Brake Pedal Hissing When Pressed

The noise only appears when the brake pedal isn't pressed. Engine does not sound like it has a vaccum leak, just the hissing when the pedal is pressed. Brake pedal makes hissing sound when depressed like air leakage; intermittently very difficult to depress brake pedal with a lot of force applied (typically if pumping brake), leading to increased. I also had someone listen for that sound in the engine compartment when I pressed brake pedal. I even got a hold of one of those Ford antilock brake bleeder tools as the problem started after a brake line let loose and I suspected air got in the anti-lock brake system as well. I Had To Press Really Hard On The Brake Pedal To Get It To Stop. Booster replaced. Any ideas what this could be? brakes seem to work as normal. New to Cerbera ownership and just wondering if this is normal! When I brake I hear a hissing sound like air is being pushed out from somewhere by the foot pedal, I only noticed it yesterday as it. hissing brake pedal ? The brakes seem fine, they work the brake pedal suddenly seems soft and then it gets some pressure and gets harder. Brakes that are less responsive than they should be or a brake pedal that seems to drop when pressed may indicate a leak in the brake system or that your master cylinder needs to be replaced. leaking air behind brake pedal, is there a simple fix 1 Answer. lately I can hear a sound like air escaping when the brake pedal is released. it only does it after you release the pedal and hisses until the pedal returns to the up position. If you notice a hissing sounds from brakes while inside the passenger cabin, that's the sign of a failing vacuum booster. The last few days when you press the brake pedal to stop, it will make a "high pitched /siren type" noise. But then I noticed that the sound also comes when pressure is placed on the brake pedal itself. That suggests the servo is working normally. I had a similar hissing sound when my brake booster went bad. If your hearing a hissing sound inside your blazer when you push down on thebrake pedal, The most likely cause would be a brake booster failure. The brake booster is mounted between the brake pedal and the brake master cylinder. BEFORE replacing the booster, the pedal was spongy and weak, and depressing it often lead to a strong hiss. If the pedal stays up and does not drop the booster has a problem. at about 40k miles, the brakes pedal started hissing and the brakes felt spongy. I noticed that when I hit the brakes hard I hear a hissing noise. The pedal goes to the floor the first time you press it, then starts to feel more normal after being pumped a few times. Stop the engine and press the brake pedal a few times, you should get 2 or 3 presses until ther hissing stops and the brake pedal goes rock hard again. 9 TDi Estate. Air hissing when I pressed break pedal, I am taking the car in to the dealership tomorrow. In general, the noise should happen only while the pedal is actually moving - if you press the pedal and hold it totally still, and the hissing continues, then there may be fault, otherwise. view details; aug 02, 2017 - pasadena, md - service brakes tl* the contact owns a 2009 ford edge. The hissing can be stopped by reapplying the brakes or lightly tapping the brake pedal (kind of like hitting the side of you tv for a better picture. It has progressively gotten worse, and now we have about 70k miles on it and sometimes the brakes are extremely difficult for my wife to depress, especially at low speeds and when going uphill. I av a ford transit tipper, and when I kicked my van in last night ther was an hissing noise like air coming from the brake pedal and when I pushed my brake pedal down it stopped. 1999 Solara with approx 130K miles. Hold the pedal down and start the engine. Brake booster vacuum leak. Posted: Sat Apr 29, 2006 8:39 pm Post subject: Clicking sound when brake pedal is pressed Every now and then , my 03 MPV LX ( 23k miles ) makes a clicking sound loud enough for me to hear in the cabin when I press on the brake pedal. hello, 2006 f150 5. Saturday night I get back in it to move it an press the brake pedal and hear a very loud hissing noise almost like the sound you hear when using a foot pump!! It sound like it was coming from the passenger footwell. This is in stark contrast to a faulty master cylinder that will result in a brake pedal that fades to the floor. The other side is vented to atmosphere when the pedal is pressed. I noticed that when i take off from a stop, the second I let go of the brake, the vibration stops, and I smoothly take off from the stop and continue on without a. Brakes are the most important safety components on your vehicle. 06-10-10 08:37 AM - Post# 1927937 I have a leaking brake booster on my 98 4X4 5. Kinda annoying. One thing I did find weird was that while pushing on the brake pedal with any amount of pressure you can hear what I would describe as a hissing sound coming from above the brake pedal area like where the push rod (or whatever it's referred to as) goes through the firewall and to the brake booster and brake MC. 0e K12 manual. Q 2000 528i I’m having a problem with my BMW. Engine on and each time you depress the brake pedal quickly it results in the "whoosh" sound - it very much sounds like a bellow blowing air. I dont know if the brake paddle sinks or doesnt sinks. have 93 dakota 5. There was a new one that came with the car, so I installed it. leaking air behind brake pedal, is there a simple fix 1 Answer. A local brake shop diagnosed the problem as failure of both the brake booster and master cylinder, simultaneously. Pump the brake pedal several time with the engine off, then keep it slightly pressed down. re: Sound when the clutch pedal is pressed? That's the clutch release bearing causing the noise (happens when the clutch is pressed and goes away on releasing). You can drive and it will start hissing but when you press the pedal a bit it goes then either comes back or goes random. it only does it after you release the pedal and hisses until the pedal returns to the up position. its more like a slow honking noise when the pedal goes back to upright position If it is a hissing noise, it most likely means that your power brake booster is about to fail. When i had the squeaky clutch pedal in my Mazda, I was sure it had to be in the clutch master cylinder. Brakes themselves, pads, rotors, calipers all normal and quiet. Any recommendations (or links) on how to troubleshoot that?. The hissing comes back when the brake is released but if you release the pedal VERY slowly sometimes the hissing will not come back immediately. Cannot be heard from the engine bay. No hissing with this only. It seems I don't have any problem but the sound is audible and it's bugging me. The sound is audible near the brake pedal location. There is a loud hissing inside the cab when pedal is pressed , engine on, and pedal will slowly drop to the floor. My brakes are "spongy" and I literally have to use both feet to stop my vehicle. If pumping the pedal changes the force by which is applied to the brake pads then you have a failed master cly. With the engine off, press the brake pedal down several times. Brake booster problem hissing sound; Whoosh sound when you apply the brakes; Cause. brakes are VERY hard to press, all the time. i noiticed a hissing noise coming from the brake pedal. With the engine off, press the brake pedal down several times. recently, a car stopped suddenly if front of me and I hit the brakes very hard to stop. The valve closes the pull of vacuum to the rear of the diaphragm and the engine vacuum is only pulling on the front while atmospheric pressure is allowed into the rear of the booster. hissing brake pedal ? The brakes seem fine, they work the brake pedal suddenly seems soft and then it gets some pressure and gets harder. Except when I press the pedal, then the idle speed increases. This answer is applicable for many BMWs in addition to the one listed below. A new o-ring stopped the hissing. strange noise when brake pedal is pressed. After 12 years, this isn't so farfetched. It will not lead to a breakdown and it should be ok to drive to Pune of the car is healthy otherwise. back in June 2018. CAUTION: Wear protective goggles when performing the following procedure!. You should be using Castrol GTLMA DOT 4 brake fluid. When you're out of brake fluid, your brakes simply won't work. I find that there are several answers which suggest leakage of brake fluid as a possible reason for the brake pedal not returning to its initial position. CX-9 owners, especially those in hotter climates, have been telling harrowing tales of brake problems centered around: A possible loss of power assist making the brakes really hard to push at times; A sudden loss of braking ability with super spongy pedals; A strange, hissing noise coming from the pedal area. I have a 1992 coupe and over the past week noticed the brake pedal at times extremely hard to press down and feeling like the car isn't going to stop. any insight on this?. Except when I press the pedal, then the idle speed increases. It goes away when I press the brake pedal or turn the steering wheel either direction. Braking on the van seems perfectly fine, but after braking, there is occasionally a hissing noise after releasing the pedal. So we changed the master cylinder and bled the brakes with the car off (not sure if this should have been done with the engine on or not), but when i started driving it again immediately afterwards, i noticed a considerable hissing noise which would stop when the brake pedal was pressed. Sounds like the brake booster to me, if the brakes work fine, maybe its not big enough to impact the braking performance, but it will probably eventually. The brake pedal will go down half way and stick with a loud vacuum leak ‘whistle’. Hey Everyone, so I have a small problem with my 2007 Rabbit. At the same time the air valve moves allowing atmospheric pressure in. this does not happen all the time only sometimes. For reference, Im 6'4" and 220lb, so if I can get in the footwell, anyone can!!. Air hissing when I pressed break pedal, I am taking the car in to the dealership tomorrow. gloves, and jeans this was a bit of a cause for concern. This type of noise is normal. Brakes themselves, pads, rotors, calipers all normal and quiet. Hi All, I have a 2010 Skoda Octavia 1. The booster is a tanden design, when the brake pedal is at rest there is a vacuum (supplied by the engine) on boths sides of the two diaphragms, when the brake pedal is pressed the plunger valve opens to allow atmospheric air into the booster to fill the backside of both diaphragms, this added *normal* air pressure increases the force on the. When I apply the brakes, there's this hissing sound that I first thought might be coming from front brake linings. When job was done the brake fluid was over the max level at the reservoir, so i took some fluid out with syringe. They use engine vacuum to provide power assist when braking. Engine on and each time you depress the brake pedal quickly it results in the "whoosh" sound - it very much sounds like a bellow blowing air. The feel of the pedal should change. In general, the noise should happen only while the pedal is actually moving - if you press the pedal and hold it totally still, and the hissing continues, then there may be fault, otherwise. I again need to bleed. A brake pedal that would make a whistle type sound when the brake was applied and released. At that point the brake pedal should be rock hard. The hissing happens when the car is turned on. If the steering wheel vibrates when pressing on the brake pedal, then the pad or rotor surface is uneven, causing feedback in the steering wheel. bolts to it. What would cause a hissing noise to come from the brake pedal on a 1990 ranger when it is pressed down to the floor and the brakes barely work? Vacuum brake booster is defective or the hose going. Hissing noise from brake pedal area. There should be a slight hiss when the brake pedal is depressed. The pedal hisses loudly like air is being released when I apply the brake. Anyone replaced a brake booster by themselves. sometime it works when brake paddle is pressed twice. Like you, I didn't notice a loss in braking power, but without the MAF it didn't severely affect the engine speed. Should add that's it's not a continual hisswith the brake pedal pressed down it lasts a couple of seconds and then stops. Sounds like the brake booster to me, if the brakes work fine, maybe its not big enough to impact the braking performance, but it will probably eventually. When the car is stopped and its *Really* quiet I can hear it when I am not pressing my brakes. In fact, I hear the hissing sound increase when I stopped at a light a press harder on the pedal. i primed the clylinder and bled the brake lines. So alas, almost every time the car is running the hissing can be heard, press the brake pedal even a tiny bit and it goes away, release and it comes back. You can drive and it will start hissing but when you press the pedal a bit it goes then either comes back or goes random. Since then when I press the brake pedal the car slows down and stops, but if I continue to press the pedal, it goes down to the floor and make hissing sound/noise as if compressed air is going out of it (like a tyre pump). Cannot be heard from the engine bay. My brake fluid was a thick orange color before I started bleeding all the brakes until it was clear. ABS actuator makes hissing sound when I press the brake pedal. After that incident, when I press the brakes, a loud hissing noise is heard under the dash, the peddle goes down fast then gets very hard to press, while the truck almost will not stop. So we assumed it was the brake booster. I've just replaced the Brake Booster in hopes that was the issue. It passes this test, but there's the hissing sound with the pedal pressed and the engine running. Like you, I didn't notice a loss in braking power, but without the MAF it didn't severely affect the engine speed. When the engine is turned off and I pump the brakes the pedal goes hard after about 3 attempts, but the "whooshing" noise is still there while I "pump". CX-9 owners, especially those in hotter climates, have been telling harrowing tales of brake problems centered around: A possible loss of power assist making the brakes really hard to push at times; A sudden loss of braking ability with super spongy pedals; A strange, hissing noise coming from the pedal area. i noticed a hissing sound every time i press on the brakes. Press the brake pedal. Sounds like the brake booster to me, if the brakes work fine, maybe its not big enough to impact the braking performance, but it will probably eventually. In fact I don't notice anything strange with my brake feel or how my engine runs. The booster uses a rubber diaphragm and a push rod. When I press the brake pedal, I hear hissing or rushing air from behind dashboard/firewall. Hi guys, thanks for the help. BEFORE replacing the booster, the pedal was spongy and weak, and depressing it often lead to a strong hiss. Brake pedal hissing sound The brake pedal hisses for no reason, when i press it down enough to trigger the brake it stops, then when i let off of the brake it does it again, it wont stop. Hissing Sound from Brake Pedal - Dodgy Servo? Important Stuff. So we assumed it was the brake booster. Recently I noticed when I depress the brake pedal before coming to a stop it sounds like there is some air escaping from the pedal. brakes are VERY hard to press, all the time. This is pretty easy to diagnose: You should be able to see brake fluid underneath the car if there's a leak in the system. 06-10-10 08:37 AM - Post# 1927937 I have a leaking brake booster on my 98 4X4 5. Hello all, first of all thanks for your time, I am trying to figure out if I need to replace my brake booster or not on my Forester 2010 with 150k miles: - Symptoms: Brake pedal feels soft to the press After releasing the pedal it goes all the way up without issues. Almost like air being forced out of a small straw or something. Brake pedal makes hissing sound when depressed like air leakage; intermittently very difficult to depress brake pedal with a lot of force applied (typically if pumping brake), leading to increased. In the process I had to change out brake lines and while I was at it I thought I'd paint that ugly rusty master cylinder. The pedal goes a bit spungy I have noticed at the back of brake pedal very light fluid damp over the master cylinder seal. 1 - Hard brake pedal presented itself suddenly. Sounds like the brake booster to me, if the brakes work fine, maybe its not big enough to impact the braking performance, but it will probably eventually. i need some help here, i have a 1994 F150 4. brakes made a hissing sound when pressed and brake pedal went to the floor when pressed. What is the - Answered by a verified Chevy Mechanic We use cookies to give you the best possible experience on our website. CAUTION: Wear protective goggles when performing the following procedure!. I followed the correct procedure for bleeding, and there certainly was a lot of air in the lines, but I noticed that there wasn't much pressure coming out of the rear. Open the hood and have a helper press on the brake pedal with the engine off with everything cold, and listen around the brake booster for a hiss. It should be firm. If I hold the pedal down and start the car, the pedal lowers slightly like it's supposed to. I had this happen in an 83 Pontiac Boneville. I get into my car like I always do, put my foot on the brake, and then push the on/off button. Hissing Sound from Brake Pedal Area - Why? while the brake is pressed, to push this tiny plunger for the speed (cruise) deactivation switch forward (toward the. One factor may be heat. It is not unusual to hear some hissing while pressing the brake pedal - all that is, is air moving into and around the operating parts of the servo. when i release pressure on the pedal the noise stops. It has progressively gotten worse, and now we have about 70k miles on it and sometimes the brakes are extremely difficult for my wife to depress, especially at low speeds and when going uphill. Its not so hard that I have to struggle to press it, rather it is different then when power assist is available. with the engine running, can you hear any hissing, especially when you wiggle the servo vacuum pipe, or any pipes connected to it. * Engine off * Press pedal to floor 8-10 times to remove vacuum * Hold pedal down * Start engine. I'm curious if the MC failed and the pedal was pushed to the floor (wife was driving when pedal travel condition surfaced) if that pressure and increase pedal travel all the way to the limit could harm, damage, or cause the booster to fail. In the process I had to change out brake lines and while I was at it I thought I'd paint that ugly rusty master cylinder. Is everything working properly like temperature controls. It literally sounds like the pedal is hissing. The brakes feel fine and work well. When I press on the brake pedal, it makes a creaking/groaning sound that I can also somewhat feel. Like when you press the pedal, air is being released somewhere. At that point the brake pedal should be rock hard. Now feel how hard it is to press the brake even a small amount. Brake boosters use one of two different methods to enhance the amount of braking pressure exerted by your foot on the pedal. When brake pedal is pressed, it sounds like an air leak inside vehicle in the vicinity of brake pedal. Ford Mondeo IV (2007 - ) - Hearing air when I press the brake pedal. Release the brake pedal and wait 10-15 seconds for the master cylinder pistons to return to the home position. One of the more common causes for the brake pedal going to the floor is a loss of brake fluid. It occurs under low engine RPM, around town, etc. Since then when I press the brake pedal the car slows down and stops, but if I continue to press the pedal, it goes down to the floor and make hissing sound/noise as if compressed air is going out of it (like a tyre pump). 8T with 84000 miles on it. Booster replaced. I noticed a hissing noise today while parked. I did a booster test I found on youtube: pressed the brake pedal multiple times when car was off, held the pedal pressed, started the car and the pedal did go down a little. Remove the adjusting nut to separate the vehicle a balance lever screwdriver bearing clearance is loose but do not grasp the retaining plate and pump it right onto the front of the higher the engine. Is everything working properly like temperature controls. I also hear it if I am standing still and press hard on the brake pedal, is this normal?. If I let off the pedal and press it again and again, the pedal feels soft at the upper range of travel and makes the same airy hissing whoosh sound, but then half way down the pedal feels firm and stays there. There is a loud hissing coming from the brake pedal area inside the car. The following steps tell you what to feel for. but the pedal still sinks slowly to the floor. OK, I don’t know what it is but every time I release the brake pedal, there’s this hissing sound like leaking air coming from the below the dash near the brake pedal. However, in the case of such a leakage, the brake pedal will move forward without any resist. I want to try and get to the booster to see if the vacuum hose is ok or if I see any fluid indicating a leaky m. My brake pedal is soft and continues a slow descent when pressed. The noise is not serious but it can be annoying in city traffic. Release one brake hose at a time. For the your safety, please do this as soon as possible. I find that there are several answers which suggest leakage of brake fluid as a possible reason for the brake pedal not returning to its initial position. If you still can't get a good, hard pedal you probably have bad hoses. If you get the overall ratio in the right range on a truck that size you should not need a booster. Hi there, Ive noticed that when the engine is running on my 300tdi and i press the brake pedal i can hear a hissing noise. But, if you took your foot off the pedal and quickly reapplied pressure, the brakes would still stop the vehicle. Folks, I am hearing a vacuum noise down by my brake pedal on my V70 2001 T5 Wagon with 60K miles on it. Braking on the van seems perfectly fine, but after braking, there is occasionally a hissing noise after releasing the pedal. Today, about a couple hours ago, the brake pedal started to get very hard to push and wasn't stopping the car very well. Your browser does not currently recognize any of the video formats available. there's always a hissing noise, but once I press the brake to the floor it stops. The sound is near the ABS module. Recently I noticed when I depress the brake pedal before coming to a stop it sounds like there is some air escaping from the pedal. Temp should have no bearing if it feels the same with the car running or car off you need a booster. I did not see that the gauge dropped hugely when the brakes were applied, however the air system was taking longer to get to 120 psi after the brakes were pressed and released. If there is a hiss at other times then it sounds like the air-seal in the servo is leaking. Re: A4 spongy brake pedal – 14-06-2010, 11:24 PM i think you either have a faulty servo, or a vacuum leak somewhere. If you have an assistant, get them to press the pedal while you watch -. In the process I had to change out brake lines and while I was at it I thought I'd paint that ugly rusty master cylinder. Edited by 9520Deere 3/20/2012 19:09. Wasn't the quick little hiss on a normal opperating pedal. The car in front of me brake and my brakes were not responding the pedal was locked then went soft resulting in a very close call as I almost hit the car in front of me because I couldn't get the brakes to engage. Turns out, I was losing fluid out of the Master Cylinder. 0 TDCI Zetec in the last few days and last night I started to notice the following issue: 1) I turn the engine on 2) When I press the brake pedal I can hear air being released (while the pedal is going down, not once it stops moving) 3) I turn the engine off 4) I press the brake again a few times. 3 auto has a air hissing noise at the brake pedal it stops when pressed and stars when you take foot off the brake but the brakes work very well no problems at all so hopeing it dont need a new master cylinder so hopeing someone might of had this problem before to tell me what it is or what to check. The most common brake squeak is caused by inferior pads. When we press the brake pedal, the two-way valve also moves. Braking is harder and inconsistent. The vacuum booster uses engine vacuum to increase braking power. It is nothing more than a chamber with a rubber diaphragm that reacts to vacuum pressure. Finally, with the engine running, press the brake. Master cylinder was replaced and the intermittent brake problem went away. I just replaced the brake pads a couple weeks ago but don't this has anything to do with it, but just in case I figured I should mention it. Symptoms: When the brake pedal is not pressed. Hi Everyone, I have a brand new 2020 Rubicon Unlimitedloaded. The brake pedal was stiff causing the car to roll off the driveway and into the side yard. It’s not really all that loud and to tell you the truth I only noticed it the other day (I've driven my Prius for about 4K Miles, since August 2016). It might be easier to get a used booster from a salvage yard first so you can look at it to see how it is mounted. Once you stop the engine, wait for the hissing to stop. New to Cerbera ownership and just wondering if this is normal! When I brake I hear a hissing sound like air is being pushed out from somewhere by the foot pedal, I only noticed it yesterday as it. You will find that if the engine is off the pedal will feel normal for a few pumps and then become firm. The brake pedal will go down half way and stick with a loud vacuum leak ‘whistle’. The hissing is when I brake, and the first time it happened, there was a very loud squealing. Air was escaping. But hissing is a vacuum issue, and likely booster. I have a 2000 Mustang V6. The last few days when you press the brake pedal to stop, it will make a "high pitched /siren type" noise. To diagnose, we started the car to build vacuum pressure to the brake booster. I guess this probably points to the brake booster? I've tried the FSM test for the booster - engine off, pump the pedal until it's hard, hold pedal down, start the engine, check to see that the pedal drops down. Air hissing when I pressed break pedal, I am taking the car in to the dealership tomorrow. This sound is the vacuum brake booster. 3 - there was hissing under the hood. Re: Brake pedal hard to push and air\\vaccum sound Personally I think boosters are an abomination & should only be used on vehicles that are too heavy to stop otherwise. Did you ever figure out what it was? It sounds louder in the morning. Instead the problem is still there, except now I am able hear air coming from the brake pedal if I'm sitting at a red light with the brakes pressed. The following steps tell you what to feel for. Hi there, Ive noticed that when the engine is running on my 300tdi and i press the brake pedal i can hear a hissing noise. But it must stop as long as you do not apply more pressure to the pedal. Whilst stationary, press and release the footbrake a dozen or so times. Cheap brake pads have large metal flakes in the brake material, and when you press the brakes lightly and a flake drags along the rotor, it will squeak. I drove the Cruiser a bit and found that the booster and brakes worked fine when I first pushed the pedal. Brake fluid converts the energy you apply to the brake pedal into the force required to bring your car to a stop. I just now started to hear this soft, hissing, squishy, airy noise coming from the brake pedal inside the cabin when I apply brakes. How to Test For a Bad Brake Booster / Brake Booster Testing How To Fix a Spongy Brake Pedal Chevy Truck. Finally, with the engine running, press the brake. I drive a 2002 Chevy Malibu. Hi (Superbird 440/6) I just pulled up to home with a hard brake pedal and a hissing sound coming from the pedal area. As the driver presses the brake pedal, the vacuum valve blocks the vacuum source located on the pedal side of the booster. it is continuous when i keep my foot on the pedal. Have a 2011 T4R SR5 4x4. I pulled into work this morning and turned the radio off and noticed when i press my brake pedal i get a hissing noise also when the pedal comes back up. Hi (Superbird 440/6) I just pulled up to home with a hard brake pedal and a hissing sound coming from the pedal area. When you're out of brake fluid, your brakes simply won't work. Re: Air hissing sound from brake or gas pedal Sign In Sounds like a vacuum leak. It literally sounds like the pedal is hissing. Pedal slowly sinking would be a leak in the system, a failing master cylinder or contaminated brake fluid. I went to bleed the brakes, but I was getting no pressure at all and noticed a loud hissing noise when I pressed the pedal to the floor. It goes away when I press the brake pedal or turn the steering wheel either direction. I found out that the hissing type of noise from the brake pedal area when brakes are applied is a symptom of worn brake booster. when i press my brake pedal on my ford f150 truck i hear a hissing sound. No lights are on the dash. David Teitelbaum I'm wondering if his brake booster might be leaking. my 1999 solara V6SE has developed a hissing noise under dash recently, the hissing only happen with engine running, but as soon as i tap on the brake lightly, the hissing stopped, and as soon as I take my foot off the brake pedal, the hissing returns, apply brake, no hissing, the hissing noise sound very similar to A/C compressor running, or power steering, but i know AC or power steering were. Several things may be causing this condition: Air in the system, material friction compression, brake hoses expanding, or defective drums. My engine idles perfectly fine and my brake pedal is fine as well. first press on brake has not good effect. No hissing with this only. When I apply my brakes my brake pedal is making a creaking sound. 8T with 84000 miles on it. what could it be? Been noticing a hissing sound when I apply the brakes. Have noticed when the ignition is on and I press the brake pedal that there is a noise which sounds exactly like a bicycle pump coming from the passenger side front footwell. Instead the problem is still there, except now I am able hear air coming from the brake pedal if I'm sitting at a red light with the brakes pressed. Snarling, hissing, and tearing at my clothes, he was a frenzy of. At that point the brake pedal should be rock hard. Leaking brake fluid is unrelated to the brake booster, as one is an air system and the other hydraulic. A more effective test is to get someone in the car to push the brake pedal while you are under the bonnet, engine idling. I turned off air and radio and noticed it was only when I pressed the brake pedal (didn't matter if I was stopped or moving). If you push the pedal in an inch or so the brake booster hissing - Diesel Forum - TheDieselStop. Now takes a lot more force on the pedal to stop. gloves, and jeans this was a bit of a cause for concern. hissing brake pedal ? The brakes seem fine, they work the brake pedal suddenly seems soft and then it gets some pressure and gets harder. Filter by: Will, the blinkers and the brakes are not connected. hello, 2006 f150 5. I was wondering if anyone can help me out? When I press down on the brake pedal while the engine is off, I can hear what seems to be air escaping from behind the pedal. David Teitelbaum I'm wondering if his brake booster might be leaking. Simultaneously atmospheric pressure flows into the rear. This sound is related to the brake pedal for sure. If you notice a hissing sounds from brakes while inside the passenger cabin, that’s the sign of a failing vacuum booster. It was the seal on the bellows on the actuator rod, By upending myself into the footwell, I found that the pedal end had slipped forward from the seating groove. I even got a hold of one of those Ford antilock brake bleeder tools as the problem started after a brake line let loose and I suspected air got in the anti-lock brake system as well. Master cylinder was replaced and the intermittent brake problem went away. :happy I'm guessing it is the brake booster only because it sounded good. If it were a wheel hub it would most likely make the noise while the vehicle is moving or at all times during driving. The pedal goes to the floor the first time you press it, then starts to feel more normal after being pumped a few times. The pedal hisses loudly like air is being released when I apply the brake. Spray WD40 on all the linkages and bushings. Brakes pedal on my wife's car became hard when pressed on (regardless of speed) and noticed a hissing noise when applying brakes. If not, it might be a vacuum leak from the servo or the vacuum pipe from the manifold. THE NOISE WILL GO AWAY AS YOU APPLY DIFFERENT PRESSURES TO THE BRAKE PEDAL, BUT THEN WILL COME BACK AS SOON AS YOU MAINTAIN THE SAME LEVEL OF PRESSURE. People cleaned here should all mechanical life. After pressing the brake pedal and then the start button I see a message on the display that reminds me to press the brake pedal, which I then do by pressing the brake pedal harder. If I pump the pedal a few times, it stops. While you pump the pedal you get the hiss, but it will stop when the pedal goes firm. but it stops when I press the. I had that happen to me once in a crappy old '87. Edited by 9520Deere 3/20/2012 19:09. Does anyone elses brakes hiss with the pedal fully up?. This sound is related to the brake pedal for sure. Hold the pedal down and start the engine. Instead the problem is still there, except now I am able hear air coming from the brake pedal if I'm sitting at a red light with the brakes pressed. Any recommendations (or links) on how to troubleshoot that?. Brake pedal hissing sound The brake pedal hisses for no reason, when i press it down enough to trigger the brake it stops, then when i let off of the brake it does it again, it wont stop. This problem can even damage your engine and lead to more expensive repair.