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: I have a 06 Hyundai Sonata. It only starts in neutral. Can you tell me why it only starts in neutral

A possibility is the neutral start safety switch is defective. Car designers place that switch in the starting circuit to prevent the car from being started while the car is in gear. Starts in Park or Neutral are the only...

Q: Car headlights randomly turning on and flashing while car is off.

Hi there. Check all of the vehicle grounds to the lighting circuits and the ignition circuits. Make sure that the grounds are cleaned and tightened. A loose ground will cause circuits to malfunction and not work correctly. If you need...

Q: signs

The anti-lock brake system uses sensors in the wheels and other inputs to help control the wheels from sliding, locking up, and to help control the car under certain driving conditions. Issues with the system could include these sensors, any...

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 Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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...