Why should you avoid using brake fluid from multiple sources?

Using brake fluid from multiple sources should be avoided primarily because different types may not be compatible. Brake fluids come in several classifications, such as DOT 3, DOT 4, DOT 5, and DOT 5.1, each with distinct chemical compositions and boiling points. Mixing these fluids can lead to undesirable chemical reactions, decreased performance, or even damage to the brake system components. For example, using silicone-based fluids with standard glycol-based fluids can result in brake fade and reduced braking efficiency. Ensuring compatibility helps maintain the integrity and functionality of the brake system, ensuring safe vehicle operation.