Here are the most likely causes:
* Low Brake Fluid: This is the most common and easiest to check. Locate the brake fluid reservoir (usually a clear or translucent container) under the hood. If the fluid level is low, you have a leak somewhere in the brake system. Do not simply add fluid. Adding fluid will only temporarily mask the problem; the underlying leak needs to be found and repaired.
* Brake System Leak: A leak in any part of the brake lines, wheel cylinders, calipers, or master cylinder will cause the pedal to go to the floor. This requires professional diagnosis and repair.
* Master Cylinder Failure: The master cylinder is the pump that builds hydraulic pressure to actuate the brakes. A failed master cylinder will prevent the brakes from working properly. This also requires professional repair.
* Wheel Cylinder or Caliper Failure: These components push the brake pads against the rotors or drums. A leak or internal failure in a wheel cylinder or caliper will result in a spongy or low pedal.
* Brake Booster Failure: The brake booster assists in creating the necessary pressure for the brakes. A malfunctioning booster will result in a soft pedal and reduced braking power.
* Air in the Brake Lines: Air in the brake lines can compress, causing a soft pedal. This often happens after brake work or a fluid leak. Bleeding the brakes may resolve this, but underlying issues still need addressing.
What to do:
1. Do not drive the vehicle. Call a tow truck or have it towed to a qualified mechanic.
2. Check the brake fluid level. Only note the level; do not add fluid.
3. Describe the problem to a mechanic. Tell them about the pedal going to the floor and the brake light illuminating. This will help them diagnose the issue efficiently.
Ignoring this problem could lead to a serious accident. Have it professionally inspected and repaired immediately.
