Q: Brakes don't work properly

asked by on

We have replaced the master cylinder and bleed all the brakes and when the car is off the brakes are firm but when the car is running the petal is soft and it goes to the floor and don't come back up like it don't have any back pressure
My car has an automatic transmission.

If your vehicle is equipped with anti-lock braking, you have to either bleed the ABS pump and valving (per Factory Service Manual instructions) or use a bi-directional scan tool to remotely actuate the ABS system during brake bleeding. Otherwise, in an ABS equipped vehicle air will remain trapped in that segment thus causing a low brake pedal. If you do not have an ABS system, the only explanation for what you are describing is trapped air, an internal leak within the master cylinder (of course look for external leaks, but you have probably done that already), or possibly bulging rubber brake lines. If you desire that the brakes be bled by a certified Mechanic, dispatched by YourMechanic right to your location, please request a brake system inspection/diagnostic and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Brakes don't work properly

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: Engine knock

Engine can be caused many things. Depending on the exact nature of the knock, the problem can range from a simple need to higher octane fuel, to more serious problems such as engine damage. I would recommend having a professional...

Q: Q: Abs light randomly coming on.

The traction control system monitors the steering stability of the vehicle and engages when loss of traction has been detected. This is done by the use of electronic sensors that communicate with the Power Train Control Module (PCM) regarding steering...

Q: Car stalling every few days and needs jump. Brand new battery and EGR valve.

Hello, being that the power door locks are controlled by the body control module, a scanner needs to be connected to see if there are any codes present. Also, with a scanner connected, there might be inputs that can be...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...