What to Do If Windshield Washer Fluid Is Added to the Brake Fluid by Mistake?
2 Answers
If you accidentally add windshield washer fluid to the brake fluid while topping up, you must not continue to use it and should immediately take your car to a professional repair shop to replace the brake fluid. Anything related to the braking system is critical and must be handled with caution. Here is some relevant information: 1. Windshield washer fluid is a cleaning solution used to wash the car's windshield. When adding it, you need to open the hood, locate the washer fluid reservoir, and pour the fluid into it. 2. The function of brake fluid is to transmit the pressure from the master cylinder to the wheel cylinders. Since the wheel cylinders are directly connected to the brake pads, the high temperatures generated during braking are also transferred to the brake fluid. Once the brake fluid reaches its boiling point due to high temperatures, bubbles form, which can impair the transmission of braking force, leading to a spongy brake pedal or, in the worst case, complete brake failure. Therefore, brake fluid must have a high boiling point. 3. If windshield washer fluid is mixed into the brake fluid, even without a chemical reaction, it will dilute the brake fluid and lower its boiling point. Moreover, a chemical reaction could cause the brake fluid to deteriorate completely. 4. There are various types of fluids used in cars, including engine oil, automatic transmission fluid, manual transmission fluid, brake fluid, coolant, power steering fluid, windshield washer fluid, etc. Each fluid has a different function and must not be mixed. The only exception is that some cars use the same fluid for power steering and automatic transmission.
This situation is really troublesome. As a car enthusiast, I must say: mixing windshield washer fluid and brake fluid is absolutely not okay! The brake system relies on fluid to transmit force, while windshield washer fluid contains alcohol and detergents. Mixing them can cause chemical reactions, corroding the brake lines or clogging the pipes, leading to brake failure. Step one: immediately avoid starting the engine or pressing the brake pedal—it's too risky. Step two: call a tow truck to take the car to a reliable repair shop. The technician will need to drain the entire brake system, thoroughly flush the pipes and ABS components, and replace all the brake fluid with new stuff. The whole process is time-consuming and expensive, probably costing a few hundred to a couple thousand bucks. But for safety, it's worth it! Don’t try to fix it yourself—without professional tools, you might mess up even more. When refueling, I always remind myself to check the labels and not mix up the caps.
