When you apply maximum force to the brake pedal you re telling your car you want to slow down very quickly.
Why does my brake pedal go to the floor when i start my car.
The brake system in your car is a sealed hydraulic system and relies on close tolerances between the brake pads and rotors or the brake shoes and drums.
The brake pedal is what you use to communicate to the car that you want it to slow down and it should always function the same.
When you are ready to leave for work after your car has sat for a prolonged period of time check the ground underneath your car for puddles.
So i ruled out the master cylinder since i just replaced it last week.
Another common reason why your brake pedal may go down to the floor is because you are running low on brake fluid.
The most common reason this happens is because you have a leak in one of your lines.
If it s low top it off to the mark on the side of the reservoir.
A brake pedal that feels mushy spongy or that slowly sinks to the floor when depressed can be best described as brake pedal sink.
If the booster is bad then the full amount of force needed to activate the master cylinder and pressurize the brake fluid isn t going to be there.
The pedal will go all the way to the floor and the car will be harder to stop.
Also if a leak occurs in the system it will be unable to build pressure due to the lack of fluid causing the brake peddle to travel to the floor which can be followed by the brake system.
Check your brake fluid.
If the brake shoes are worn the air gap between the shoe and the drum will be enlarged making the brake pedal travel downward beyond its normal throw.
I bled the brakes and the master cylinder at least 10 times.
The booster is a mechanism that uses vacuum pressure to take the force being applied to the brake pedal and amplify it.
If your brake pedal sinks towards the floor when you are stopped while your foot is on the brake or does not feel as firm when the brakes are applied this could indicate you are having some sort of trouble with.
This article applies to the ford f 150 2004 2014 and f 250 super duty 2005 2014.
Low brake fluid level.
I have a nice firm brake pedal when the car is not running as soon as i start the engine the pedal goes almost to floor.
When you push down on the brake pedal a little you re telling your car to slow down a bit.
If you hit your ford f 150 or super duty s brake pedal and it goes to the floor stop the vehicle and don t drive it until you find a solution to this problem.