What is the purpose of "flushing the brakes"?

Flushing the brakes is primarily conducted to remove moisture contamination and old fluid. Over time, brake fluid can absorb moisture from the air, which can lead to reduced boiling points and compromised performance. The presence of moisture in the brake fluid can result in corrosion within the brake system components and may create a safety hazard, particularly in terms of brake performance.

By thoroughly flushing the brake system, the old fluid, which may be contaminated and less effective, is replaced with fresh, clean brake fluid. This helps maintain optimal braking performance, ensuring that the fluid has the proper properties to handle heat and maintain pressure without vapor lock.

Maintaining the integrity and effectiveness of the brake fluid is crucial for overall vehicle safety and performance, making this procedure an important maintenance task for vehicle owners.