Wynns Cylinder Block Seal (72250)

• Forms a glass hard layer when exposed to air.
• Repairs cracks in cylinder blocks of cast iron, steel and aluminium, without dismantling.
• Stops small leaks/cracks in metal head gaskets.
• Assures a permanent repair in 30 minutes.
• Resists high pressures, water pressure and vibration.
• Does not clog hoses.
• Does not repair rubber gaskets.

• Normal treatment

Replace old liquid by water. Add Wynn’s Cooling System Flush to the water. Let the engine run for 15 min. Drain this mixture and rinse with water. Refill system with water. Remove the upper radiator hose and the thermostat. Shake the bottle of Wynn’s Cylinder Block Seal before use. In cold temperatures, warm the bottle. Pour Wynn’s Cylinder Block Seal into the opening of the removed thermostat (325 ml treats circuits up to 8 litres). Replace the dismantled parts to close cooling system again (thermostat is NOT replaced). Top up liquid level with water. Warm up engine. After warm-up let the engine run for at least 15 to 20 minutes. Check water temperature during treatment. Stop the engine. Drain when engine is cold and flush completely. Fill with cooling liquid (antifreeze + water). Replace thermostat

• Cracks in cylinder wall

Proceed in the same way, but remove the spark plug (petrol) or injector (diesel) from the damaged cylinder. When several cylinders are damaged, remove the spark plugs (injectors) sequentially, leaving each one out for 5 minutes. 

• For large cracks

Proceed in the same way, but leave Wynn’s Cylinder Block Seal in the cooling system for 3 to 4 days, before draining.

• If the product is spilled on glass or paint, remove immediately with clean water.
• Use Wynn’s Cooling System Stop Leak to prevent and stop leaks in the radiator.