Brakes

Brake pedal goes to the floor

A brake pedal that sinks all the way to the floor with little resistance is a serious hydraulic failure, usually a major fluid leak or a failed master cylinder, and can mean a loss of braking ability.

Difficulty
Professional only
Time
1–3 hours for repair
DIY cost
$0
Pro cost
$200–$700

Symptoms

  • Pedal sinks close to or all the way to the floor
  • Braking feels weak or delayed, or doesn't work at all
  • Possible visible fluid leak under the car or near a wheel

Likely causes

  • CommonSevere brake fluid leakA ruptured line, hose, or caliper seal can dump fluid quickly.
  • CommonFailed master cylinderInternal seals wear out and let fluid bypass instead of building pressure.
  • PossibleAir in the brake system from an unresolved leakCombines with the leak's fluid loss to worsen pedal feel.
  • Less commonCompletely worn-through brake pads with no material leftExtreme neglect can let the pedal travel much further than normal.

What to do

  1. Pump the brake pedal several times; on some vehicles this can temporarily build enough pressure to slow down safely.
  2. Downshift to a lower gear to use engine braking to help slow the car.
  3. Use the parking brake gradually and carefully as a backup if the main brakes fail completely, being ready for the car to pull to one side.
  4. Get the car to a complete stop in the safest way possible and turn on hazard lights.
  5. Do not drive the car again until the brake system is repaired.
  6. Have the car towed rather than driven, even a short distance, if the pedal goes to the floor.
  7. Have a mechanic find and repair the leak or master cylinder, then bleed the entire system.

Tools and parts

Master cylinder (if failed)Search: “master cylinder for your car make and model”
Brake fluid, DOT rating from owner's manualSearch: “DOT 3 or DOT 4 brake fluid for your car”

When to call a pro

Call for a tow rather than driving the car, even briefly; this is a safety-critical failure that needs immediate professional repair.

Safety

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.