Skip the auto shop - Our mechanics make house calls

Q: Brake pedal loses pressure

asked by on

The brake pedal loses pressure when I start the car. I can push it to the floor. When I turn the car off, pressure is there. There is also a leak coming from rear passenger wheel.

A: From the description provided, it appears t...

From the description provided, it appears that the symptoms are due to the leak in the brake system that you found in the rear passenger wheel. In order for your power brakes to work correctly, the engine needs to be running. This allows it to supply vacuum to the brake booster, which in turn allows the driver to easily depress the pedal. When the pedal falls to the floor, it is because the brake fluid inside is escaping the system through a leak. This and any repair regarding brakes is a big safety concern and one that needs to be addressed immediately. Enlisting the help of a certified mechanic will allow you to pinpoint the brake fluid leak so that it can be repaired, bled, and rechecked to get your Mustang safely back on the road.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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: Apparent timing chain failure.

Hello there, timing chains in most cases last a long time on your 2003 Ford Mustang. The fuel line repair should not have had anything to do with the timing chain issue. In cases where a timing chain is suspected...

Q: Gear shift lever?

Hello. The gear shift lever can become stuck in park for a variety of reasons. If one of the steering column components was not installed properly then that could be a possible reason as to why the vehicle is not...

Q: When having to quickly brake, pedal goes to floor

Hello there, thank you for asking about your 1988 Buick Reatta. Generally, a hard brake pedal is caused by a problem with the brake booster. A pedal that sinks to the floor usually indicates a problem with the master cylinder,...

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...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
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...