When the brake pedal sinks to the floor, your car cannot stop reliably. This is a serious safety problem, not something to put off. The cause is almost always a brake fluid leak, a failed master cylinder, or air trapped in the brake lines. Stop driving and arrange a tow.
A car with no brakes is dangerous - to you and everyone else on the road. Do not drive it, even a short distance. Call a tow truck. If you must move it across a parking lot, use the parking brake to control speed and never exceed walking pace.
Brakes work by pushing fluid through sealed lines. A leak anywhere - a rusted line, a failed wheel cylinder, a torn caliper seal - lets the pedal sink to the floor. Look for puddles or wet spots near the wheels and under the master cylinder.
Get a Full Diagnosis →The master cylinder is the pump behind the brake pedal that pushes fluid to the wheels. When the internal seals wear out, the pedal slowly sinks under steady pressure even though no fluid is leaking out.
Get a Full Diagnosis →Air bubbles compress under pressure, while brake fluid does not. Air in the lines feels like a soft, spongy pedal that sometimes goes to the floor. Usually happens after a recent brake job that was not bled properly.
Get a Full Diagnosis →On older cars with drum brakes, the wheel cylinder can leak internally. On disc brakes, a torn caliper piston seal does the same thing. You may see fluid running down the inside of the wheel.
Get a Full Diagnosis →Tell us what you felt and what you see under the hood - we will tell you whether it is the master cylinder, a leak, or air in the lines, and what shops typically charge.
Get My AI Repair Report →$5.99 - covers your specific car, your symptoms, and the most likely fix with parts and price ranges.
No. This is one of the most dangerous things you can do in a car. Even if pumping the pedal seems to bring brakes back, the system can fail completely the next time you need to stop. Have it towed.
A master cylinder replacement is typically $300-600 at a shop. A brake line repair runs $150-400. A full brake bleed to remove air is $80-150. Replacing a leaking caliper or wheel cylinder is usually $200-500 per wheel.
This is the classic sign of a failing master cylinder. Internal seals are letting fluid bypass instead of holding pressure. The fix is replacing the master cylinder.
A sudden loss of pedal almost always means a brake line burst, a hose failed, or a major fluid leak started. Check the brake fluid reservoir immediately - if it is empty, do not drive.