Skip the auto shop - Our mechanics make house calls

Q: BRAKE PROBLEM

asked by on

Yesterday I started my vehicle, applied brakes before putting in reverse, and noticed a continous hissing sound every time I apply the brakes. The brakes are not working properly. It takes pumping several times and is very hard to stop! The hissing sound is continous as long as the brakes are applied. This is an all of a sudden problem ! Havent heard this before until yesterday! Brakes working ok prior to yesterday. Noticed brakes have gradually required a little more stopping time but no hissing sound!.SUGGESTIONS? Thanks in advance........ Sincerely. Bobby Graham . ..

My car has 123000 miles.
My car has an automatic transmission.

A: Hi there. It sounds like the brake booster ...

Hi there. It sounds like the brake booster could be failing. Many times a leaking master cylinder is the cause. The master cylinder can leak brake fluid into the booster over time without anyone really noticing. The brake fluid is corrosive and weakens the vacuum chambers in the booster which eventually fail and produce the hissing sound you're hearing. I suggest having a technician perform an inspection to avoid replacing unnecessary parts. Your Mechanic has several available technicians that can assist you with a hissing noise when pressing the brake pedal inspection.

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・Save up to 30%

Get a quote

What others are asking

Q: Misfires and low oil pressure when stopping. 2002 GMC Savana 2500

Hey there, thanks for writing in about your 2002 GMC Savana. If you are getting misfiring, then you should have a Check Engine Light on. The light should be scanned to get the codes to see what cylinders are misfiring....

Q: Truck wont go in gear 1989 Chevy C1500

Hello - I suspect there is still air in the hydraulic line for the clutch. If you bleed the system depending on gravity to bleed it for you, it just won't bleed properly. Pressure-bleeding it from the bottom-up is sometimes...

Q: My 1988 Chevrolet Silverado 1500 has power in reverse but spits and sputters with hardly any power in drive.

Hello and thank you for your question. Sounds like the manual valve is out of adjustment and the transmission is applying the forward and reverse input clutch at the same time. This will cause the issue you are having. You...

Related articles

How to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
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...