Helpful Automotive Resources
How to Bleed BrakesOpening the hydraulic portion of the brake system introduces air into the brake lines. While air is compressible, brake fluid (like any other type of liquid) is not. Brake fluid that’s full of air reduces the force the hydraulic system creates, resulting in a dangerously spongy brake pedal.
A Short Course on BrakesWhen you step on the brake pedal, you are actually pushing against a plunger in the master cylinder, which forces hydraulic oil (brake fluid) through a series of tubes and hoses to the braking unit at each wheel. Since hydraulic fluid (or any fluid for that matter) cannot be compressed,