BMW 230i Hissing noise when brake pedal is depressed Inspection at your home or office.

Our certified mobile mechanics come to you 7 days a week between 7 AM and 9 PM.

Estimate price near me

Service Location

Customer Ratings

(6,643)

How A Diagnostic Works

Instantly book a certified mobile mechanic to come to you

Mechanic diagnoses the problem and quotes necessary repairs

Your vehicle is ready to go

Fair, upfront & transparent pricing for all services

Our certified mobile mechanics can come to you now.

Customer Ratings

(6,643)

Hissing noise when brake pedal is depressed Inspection Service

How much does a Hissing noise when brake pedal is depressed Inspection cost?

On average, the cost for a BMW 230i Hissing noise when brake pedal is depressed Inspection is $95 with $0 for parts and $95 for labor. Prices may vary depending on your location.

CarServiceEstimateShop/Dealer Price
2020 BMW 230iL4-2.0L TurboService typeHissing noise when brake pedal is depressed InspectionEstimate$114.99Shop/Dealer Price$124.99 - $132.49
2019 BMW 230iL4-2.0L TurboService typeHissing noise when brake pedal is depressed InspectionEstimate$94.99Shop/Dealer Price$105.01 - $112.52
2021 BMW 230iL4-2.0L TurboService typeHissing noise when brake pedal is depressed InspectionEstimate$94.99Shop/Dealer Price$105.01 - $112.52
2017 BMW 230iL4-2.0L TurboService typeHissing noise when brake pedal is depressed InspectionEstimate$94.99Shop/Dealer Price$104.99 - $112.48
2018 BMW 230iL4-2.0L TurboService typeHissing noise when brake pedal is depressed InspectionEstimate$94.99Shop/Dealer Price$105.02 - $112.55
Show example BMW 230i Hissing noise when brake pedal is depressed Inspection prices

Brakes are the most important safety components on your vehicle. Despite that importance, it’s easy to take them for granted, at least until your car begins to do strange things. Ordinarily, pressing your brake pedal should result in only the car slowing down or stopping. If you hear a hissing noise when the brake pedal is depressed, it may mean there’s something that needs to be repaired in the system.

How this system works:

On many cars, the master cylinder works in tandem with a brake booster. The brake booster is mounted to the firewall, generally in front of the steering wheel position, and the master cylinder attaches to it. The entire point of the brake booster is to make it easier to press the brake pedal and slow or stop the car.

Your brake booster works on vacuum pressure. There’s a diaphragm inside that is responsible for maintaining pressure when you’re not pressing the pedal. However, when you do press the pedal, a push rod moves forward within the booster and into the master cylinder. The side of the diaphragm facing the cabin vents to atmospheric pressure, while vacuum is maintained on the other side.

This then equalizes with pressure on the other side of the diaphragm, providing the boost needed to make pressing your brake pedal easier. The hissing noise you hear when the brake pedal is depressed could be nothing more than ordinary operation, or it could be a sign of a deeper problem. There are a couple of different potential issues here, some more severe than others.

Common reasons for this to happen:

  • Leaking Vacuum Line: Your brake booster is supplied with vacuum from the engine via a vacuum hose. It’s usually located near the firewall. If this hose has a leak, it can be heard within the cabin.

  • Leaking Brake Booster Diaphragm: The diaphragm that’s responsible for maintaining pressure within the brake booster can fail, particularly if the master cylinder is leaking fluid into the booster. When this happens, you’ll hear a hissing sound when depressing the brake pedal, but the pedal itself will be much, much harder.

  • Damaged or Missing Foam Silence: Most cars equipped with brake boosters also have a foam silencer that’s designed to help prevent you from hearing that hissing sound. If the silencer has degraded or been damaged, you’ll hear the hissing sound.

  • Failing Master Cylinder: If you hear a hissing sound and suspect that the problem is the diaphragm in the booster, the actual cause is likely the master cylinder beginning to fail. Signs that the master cylinder is leaking into the brake booster include low fluid in the reservoir with no visible leaks.

What to expect:

A top-rated mobile mechanic will come to your home or office to inspect your brake system, including the brake pedal operation, the brake booster and listen to the hissing sound. The mechanic will then provide a detailed inspection report that includes the scope and cost of the necessary repairs.

How it's done:

The mechanic will need to crank the car in order to verify the hissing sound, and a test drive may be necessary to duplicate the complaint. Additionally, the mechanic will inspect the brake pedal operation, the condition of the brake booster, the master cylinder, the level of fluid in your system and more.

How important is this service?

Power brakes are wonderful things, making it far easier to work a brake pedal that would otherwise require significant force to activate. While the hissing sound may be a sign of nothing more dangerous than a failed piece of foam, it could be a symptom of something much more worrisome – a damaged brake booster and a failing master cylinder. You cannot afford to take chances with your brake system. One of our professional mechanics can inspect the entire system and determine if there’s cause for concern, and what needs to be done if there is a problem.

Fast and easy service at your home or office

Backed by 12-month, 12.000-mile guarantee


Meet some of our expert BMW mechanics

Real customer reviews from BMW owners like you.

Excellent Rating

(6,643)

Rating Summary
6,192
205
60
44
142
6,192
205
60
44
142

Ruben

14 years of experience
86 reviews
Ruben
14 years of experience
BMW 528i L6-2.8L - Tune-up - North Hills, California
First time experience with yourmechanic service. I availed a tune up service and Ruben was professional and knew what he was doing. He was also friendly and very knowledgeable. I will avail his services next time I need it. Next one is brake pad and rotor replacement. I will give an update soon.

Leng

21 years of experience
7 reviews
Leng
21 years of experience
BMW 330Ci L6-3.0L - Car idle is rough Inspection - Seattle, Washington
Experienced, Knowledgeable, Straightforward, and Reliable.

Jay

37 years of experience
953 reviews
Jay
37 years of experience
BMW 328i L6-3.0L - Crankshaft Position Sensor - Fontana, California
Great mechanic.

Harish

27 years of experience
588 reviews
Harish
27 years of experience
BMW 328xi L6-3.0L - Thermostat - Charlotte, North Carolina
Great mechanic. Very friendly.

Excellent Rating

(6,643)

Rating Summary
6,192
205
60
44
142
6,192
205
60
44
142
Number of BMW services completed
73073+
services done by our mechanics
TOTAL NUMBER OF EXPERT BMW MECHANICS
1100+
experts on our platform

Recent articles & questions

How Long Does a Clutch Last?
It’s a fact of life that a car clutch will almost certainly wear out before your car does. That’s because, even...
Symptoms of a Bad or Failing Courtesy Light Bulb
If your car's courtesy light, also known as the dome light, is dim, flickering, or not working at all, you may need to replace its bulb.
P0479 OBD-II Trouble Code: Exhaust Pressure Control Valve Intermittent
P0479 code means there is an out-of-the-ordinary voltage reading from the exhaust pressure control valve circuit often due to damaged wiring.

How to activate the rear defogger?

Whether your Accord has a manual A/C, auto A/C or a built-in navigation system, activating the rear defogger is done in the same way. Find the button on the dash that says “Rear” and has a picture of the defogger,...

Hydraulic lift gate not working

The lift gate could have many problems that might cause it not to work. I would recommend taking the truck to the lift gate manufacturer or the dealership to have them look over the problem. They will have all the...

Acceleration problems in 2004 Volvo S80

The first thing to determine is whether the problem involves the engine, or transmission. If the engine is running rough, or the turbo is not working properly, the engine will be down on power, and will not accelerate as it...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com