Radiator Sealant STP 300 ml bottle — STP Kølertætner 300 ml

STP Kølertætner 300 ml is a ready-to-use radiator sealant formulated for automotive cooling systems. The liquid product is intended to seal small leaks, hairline cracks and porosities in radiators, heater cores and cooling system hoses without the need to disassemble components. Compatible with both petrol and diesel engines, this 300 ml bottle provides a compact solution for temporary sealing to reduce coolant loss and lower the risk of overheating while driving or during short-term repairs.

Advantages

The product is packaged in a 300 ml bottle for convenient handling and dosing. Its ready-to-use composition allows direct addition to the cooling system, eliminating preparation time. The sealant works on multiple cooling system elements including radiators, heater cores and some hoses, making it versatile for emergency and maintenance use. It is formulated for use in typical automotive cooling systems and designed to act quickly to reduce coolant leakage and associated temperature rise.

Suitable for

• Sealing small leaks in radiators and heater cores
• Temporary repair of porous cooling system hoses
• Use in petrol and diesel passenger cars
• Short-term prevention of coolant loss and overheating

Key specifications

• Volume: 300 ml
• Form: ready-to-use liquid
• Application: automotive cooling systems (radiator, heater core, hoses)
• Compatibility: petrol and diesel engines
• Function: seals small leaks and porosities without disassembly

How to use

Ensure the engine is cool before opening the cooling system. Shake the bottle if indicated on the label and add the specified amount of sealant directly into the radiator or expansion tank according to the vehicle manufacturer’s instructions or the product label. Start the engine and allow it to reach normal operating temperature so the sealant can circulate and reach the leak. Monitor coolant level and temperature after application and top up with the appropriate coolant if necessary. For persistent or large leaks, consult a professional repair service.

Usage recommendations

Use as a temporary repair measure only; the product is intended to prevent coolant loss and overheating until permanent repair or replacement of damaged cooling system components can be performed. Follow vehicle manufacturer guidance regarding coolant type and maintenance intervals. Avoid overfilling and ensure proper disposal of any unused product or empty containers in accordance with local regulations.