What happens if the brake fluid is low?

If the fluid get low enough air gets into the master cylinder. When this happens, the brake pedal will get soft or spongy when it is pushed. Braking performance is affected if air gets in the brake's hydraulic system. This is because the air, like any gas, can be compressed.

How does brake fluid get low?

  1. When brake pad wear, and brake system uses more fluid volume
  2. Fluid boils, getting bubbles in the line.
  3. Lines, master cylinder, or calipers leak

A little low is maintenance but too low is not and it needs some professional checks.