Will putting windshield washer fluid in antifreeze container do damage?

Yes, putting windshield washer fluid in the antifreeze container will likely cause damage. Windshield washer fluid is not formulated for the same purpose as antifreeze. It doesn't have the same properties to protect your engine from freezing or overheating, and the different chemical compositions can lead to:

* Corrosion: Windshield washer fluid is often more corrosive than antifreeze, potentially damaging engine components.

* Damage to seals and gaskets: The different chemical makeup can degrade rubber seals and gaskets in your cooling system.

* Reduced cooling efficiency: It won't offer the same protection against freezing or overheating. This can lead to engine damage in extreme temperatures.

* Pump failure: The washer fluid may not lubricate the water pump effectively, leading to premature wear and failure.

In short, avoid mixing the two fluids at all costs. If you accidentally put some washer fluid in the antifreeze reservoir, you should have the system flushed and completely refilled with the correct antifreeze/coolant mixture.