Can you fix the mistake of putting engine oil in brake fluid?

Do not drive your car if you have put engine oil in the brake fluid reservoir. Brake fluid is designed to be compatible with the rubber seals and components in your braking system, while engine oil is not. Engine oil can damage these seals and cause your brakes to fail.

To fix the mistake, you will need to:

1. Remove all of the engine oil from the brake fluid reservoir.

2. Inspect the brake fluid reservoir and lines for damage.

3. Replace any damaged components.

4. Flush the brake fluid system with fresh brake fluid. This can be done independently, but due to the safety-critical nature of the braking system it is recommended to visit a mechanic.

5. Test the brakes to make sure they are working properly before driving your car again.

If you are not comfortable performing these steps, you should take your car to a qualified mechanic.