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Brake Pedal Goes to the Floor

Stop Driving

A brake pedal that goes to the floor is one of the most serious brake symptoms. Common causes include low brake fluid, a hydraulic leak, air in the brake lines, or a failing brake master cylinder. The vehicle may not stop normally, so this should be treated as a stop-driving problem until proven otherwise.

Stop driving — this can cause serious damage or be unsafe.

Check These First

Before diving into diagnosis, quickly verify these:

  • 1Check brake fluid level without driving the vehicle.
  • 2Look behind each wheel and under the car for wet brake fluid.
  • 3Press the brake pedal once and see if it slowly sinks under steady pressure.
  • 4Check whether the red brake warning light is on.

Most Likely Causes

Ranked from most to least common — start at the top.

1

Brake Fluid Leak

A brake fluid leak means hydraulic fluid is escaping from the brake system. Low fluid can cause a soft pedal, longer stopping distance, pulling, or total brake failure.

Stop DrivingDIY ModerateMost likely: Leaking caliper seal or piston boot →
2

Air in Brake Lines

Air in brake lines compresses under pedal pressure, making the brake pedal feel soft, spongy, or inconsistent. It usually enters after a leak, low fluid, or brake hydraulic service.

Fix SoonDIY ModerateMost likely: Recent brake repair without proper bleeding →
3

Failing Brake Master Cylinder

A failing brake master cylinder cannot maintain hydraulic pressure. It may cause a brake pedal that sinks, inconsistent braking, or loss of braking force without an obvious external leak.

Stop DrivingShop JobMost likely: Internal seal bypass →
4

Worn Brake Pads or Rotors

Worn brake pads or damaged rotors reduce braking performance and can cause grinding, squealing, vibration, and longer stopping distances.

Fix SoonDIY EasyMost likely: Pads worn to minimum thickness →

Related Symptoms in Brakes

Other problems to check if this isn't your issue.

Brake Noise and Squealing

Fix Soon

Brake Noise and Squealing needs a focused diagnosis because the same symptom can come from several different parts. Start with the checks that match when it happens, then verify the likely cause before replacing parts.

Brake Pedal Feel Diagnosis

Fix Soon

A hub for soft, spongy, sinking, hard, or low brake pedal symptoms.

Brake Pulling or Uneven Stopping

Fix Soon

Brake Pulling or Uneven Stopping needs a focused diagnosis because the same symptom can come from several different parts. Start with the checks that match when it happens, then verify the likely cause before replacing parts.

Brake Pulling or Uneven Stopping

Fix Soon

Use this hub for brake pull, uneven brake application, veering during braking, dragging brakes, and left/right brake imbalance.

Brake Vibration and Pulsation

Fix Soon

A hub for steering-wheel shimmy, brake pedal pulsation, and shake that shows up when braking.