Wynn’s Radiator Stop Leak

Code: 55864

Wynn’s Radiator Stop Leak is a sealing product to stop small leaks in the cooling system, with anti-corrosive properties.

  • Stops and prevents leakages in the radiator, cooling and heating system.
  • Stops head gasket leaks.
  • Will not harm rubber hoses, gaskets or other system components.
  • Is compatible with all antifreezes and coolants, also with OAT coolants (Organic Acid Technology).
  • Is formulated to avoid clogging of radiator waterways and temperature sensors.
  • Enhanced protection against rust and corrosion.


In Stock


Recommended for all “water” cooled systems of petrol, LPG and diesel engines when minor leaks are noted.
Can also be used as preventive agent.

Warm up the engine with heater control in HOT position.
Shake bottle well and add contents to the cooling system via the expansion tank if part of the system circuit (2 hoses: out and return) or directly into the radiator if a single hose overflow tank is fitted.
Top up the system with coolant if required.
Run engine for approximately 5 minutes to circulate and stop leaks.
Contents treat a cooling system from 5 to 12 litres.
If the coolant is dirty, flush system with Wynn’s Radiator Flush and refill with new coolant before treatment with Radiator Stop Leak.

Additional information