Hummer H3T 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

(323)

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

(323)

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 Hummer H3T Hissing noise when brake pedal is depressed Inspection is $105 with $0 for parts and $105 for labor. Prices may vary depending on your location.

CarServiceEstimateShop/Dealer Price
2010 Hummer H3TV8-5.3LService typeHissing noise when brake pedal is depressed InspectionEstimate$124.99Shop/Dealer Price$133.39 - $139.69
2009 Hummer H3TL5-3.7LService typeHissing noise when brake pedal is depressed InspectionEstimate$104.99Shop/Dealer Price$113.41 - $119.72
2009 Hummer H3TV8-5.3LService typeHissing noise when brake pedal is depressed InspectionEstimate$104.99Shop/Dealer Price$113.41 - $119.72
2010 Hummer H3TL5-3.7LService typeHissing noise when brake pedal is depressed InspectionEstimate$104.99Shop/Dealer Price$113.39 - $119.68
Show example Hummer H3T 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 Hummer mechanics

Real customer reviews from Hummer owners like you.

Excellent Rating

(323)

Rating Summary
302
12
2
0
7
302
12
2
0
7

Colby

14 years of experience
66 reviews
Colby
14 years of experience
Hummer H3T L5-3.7L - Exterior Door Handle Replacement (Passenger Side Front) - Longmont, Colorado
Great service, quick and efficient. Wrong color door handle but I agreed to have it installed because I will paint it in the future.

TJ

26 years of experience
362 reviews
TJ
26 years of experience
Hummer H2 V8-6.2L - Evaporation Vent Solenoid - Port Charlotte, Florida
He is very professional, very friendly. He knows his job. I'm very proud of him. I will close my eyes and recommended him to any one who is looking for a good mechanic. Thank you very much. High five. See you again.

Ejnar

29 years of experience
107 reviews
Ejnar
29 years of experience
Hummer H2 V8-6.0L - Oil Change - San Jose, California
EJ came out to my location and repaired car beautifully. I would recommend requesting EJ if at all possible.

James

30 years of experience
925 reviews
James
30 years of experience
Hummer H2 V8-6.0L - Check Engine Light is on - Orlando, Florida
Really knowledgeable and friendly. Will call him again

Excellent Rating

(323)

Rating Summary
302
12
2
0
7
302
12
2
0
7
Number of Hummer services completed
3553+
services done by our mechanics
TOTAL NUMBER OF EXPERT Hummer MECHANICS
200+
experts on our platform

Recent articles & questions

How to Get a Pennsylvania Driver's Permit
Pennsylvania Pennsylvania uses a graduated license program that requires all new drivers under 18 years old to begin driving with a learner’s permit, in order to practice safe driving under supervision before getting their full driver’s license. To receive the...
How to Make Your Own Windshield Washer Fluid
It's easy to make windshield washer fluid with common ingredients. Homemade washer fluid can be more environmentally friendly than conventional fluid.
B1918 OBD-II Trouble Code: Air Bag Memory Clear Circuit Open
B1918 means the air bag memory clear circuit is open and faulty, likely due to a defective wire, instrument cluster, or air bag control module.

All warning lights come on when rainy weather

Hello. This is a water intrusion problem. It sounds like when they installed the harness that something did not get sealed correctly. Most of the time, it is the wiring where it goes into the control module. They need to...

Master Cylinder failure, for a second time. Why? 2011 Nissan Altima

Hi there - I believe your master cylinder failure is being misdiagnosed. I believe the problem is with the brake booster (https://www.yourmechanic.com/article/how-to-replace-a-power-brake-booster) - one of the control valves (vacuum?) to be specific. If this valve malfunctions, it could allow much...

if my truck stalls as soon as i put it in gear is it the Torque converter?

Hi Julian. Thanks for contacting us today. It very well could be that your issue is caused by a worn out torque converter. However, it's also possible that you have a faulty fuel system component or damaged ignition system part...

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