Check the master cylinder first.
if brake pedal is soft , either there is air in the system ,a brake fluid leak, or brake linings and pads are worn allowing the pedal to travel to far if there is a fluid leak, this can usually be found by getting under vehicle and looking at inside of wheels for brake fluid
Loose connection? Stripped fitting (cross threaded or overtightened) Broken brake line?
Master cylinder.
Pull all 4 wheels and inspect the brakes. Something came apart or broke in one of the wheels.
Make sue brake fluid reservoir at top of master cylinder is filled to proper levelMake sure parking brake is fully releasedAnswerMake sue brake fluid reservoir at top of master cylinder is filled to proper level Make sure parking brake is fully released
Check the ABS Dump Valve. If not operating, little or no fluid to rear brakes.
Just hitting the brakes will not stop the car if the brakes are faulty. Pressing the brake pedal starts a process by which brake fluid disperses the force of your foot by increasing the surface area of the fluid being pushed. This increase in force is then transferred to "soft" pads that press against the moving wheels of the car. This friction is what stops the car. However, if the brake pads do not make contact with the wheels, the brake lines carrying he brake fluid are severed, the brake fluid is low or empty, or the connection between the brake pedal and the whole system is faulty, then the brakes will fail.
If your brake peddle goes to the floor, you have lost brake fluid from your master cylinder in the engine compartment. Check your rubber brake hoses at each of your wheels, look for any signs of leaking brake fluid at your wheels, connections,lines, and master cylinder.
That your emergency brake is on or that you are low on brake fluid or the brake pads are getting thin or some other brake malfunction
First the driver puts pressure in the foot brake, which then pushes a small piston, the piston then exerts pressure in the brake fluid. Then the increased pressure is transmitted through the fluid in the brake lines to a larger piston within the wheels of the car. Each piston pushes in a brake pad which the rubs against the brake disc, and the wheels motion is slowed down by the force of friction.
If you are driving and need to brake, but find your brake pedal is getting closer and closer to the floorboard, you need the check your fluid. Eventually your brakes will not have enough fluid to create the pressure needed to apply the brake pads properly and you risk accidents.
Rear brake cylinders or calibers are corroded and need to be replaced. Also drain the replace all brake fluid.