Brake pedal goes to the floor
A pedal that sinks to the floor with little or no braking means the hydraulic system has failed — stop driving.
What this usually means
This is the emergency version of a soft pedal. When the pedal travels all the way to the floor with weak or no braking, the hydraulic system has lost the ability to build pressure — almost always because fluid is escaping through a ruptured line or failed component, or because the master cylinder’s seals have given out internally. Most cars split the brakes into two hydraulic circuits so a single failure leaves partial braking, but “partial” means dramatically longer stops. This is one of the few car problems that is a genuine roadside emergency rather than a schedule-a-visit item.
Most likely causes
- highRuptured brake line or hoseA corroded steel line or a cracked flexible hose can burst under braking pressure, dumping fluid fast. Common on older cars in rust-belt climates — look for fresh fluid on the ground near a wheel or along the car’s underside.
- highMaster cylinder internal failureWhen the master cylinder’s seals fail completely, pedal effort bypasses the pistons instead of pressurizing the lines. The reservoir may still look full because the fluid isn’t leaving the system — it’s just not doing anything.
- mediumFailed caliper or wheel cylinder sealA blown seal at one wheel leaks fluid every time you press the pedal. You’ll often see a wet, oily film on the inside of one wheel or a puddle by a tire.
- mediumAir in the system after recent brake workIf the pedal went long right after a repair, the system may not have been bled properly. Still unsafe to drive — the fix is straightforward, but it needs to happen before the car moves again.
- lowSeverely worn pads or misadjusted rear brakesExtreme pad wear or badly out-of-adjustment drum brakes add pedal travel, though they usually announce themselves with noise and a gradually lengthening pedal first.
How urgent is it?
Typical fix & cost
The shop finds where the pressure is going: a burst line or hose is replaced and the system flushed and bled; a failed master cylinder is replaced as a unit; a leaking caliper or wheel cylinder is swapped along with fluid-soaked pads if the leak reached them. On older cars where one line rusted through, expect the recommendation to replace neighboring lines too — they corrode as a set.
Typical range: $150–$1,000
A single line, hose, or wheel cylinder is the low-to-middle range; a master cylinder or multiple corroded lines pushes the high end. Add a tow.
The price depends on which cause it turns out to be, so confirm the cause before paying. Diagnose this for my car →
Start a case with what you’re noticing. Redline weighs these causes against your car’s evidence and names the check that would settle it.
Common questions
Why does pumping the brake pedal bring pressure back?
Pumping temporarily moves enough fluid to build partial pressure before it escapes again through the leak or failed seals. It can help you stop the car once in an emergency — it is not a reason to keep driving.
Can I still stop the car if the pedal goes to the floor?
Most cars have two brake circuits, so a single failure usually leaves weak braking on two wheels, plus engine braking and the parking brake. Use all three to get safely to the shoulder, then call a tow — don’t test your luck in traffic.
Related symptoms
General guidance, not a substitute for a hands-on inspection. Cost ranges are broad reference ranges, not quotes. For safety-related issues, have the car inspected before driving.
Seeing this on your car?
Every problem becomes a Case. Tell Redline what the car is doing: it shows what the evidence supports, what’s still missing, and what to check next, before you approve a repair.
“Inner pad ~1 mm. Outer pad 3 mm.”
Next: check the slide pins move freely before buying parts.