Purpose and Specifications

The LIQUI MOLY Radiator Stop-Leak is a premium 150ml additive that permanently seals small leaks in your vehicle's cooling system, such as those from stone impacts, porous solder joints, or hairline cracks. It protects the engine by preventing coolant from entering the combustion chamber, works safely with aluminum radiators, and is compatible with all conventional coolants and antifreezes.

One 150ml bottle treats up to 10 liters of coolant. Add it to a cold system, run the heater, and drive for at least 10 minutes to activate. It stays in the system indefinitely without clogging lines, pumps, or heaters, ensuring reliable cooling from -40°C to over 120°C operating temperatures.

• Volume: 150ml – perfect for most cars
• Shelf life: 3-5 years if stored frost-free
• Effect lasts: 100,000+ km or 4+ years with proper coolant maintenance

When to Use / Replace?

Use it when you notice dropping coolant levels without obvious puddles, or as preventive maintenance every 2 years / 40,000 km on older vehicles to stop leaks before they start. No need to replace – it remains effective permanently unless you flush the system during major service.

Ideal for quick roadside fixes; seals leaks immediately so you can drive home safely without overheating.

FAQ

Q: Is it safe for my aluminum radiator?
A: Yes, fully compatible and won't harm aluminum, plastic, or rubber parts in modern cooling systems.

Q: How long until I see results?
A: Leaks seal within minutes after reaching operating temperature; drive 10 minutes for full effect.

Q: Can I use it preventively?
A: Absolutely – add before leaks develop to protect against common cooling issues in high-mileage cars.