Question about 2002 Chevrolet TrailBlazer

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When I press my brake pedal there is a sound of air escaping and the car takes a longer time to stop; I was told that I have a faulty brake booster. Is this correct?

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That is correct. The booster has a diaphram in it that must have a hole in it that is letting the vaccuum escape which is what you are hearing. First, make sure the vac. line going to the booster is not cracked or leaking.

Posted on Sep 08, 2010


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Vacuum brake booster toyota sequoia 1984. Brake Dealer completed diagnostic test showing codes C1223,1247,and 1310. Conclusion the booster needs replacement. Must I? (about $1,000). Safety issue???

Toyota Sequoia's had a lot of problems abs wise> #1 clear codes with a factory software scanner. then drive it to see what returns. I can not see a brake booster setting 3 codes that are ABS/VSC problems #2 how does the brake pedal feel If it is high and hard pedal then the booster is bad if the engine speeds rise as pedal is depress and you hear escaping air the booster is bad. #3 ABS/VSC are supplemental systems to the normal braking soit will take longer to stop and a possible skid could occur. but you will stop leave more traveling space you should be fine.

May 07, 2014 | Toyota Cars & Trucks

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When i press the brakes the pedal goes to the floor and i get like a air sound coming from the pedal area

it appears that the brake booster is faulty and that is the air noise . Replace the booster. The brakes going to the floor indicates air in the system bleed the brakes starting at the longest line first finishing at the shortest line.

Nov 11, 2013 | 2004 GMC Sierra 1500 Crew Cab

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Brake Problem

yes but up to a point
the brake pedal should move about 1" to take up the pedal free play and then be applied smoothly as you press further
the harder you press the more solid stopping action you will get
that way you can feel the brakes working so that you can adjust the braking action for stopping
there should be no hissing noise that occurs when the brakes are being applied
you say hydro booster which is hydraulic booster but a hissing noise will come from an air leak in a vacuum brake booster which indicates that it needs repalcing

Apr 16, 2017 | 2001 Dodge Durango

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Brake pedal has alot of back pressure and car moves in gear.Have to press real hard to stop.How to check abs pump if has one where or brake booster or master cylinder?Don't know how to trouble shoot or...

The air seeping is a dead giveaway. Your power brakes are now manual brakes, but stiffer. The diaphram in the brake booster has torn and the hissing noise is the engine vacuum escaping (you hear it louder when you depress the pedal right?). Replace the booster and you will be fine. The brake lights probably don't work because you can't push the pedal down far enought to release the switch. Please rate. Thanks.

Sep 03, 2011 | 1995 Mercury Cougar

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1999 Buick Century Custom _ Brake Problem My 99 Century has little to no assist and it makes an air hissing sound when depressing the brake pedal. I think that this means that I have a faulty brake...

nope you have to replace them.when brake booster diaphram leaks you cant plug them.i have bought one at salvage yard in good shape.until i got a new one.get your brake booster from inside salvage yard where they stock them inside out the weather.dont take any brake booster off old outside cars been in all kinds bad weather. there vacuum diaphram probably dried up will leak also.

Jun 11, 2011 | 1999 Buick Century

1 Answer

When you press on the brake it sounds like Air

Your vehicle has what is called a brake booster on it. It is mounted on the firewall under the hood and your brake master cylinder is mounted to that. The brake booster works off of vacum pressure that your engine builds. When the booster goes bad the vacum pressure escapes and it sounds like a hiss at your pedal. This problem will get worse and can cause your pedal to go to the floor. This could be a dangerous situation for you. I recommend that you get this checked out for safety reasons. Hope this helps. If for some reason this goes out on you and you are on the road you can find the big vacum hose that goes into the booster, take the hose off and plug it with something. Please note if you do this you will not have power brakes after that you will be on manual brakes and it takes a lot more pressure to stop your vehicle so drive slowly and not to close until you get it fixed. If the booster goes all the way out your engine will run rough or die at idle. If you do have to block the vacum line your engine will run smooth again but it may set off the check engine light. Take care, Roger

Feb 07, 2010 | 1990 Volvo 740

1 Answer

2002 escape hissing from inside under/by brake pedal. when pressing on brake hissing stops. Is this the booster? Help

You have done the brake booster.Its a mechanic shop job.If you jab the brake a few times in a short sequence,the motor should slow down just a fraction.It might.Hope this helps

Feb 03, 2010 | 2002 Ford Escape

1 Answer

When u press on the brakes on my expedition, i hear air escaping.

If it is a constant hiss with your foot on the pedal, you have a bad brake booster. If you hear a hiss, and nothing else while holding the pedal, it is the air escaping from the booster boot, and should not pose a problem.

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2 Answers

Air escaping

this noise is a vacuum leak at the power brake vacuum booster due to a tear in the booster vacuum diaphragm, u should have this replaced ASAP, it the leak gets worse the brakes will become very hard to push and will limit your ability to make a safe and timely stop.

Jan 30, 2009 | 2004 Volkswagen Golf

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