I bought Steel Seal because our car was leaking cooling water and there was also negative pressure. About half a liter of water per day. Did everything according to the instructions. Even flushed the cooling circuit with 30 liters of water. Then filled a bottle of Steel Seal into the expansion tank with fresh water and let it run for 30 minutes after reaching operating temperature. Leave to cool overnight. The next morning, no water loss and no more vacuum. The engine runs smoothly again. Can really only recommend Steel Seal. Thanks for the super product! Torsten Franke 27.01.2023, 17367 Eggesin |