StopLeak® Liquid Heavy Duty

Product Information

Fast-Acting, Permanent Seal for Cooling System Leaks Get back on the road with confidence using StopLeak® Liquid Heavy Duty. This powerful formula delivers a permanent seal for radiator and cooling system leaks, while also conditioning your system with built-in lubricants and rust inhibitors. It’s the fast, reliable fix your cooling system needs, without the cost of a major repair.


StopLeak® Liquid Heavy Duty

Fast-Acting, Permanent Seal
Seals leaks in radiators, heater cores, and cooling system components quickly and effectively.

Contains Water Pump Lubricants
Helps extend water pump life by lubricating seals and bearings during and after treatment.

Built-In Rust & Corrosion Inhibitors
Protects the entire cooling system from rust, scale, and corrosion to help prevent future leaks and wear.

No Draining or Flushing Required
Treats your system without the need for complicated procedures, tools, or mess.


Ideal For:

  • Emergency or preventative leak repair

  • Radiator, head gasket & heater core leaks

  • Protecting water pump and cooling components

  • Reducing corrosion in older vehicles

  • Keeping high-mileage systems sealed and lubricated


Why Choose StopLeak® Liquid Heavy Duty?

It’s the ultimate solution for drivers who need a fast, affordable, and long-lasting fix for cooling system leaks. With added protection and system conditioning, it does more than just seal—it protects your entire cooling system.

Order Now and stop leaks before they stop you, trust StopLeak® for a dependable seal and lasting protection.

Buy Now

Part No.SizePcs/Case
SL-62411 OZ/325mL24/CASE