ASE G1 Auto Maintenance and Light RepairBrakesHard

A vehicle experiences a sudden, complete loss of braking effectiveness while driving. The brake pedal goes straight to the floor with no resistance. There is a strong smell of burning fluid. What is the MOST likely cause of this catastrophic failure?

  1. AA seized caliper piston.
  2. BWarped brake rotors.
  3. CA ruptured brake hose.
  4. DA faulty brake booster.
Show answer & explanation

Correct answer: C. A ruptured brake hose.

A sudden, complete loss of braking with the pedal going to the floor and a burning fluid smell strongly indicates a massive hydraulic fluid leak. A ruptured brake hose would cause a rapid loss of fluid from one circuit, leading to complete pedal drop and the smell of hot, leaking fluid on exhaust components.

Why the other options are wrong

  • A. A seized caliper piston would cause a pull and potentially reduced braking on one wheel, but not a complete, sudden loss of pedal to the floor for the entire system.
  • B. Warped brake rotors cause pulsation and vibration, not a sudden, complete loss of braking effectiveness or a pedal that goes to the floor.
  • D. A faulty brake booster results in a hard pedal requiring excessive force, not a pedal that goes straight to the floor with no resistance.

Brake Hose Rupture

A ruptured brake hose causes a sudden, complete loss of hydraulic pressure in one circuit, leading to the brake pedal going to the floor and potentially a burning fluid smell.

  • Sudden pedal loss
  • Complete loss of pressure
  • Burning fluid smell possible

Memory trick: Pedal to the floor, burning smell, a ruptured hose casts its spell.

More Brakes questions