Brake Pedal Goes to the Floor? Causes, Warning Signs & What to Do
Reviewed by Eric Shepherd, ASE-Certified Technician
Few things get a driver's attention faster than pressing the brake pedal and feeling it sink toward the floor. Millions of people call Phoenix and its surrounding cities home. At any given moment, there are thousands of people on the road across the Valley of the Sun. Any issue with the brake pedal, such as it feeling soft or going to the floor, usually means there is an issue with the hydraulic brake system.
Losing brake pressure can make it much harder, or potentially impossible, to stop safely in Valley freeway traffic. Not to alarm you, but it makes for pretty unsafe driving conditions. You don't want to tempt fate. If you experience a soft pedal, or one that feels non-existent, have your vehicle towed to the nearest repair shop and don't drive it until it's resolved.
Once you're at the repair shop, qualified technicians could diagnose something as simple as brake lines that need to be repaired because they are old and crusty, or something a little more intense like a hydraulic component within the brake system.
At Gemba Automotive, our technicians see brake issues every day and they know that the way the pedal feels can tell you a lot about what's going on and help narrow down the problem.
Here's what Arizona drivers should know:
Is It Safe to Drive if Your Brake Pedal Goes to the Floor?
The brake system in your vehicle uses hydraulic pressure to transfer the force from you pressing the brake pedal to the actual calipers that stop your car. If that pressure is lost or becomes compromised, in addition to a pedal that drops to the floor, it will take longer to stop, or you won't be able to stop at all, which creates unsafe driving conditions for you and those around you.
What Should You Do If It Happens While Driving?
If you're casually driving home from work and the pedal stops working, it is recommended to follow these steps:
- Keep calm and remain focused on the road ahead of you.
- Stop applying the gas—just coast and turn on your hazard lights.
- Avoid jerking the wheel or making sudden turns.
- Try pumping the brakes to rebuild some pressure.
- Use your parking/emergency brake to slowly stop the vehicle.
- Once you come to a complete stop, call a tow truck. Don't start driving again until the brake system has been professionally inspected.
What Causes a Brake Pedal to Go to the Floor?
There are several reasons why your car can have a soft brake pedal or spongy brakes.
Low Brake Fluid
Brake fluid works to create pressure in the hydraulic system. If, for some reason, the fluid level becomes too low, it could present itself as a soft brake pedal. Low fluid levels are typically the result of a leak somewhere in the system.
Brake Fluid Leaks
Not every leak will be large enough to leave a noticeable puddle on your driveway. Fluid can leak from the following places:
- Brake lines
- Flexible hoses
- Brake calipers
- Master cylinder
- Other various components
Air in the Brake Lines
If the brakes haven't been serviced correctly or the fluid reservoir becomes so low that it introduces air into the system, you can end up with a spongy or springy feeling pedal. Air can be compressed when it is in the system, so when you press on the brake, the air will be compressed rather than the brakes immediately being applied.
Failing Master Cylinder
Picture this: you're in the Starbucks drive-thru, foot on the brake, ordering a pumpkin spice latte and wishing for cooler weather when the pedal starts to slowly sink. A pedal that slowly sinks while you're applying consistent pressure may be a sign that the master cylinder is having an issue. The master cylinder works to convert the pedal movement into pressure that is needed to stop the vehicle. The internal seals can wear out over time which leads to pressure bypassing the system internally.
Damaged Brake Hoses
Pressured brake fluid is carried throughout the system via lines and hoses. Over time, brake hoses can become cracked, dried out or deteriorated, potentially leading to leaks and other hydraulic problems.
Brake Caliper Problems
The brake caliper is what clamps onto the rotor to help your car stop. The calipers can develop leaks over time or become damaged. In the case of a damaged caliper, you might notice the car pulls to one side, there is uneven braking or an abnormal amount of heat from one of the wheels.
ABS Hydraulic Control Unit Failure
There are a series of valves, sensors and pumps within the anti-lock braking system's hydraulic control unit. Normal wear and tear can eventually lead to issues with the electronic controls and cause the pedal to feel soft. Because the module is so advanced, professional diagnostic equipment might be needed to verify the issue.
Brake Booster Issues
Modern cars are equipped with brake boosters as part of the system. The booster does all the hard work for you—when you press the pedal, the brake booster reduces the amount of pedal effort it takes to stop the vehicle. If the brake booster fails, rather than a soft pedal you might experience one that's hard and requires a lot of effort to push down and stop the vehicle.
What's the Difference Between a Soft Brake Pedal and a Brake Pedal That Goes to the Floor?
When it comes to feeling, there is a significant difference between a soft brake pedal that feels mushy, and one that just goes straight to the floor.
| What the Brake Pedal Feels Like | What It Could Mean | Common Potential Causes | What to Do |
|---|---|---|---|
| Soft or spongy | The pedal feels mushy or springy and requires extra travel before the brakes engage. | Air in the brake lines, low brake fluid or another hydraulic issue. | Have the brake system inspected and properly bled if necessary. |
| Starts firm, then slowly sinks | The pedal initially feels normal but gradually moves toward the floor while steady pressure is applied. | Loss of hydraulic pressure from an external leak or an internally failing master cylinder. | Have the vehicle inspected promptly. Avoid driving if braking performance is affected. |
| Drops immediately to the floor | The pedal has little resistance and travels almost completely to the floor when pressed. | Significant loss of hydraulic pressure, such as a major fluid leak or hydraulic component failure. | Stop driving and have the vehicle towed for inspection. |
These symptoms can overlap, so pedal feel alone isn't enough to confirm the cause.
Why Did My Brake Pedal Go to the Floor After Bleeding the Brakes?
When you change the brake calipers, air can be introduced into the system. Bleeding the brakes removes trapped air from the hydraulic system so pressure can be transferred properly when the brake pedal is applied. If the brake pedal is going to the floor after the brakes have been bled, it means there is either still air in the system or another issue that is causing the hydraulic pressure not to build up.
Common Warning Signs That May Accompany This Problem
If you have had your vehicle's brakes recently serviced, be on the lookout for these other symptoms:
- Brake warning light
- ABS warning light
- Low brake fluid
- Visible brake fluid beneath the vehicle or near a wheel
- Longer stopping distances
- Pulling during braking or a burning smell
Any combination of symptoms should be inspected promptly.
Can a Brake Pedal That Goes to the Floor Be Repaired?
A brake pedal that goes to the floor can be repaired. The repair depends on what caused the system to lose pressure in the first place. The repair could range from replacing a brake hose and bleeding the brakes to replacing other components within the hydraulic system.
How to Help Prevent Brake Hydraulic Problems
Regular inspections are the best way to prevent issues with the hydraulic brakes. Inspections can let you know if there are leaking lines, deteriorating hoses or other developing issues.
Don't Ignore a Brake Pedal That Sinks to the Floor
If your brake pedal feels soft, spongy or sinks toward the floor, don't continue driving the vehicle. Have it towed to a qualified repair facility for a professional brake system inspection. At Gemba Automotive, our qualified technicians can inspect the system to identify any issues.
Frequently Asked Questions
Can I drive if my brake pedal goes to the floor?
No, you should not drive your vehicle if the brake pedal goes to the floor. This is an indication that something is not working correctly and needs to be inspected as stopping performance is significantly reduced.
Why does my brake pedal slowly sink while stopped?
If your brake pedal slowly sinks while you have steady pressure on it, it could indicate the system is not maintaining hydraulic pressure due to leaks or failed components.
Can low brake fluid cause the brake pedal to go to the floor?
Yes, low brake fluid can allow air into the system and interfere with its ability to build the pressure required to work correctly.
Will a bad master cylinder cause this?
The master cylinder has internal seals, and if those become worn or damaged, hydraulic pressure can bypass internally without any noticeable leaks.
Why is my brake pedal soft but there are no visible leaks?
A soft pedal without a visible external leak could be caused by air in the system, an internal master cylinder issue or a brake hose problem.
Why did my brake pedal go to the floor after bleeding the brakes?
Air may still be trapped in the hydraulic system, the brakes may have been bled incorrectly, or the ABS hydraulic unit may require a scan-tool-assisted bleeding procedure. A leak, installation problem or faulty master cylinder may also be responsible.
Why does the brake pedal only sink when the engine is running?
Starting the engine activates brake-booster assistance, so some additional pedal movement is normal. If the pedal continues sinking or reaches the floor, however, the booster may simply be making an existing hydraulic problem easier to notice. The system should be professionally inspected.