Brake pedal keeps going to the floor. What is the cause ?

Your main brake system failed not the abs system

Hi, it sounds like you have air getting into your clutch slave cylinder as thats what causes the pedal to sink to the floor when you have air in the system . As for the horn your brake pedal could be touching a bare horn cable that must be some were on the car floor or outside the car . You will have to check inside and out side for a bare wire next to the brake pedal.

If power booster is bad it will cause a hard pedal, If master cylinder is bad. pedal will go to floor .running or not. when the brake pedal goes down at a standing stop, it is the master cylinder losing vacuum.( replace). Hope this helps you!

It is very difficult to diagnose this problem with the little bit of information you gave. If the brakes are drum brakes check to see if the brake cylinder is working and has no leaks, lift the rubber seals and make sure there are no leaks there, check the brake adjuster make sure that works okay. If everything works and you bled the brakes properly, then the problem is most likely is the master cylinder or the wheel cylinder.



While bleeding the brakes always make sure you check the master cylinder reservoir to make sure the fluid level is up so you do not get air in the brake lines. When bleeding the brakes did you have someone press down hard on the brake pedal hold the pressure on the brake pedal when opening the bleeder then push the brake pedal to the floor keep it there, until you tightened the bleeder, then pump the brakes up and hold it there, while you repeated the bleeding operation by opening the bleeder when the brake pedal go\'s to the floor keep the pedal down until you tighten the bleeder and then pump the brake pedal back up then check the fluid level in the reservoir, keep doing it until the brake fluid shows no sign of air.



If the brake pedal is pumping up during the bleeding process and you made sure you got all the air out of the brakes and then the pedal go\'s to the floor, make sure the fluid level is correct in the reservoir and the bleeder is closed tight and there are no leaks in the lines, wheel cylinder, brake cylinder the brake adjuster is working and master cylinder, and if you still have no brakes then it must be a defective piston in the wheel or brake cylinder, if there is a seal problem with the pistons you will not get any pressure to push the brake fluid. let me know how you are doing.

There are several causes for the brake pedal going to the floor:
- Broken seals in brake`s principal pump.
- Broken seals on rear brake's cylinder. (big lieak on wheel)
- Worn rear brake shoes, making seal travel out of cylinder. (big leak on wheel)
- Leak on tubings.
- Empty brake fluid deposit.

WHEN FINISH REPLACING BRAKE PADS.MAKE SURE MASTER CYLINDER COVER ON FLUID LEVEL OKAY.YOU PUMP BRAKE PEDAL UNTIL BRAKE PEDAL GET FIRM HARD.IF BRAKE PEDAL KEEP GOING TO THE FLOOR YOU HAVE AIR IN THE HYDRALIC BRAKE SYSTEM.BRAKE SYSTEM NEED BLEEDING.DONT DRIVE VECHICLE IF BRAKE PEDAL FEEL SPONGY OR GO TO FLOOR.

If the brake pedal goes to the floor with the car off, I would suspect air in the system or some other issue with the service brakes. If you feel and hear a growl in the pedal when it goes to the floor then your abs controller may be at fault. There are many possibilities. In either case if your pedal goes to the floor, then you are looking at a safety issue. Generally the service brake system (regular brake system) is the fault and not the abs. I have however seen a sticking dump valve or faulty wheel speed sensor cause an abs issue. Start with the basics first. Leaky wheel cylinders/ calipers, brake lines, or master cylinder. Verify the hydraulic integrity of the service brakes before tackling an abs issue.

What part is bad that is leaking? Sounds like you are getting air into the brake line and this will cause a problem with te pedal going to the floor

make sure brake fluid is full. then pump brakes for one minuite check the fluid to see if it went down or stayed full. if it went down then check the system for a leak . if it stays full then you will need a new mastercylender . i dont think you have a vacum problem cause this causes a verry stiff brake pedal not one that goes to the floor