Do I Need to Drain the Old Windshield Washer Fluid When Replacing It?

[VonJonathan]

Replacing windshield washer fluid does not require draining the old fluid. Unlike antifreeze, mixing different windshield washer fluids is not a problem. The amount of fluid added is crucial—adding too much is not only wasteful but can also cause engine components to rust. When refilling, do not exceed the MAX mark and always leave some space. Windshield washer fluid forms a monomolecular protective layer on the glass surface, preventing fogging and ensuring clear visibility. Its higher viscosity also provides lubrication, reducing friction between the wipers and the glass to prevent scratches.