Q: I hear a hissing nose when I press on my brakes car barely stops

asked by on

When I press on my brakes I hear a hissing noise and and car barely stops

My car has 134000 miles.
My car has an automatic transmission.

This may be related to your brake booster which is mounted on the firewall, and has what is called a master cylinder attached to it. The purpose of the brake booster is to assist in the stopping power of your car when you press the brake pedal. This is done with vacuum pressure, created by using a small diaphragm inside of it that maintains pressure when you are not pressing the pedal. When this diaphragm leaks and vacuum pressure drops, when you press the brake pedal, this can cause the hissing sound you describe. This hissing sound may also be produced when the master cylinder is failing. I would recommend having an expert from Your Mechanic come to your home to diagnose and repair your braking system. If you need assistance, a certified YourMechanic technician can come to your location to perform an inspection of your hissing brakes or replace your brake master cylinder.

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
  1. Home
  2. Questions
  3. I hear a hissing nose when I press on my brakes car barely stops

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: Vehicle sputters and bogs down in drive

Hey there, it sounds like you may have an issue with fuel getting to the engine. The most likely cause of this is a failed fuel pump or a clogged fuel filter. With these conditions, I would recommend having a...


The output of the alternator should be tested and all connections confirmed. If the charging system is working correctly, the possibility of parasitic power loads should be considered. If you want this issue resolved by a certified Mechanic, dispatched by...

Q: My brakes squel even though I have recently replaced pads and rotors.

Sometimes inexpensive brake pads will squeal even when new. Something you can try is to use some anti-brake squeal spray or lube designed for the backing plates of the brake pads. These can help with the high frequency vibrations that...

Related articles

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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.