Q: Q: Brakes

asked by on

The break pedal goes right to the floor but after we pump it a couple times pressure builds up and you hold it and it slowly leaves pressure
My car has an automatic transmission.

One of the most common causes of the brake pedal going to the floor is a loss of brake fluid. Generally, this is easy to detect due to the fact that there is usually brake fluid leaking on the ground underneath the vehicle. The brake booster is a mechanism that uses vacuum pressure to take the force being applied to the brake pedal and amplify it. 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.

Another possible cause for this may be a failing master cylinder. The master cylinder is where the brake fluid is compressed creating the necessary hydraulic pressure the braking system needs in order for it to stop your vehicle. When the master cylinder fails, this may cause a loss of hydraulic pressure which will usually also cause the brake pedal to go to the floor. I would recommend having an expert from YourMechanic come to your location to diagnose your braking system.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Q: Brake line leaking

Hello. Brake lines that go from the front of the vehicle to the back are made of metal. The metal doesn't usually leak unless it is physically damaged or a connection gets loose. If the line is damaged in any...

Q: Motor not starting

If your Ford 150 will not crank, there can be a a few different reasons that could cause this result. Diagnosing the same problem on a newly swapped engine can add additional possible reasons due to additional variables, such as...

Q: Q: Oil leak

As you know, there are many different places in your motor that are sealed by gaskets. I would suggest trying to narrow this down by placing a piece of cardboard underneath the vehicle when parking it at night to test...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...