Nulon Radiator Stop Leak (R50) is formulated to effectively seal leaks in radiator and heater cores, weeping cylinder head gaskets and to temporarily repair corroded welsh plugs.

Nulon R50 is formulated with a base of fibre materials. Safe for seals and hoses, has no effect on metals, including aluminium, and is safe to use in all radiators. R50 is compatible with all corrosion inhibitor and all other anti-freeze/anti-boil products.

Note: 

• If the cooling system is dirty or restricted, first clean it with Nulon R40 Radiator Cleaner. 

Direction for Use:

Note: Exercise Caution when removing radiator cap if engine is hot.

1. Before adding this product, fill coolant to above top radiator hose
2. Start engine and turn heater on
3. Run engine until normal operating temperature is achieved
4. Shake bottle well & add slowly to radiator
5. Top up coolant & refit radiator cap securely
6. Run engine for 15 minutes to allow product to circulate
7. Inspect for leaks

Application Rates:

• Add 1 bottle for every 10 litres of water (or part thereof).
• To protect cooling systems against corrosion and electrolysis, use Nulon R45 Ultra Cool Concentrated Radiator Treatment or one of Nulon's Long Life Coolants.

Caution:

• Radiator stop leak products should only be used as a temporary repair.
• A qualified mechanic should check and properly repair the issue at the earliest opportunity.

Warning:

• When a cooling system overheats and boils, internal scale and sludge may become dislodged.
• This debris can block the radiator core, even if it was previously working well.
• Blockages may occur the next time the engine is run.
• If blockage is suspected, the radiator should be professionally removed and cleaned.

Part number: R50