Skip the auto shop - Our mechanics make house calls

Q: Squealing coming from brake power booster/check valve?

asked by on

When brake pedal is depressed i hear a squealing sound coming from area of Power Brake Booster. It doesn't sound like a mechanical sound. It's more like hissing leaking noise. Like a vacuum leak.

I'm not losing any Fluids from the master cylinder. The brakes also appear to be dragging like a warped brake disc, but i had the disc replaced and machined buy a mechanic.

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

Hello - your problem sounds like a failed vacuum or fresh air valve in the power brake booster, or possibly a ruptured diaphragm in the booster. And, you are correct that this failure will not lose brake fluid. I would recommend having a Brake Vacuum Booster Replacement Service completed by a mobile, professional mechanic, such as one from YourMechanic, to diagnose this problem, get an accurate assessment of damage and cost estimate for repairs.

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: Blower motor issue

Hey there, thanks for writing in. The blower is controlled by the blower resistor/controller and the controller is controlled by the climate controller. You replaced both of these but one of the two is shorted causing the blower to be...

Q: High idling, engine misfiring, car jumps at high RPMs

Hey there thanks for writing in about your 2002 Hyundai Elantra GT. The high idle is likely a bad idle air control motor (or air leak in the intake system). The misfire also may be caused by the factory spark...

Q: My car is running fine but, today i hear a squealing sound when my car is turned on. What could this be?

Hi there. A squealing noise as you've described sounds like a belt noise. A loose, weakened, or stretched belt may be the culprit. However, a weak belt tensioner could also be the root cause of the noise. Either of these...

Related articles

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...
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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.