Brake pedal going all the way to the floor.

My brake pedal goes all the way to the floor. I have no brake pressure.
Experienced mechanics share their insights in answering this question :
The pedal going down to the floor usually indicates a loss of hydraulic pressure. Possible causes include a leaking brake hose, a dysfunctional caliper, or a wheel cylinder. Also a master cylinder leaking either externally or internally will cause the same concern. Because brakes are a safety issue, I suggest you have a technician inspect your brake system to determine the cause of your concern.

How to Identify and Fix Common car Problems ?

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One of the most common reasons for your brakes touching the floor would be an issue with your brake fluid. Your fluid being low or air reaching the brake line will prevent the fluid from flowing properly, resulting in a spongy pedal. A bad brake booster is another common cause for a malfunctioning pedal.
The cup seals or the cylinder bore may be worn. Any time that the brake pedal of a vehicle is fading towards the floor, internal leaking or cup seals being bypassed must be considered. A fading pedal that has no external leak is one of the most common master cylinder symptoms caused by the cup seals.
If the brake pedal sinks to the floor when the engine is running then there may be a problem with the brake booster.
Air in the brake line(s) is the most common cause of a soft/spongy brake pedal. If air gets into the brake lines, it can prevent brake fluid from flowing properly, causing the brake pedal to feel spongy or soft. If the brakes are soft or spongy, this is a good time to change or flush the brake fluid.
Usually, your brake pedal will sink if the ABS or master cylinder cannot maintain the proper hydraulic pressure. This inability to maintain hydraulic pressure will not only make your brake pedal sink to the floor, but it will also make it much more difficult to stop your automobile.
Pedal and hold

Hold. Bleed. Repeat. Loud callouts of “pump it up” or “pressure” and “hold it down” can make the garage or driveway sound like a Sunday morning at the Waffle House, but the two-person procedure is a tried and true way to get the brakes bled quickly.

In general, whenever you are bleeding an ABS-equipped vehicle you can do so exactly as you would any other vehicle – stroke the pedal to pressurize the system, open a bleeder, close the same bleeder, and repeat.
With the car turned off, pump the brake pedal four or five times until you get a hard brake pedal. Continue to hold the brake pedal down with moderate pressure and start the vehicle. The brake pedal should drop. If this brake pedal remains hard, there is a problem with the brake booster, such as a ripped diaphragm.
Brake pedals should always feel firm when you press down. If your pedals ever feel soft and spongy, you should immediately get your vehicle inspected, as a spongy brake pedal is a symptom of failed braking components in the car.
Spongy brakes are common and dangerous problems for any vehicle and indicative of a deeper problem. Most importantly, a soft or spongy brake prevents you from stopping as quickly as you need. Spongy brakes could be a sign of a leak, and a small leak can turn into a large one with just a push of the brakes.
Common signs of a faulty vacuum brake booster check valve include the brake pedal being difficult to engage, feeling spongy, or not working at all.
Typically, a vacuum leak will cause situations like hard starting, rough idle, excessive fuel consumption, and engine codes. You might even be able to hear a leak – sometimes a whooshing or whistling sound can be heard with the engine running.
If the ABS system detects that one wheel is slowing down more rapidly than the rest (a symptom of wheel-lock) it automatically reduces the brake pressure on this wheel by opening a pressure release valve in the hydraulic system. ABS also has the ability to build the pressure back up via the hydraulic motor.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Supportive bar attached to brake pedal interrupts proper braking process
ANSWER : It’s possible to have someone alter the brake pedal or adapt a brake pedal from a different vehicle. You may call around to some customization shops to see if anyone is interested in taking on the project. But first, I would try reaching out to the selling dealer with your concern – especially since it is a new model. Good luck.

Why is my brake pedal going all the way down to the floor?
ANSWER : If you are having to refill the brake fluid from it getting low and the brakes go to the floor means you have a leak in the brake system somewhere. You may have a broken brake line, leaking wheel cylinder or caliper. You should not drive the vehicle until the brake system is inspected and repaired from the leak.

Low brake pedal and anti-lock brakes are not kicking in.
ANSWER : The brake pedal is working to stop the vehicle, but there may be air in the controller unit causing the ABS brakes to not function. I recommend bleeding the brake system from the farthest location from the master cylinder to the master cylinder including the ABS unit. If the brakes are still spongy after a full bleed, then the controller will need to be replaced. If you need further assistance with your brake pedal being spongy, then seek out a professional, such as one from Your Mechanic, to help you.

Brake pedal goes 3/4 way to floor
ANSWER : Hello there. This is a more unusual problem, especially given the amount of parts you have replaced. In most cases, the pedal travel is due to either the master cylinder or the brake booster, sometimes both.

Given that these have been replaced, there may be other causes. The most likely fault that comes to mind would be that there may be air in the brake fluid system or one of the brake calipers could be stuck requiring extra travel to engage.

This can occur over time and brake fluid attracts moisture or from replacing the brake components. Some vehicles may be difficult to remove all of the air from when bleeding and require the vehicle to be bleed different ways. If the brake system was vacuum bled then it may need a mechanical bleeding to resolve the issue. If you would like to have this done, a certified mechanic can diagnose your brake pedal issue and determine what should be done next.

Brake sensor is to sensitive causing brakes to flicker while driving. 2005 Mercury Montego
ANSWER : Hi there – your brake light switch needs a minor adjustment. It is adjusted too "tight" or close to the brake pedal lever, or possibly has failed. Adjusting/replacing it will eliminate this flickering problem. I recommend a brake light isn’t working inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.

abs light on brake line broke have been replace I bleed brake line but brake pad still go to the floor now wheels lock up
ANSWER : Hello. If the brake pedal is going to the floor then that means that it is not building pressure. If the brake system has been fully bled and there is no air in it then most of the time it is a bad master cylinder or it can be caused by a bad ABS module. If the brake fluid was low and if air got into the system then the only way to properly bleed it is with a scan tool that would allow you to open and close the valves in the ABS unit. Air gets trapped in these easily if the brake fluid gets low. This can also explain why the brakes are locking up. I would usually use my scan tool to bleed the system out first before going any further. I would also scan the brake control module to see what it is reading as a fault. If there is no air in the system and if there is no prominent code then I would replace the master cylinder first. If you want to check out why your brakes are locking up, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose and repair this.

Hard brake pedal and rear brakes locking up.
ANSWER : Hi. I will help you with this issue you are having with your 2001 Durango. Unless you bled the master cylinder, it is possible there is still air in the system. If you car is equipped with ABS, air could have also gotten trapped in the ABS modulator. If ABS equipped, a bi-directional scan tool would be essential to manually activate the ABS system to clear air from that segment of the lines while you are bleeding the system. It is also possible that in all of this work somehow the proportioning valve has been affected causing the desired pressure differential, front versus back, to get out of spec. Using a 2,500 PSI gauge, you can check the pressures at each wheel and that will definitely give you a clue as to which brake circuit is the issue (or both), whether the proportioning valve is working properly and whether the line pressures at each wheel are within spec. Should you need a second opinion, by all means feel free to contact YourMechanic for assistance and we will diagnose and repair the issue for you.

Brake pedal going all the way to the floor
ANSWER : From the symptoms described, it leads me to believe that your Mitsubishi is experiencing concerns with the master cylinder. A failing master cylinder can duplicate the problems you are experiencing, such as brake pedal going down to the floor. To be 100% certain, i recommend enlisting the assistance of a certified mechanic to inspect the brake system of your Mitsubishi as soon as possible. They will have the experience and tools needed to determine exactly why your Diamante is experiencing this concern with the brakes and assist in making the necessary repairs to ensure your brakes work, especially when you need them most.