 to 3 years, but don't just rely on that. In actual use, how long it can seal minor leaks depends on the leak size and driving conditions. For example, small cracks might hold for a week or two, but in hot weather or frequent highway driving, it might only last three to five days. Last time I used it in summer, it started leaking again the next day. The key point is this is a temporary solution—don't drag it out to save trouble. It's best to get to a repair shop ASAP to address the real issue. A leaking radiator affects engine cooling, and if it gets worse, it can damage the engine, costing way more than an early repair. Plus, overusing sealant can clog cooling fins, so it's really not a long-term fix. Regular maintenance checks on coolant levels can prevent problems beforehand.
