Hissing noise from the pendal 20054 Volvo

I am hearing hissing noise from the pedal area.
My car has an automatic transmission.
Experienced mechanics share their insights in answering this question :
Hi there – your brake power booster has failed – specifically the internal diaphragm. That unit uses engine vacuum for braking assist, but when the diaphragm ruptures as yours has, it sucks in air from inside the passenger compartment. You have probably also noticed that it take much higher brake pedal effort to stop your vehicle. I would recommend replacement of the brake booster by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

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A hissing noise is usually the brake booster leaking air. There could be a leak in the vacuum line, the booster diaphragm, or the master cylinder. A small leak could cause a hissing sound when you press on the brake pedal or let off.
If your brake booster is leaking but your brake fluid level is full, your brake booster would be leaking vacuum. This would mean that your booster has a crack, the check valve is bad, or the hose that connects to the booster has a crack or hole in it.
The noise is caused by air sucked via a cracked brake booster O-ring, silencing foam, or diaphragm. Sometimes, you may notice that the noise goes away when you press the brake or gas pedal. Replacing the brake booster will fix this problem.
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.
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.
Brake pedal difficult to push – The most common sign of a brake booster leak is your brake pedal feeling “harder” than normal. It will require more force to work and increase your stopping distance. If you notice this, you should get your car inspected as soon as possible. This is because it can affect your safety.
hiss. / (hɪs) / noun. a voiceless fricative sound like that of a prolonged s. such a sound uttered as an exclamation of derision, contempt, etc, esp by an audience or crowd.
Have you noticed a hissing noise around your cylinder storage area or piping equipment? This sound is indicative of large amounts of gas seeping through very tiny openings (micro leaks). It may also be indicative of LPG boiling at low pressures and emitting the gas.
It could be a bad solder joint, failing switch contact, faulty connections with a jack or pot, or it could be a faulty component on the board. Try wiggling the battery clip to see if that causes any noise. You can also try to re-route the wires to stop some noises, like whistling.
Squeaking sounds could just mean you`ve got cheap brake pads or hot brakes, or they could be a sign of a bigger problem. Brakes that are overheating can cause a light squeaking, especially when the brakes are still cold. But if your brakes are consistently squealing, you should get them inspected.
It`s imperative to replace brake pads as soon as the wear indicator begins making a noise to avoid more serious problems. Other issues that can cause brakes to squeal include glazing; a crystallization of the pad surface than can occur due to excessive heat caused by slamming on the brakes.
It`s imperative to replace brake pads as soon as the wear indicator begins making a noise to avoid more serious problems. Other issues that can cause brakes to squeal include glazing; a crystallization of the pad surface than can occur due to excessive heat caused by slamming on the brakes.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Hissing noise from the pendal 20054 Volvo
ANSWER : Hi there – your brake power booster has failed – specifically the internal diaphragm. That unit uses engine vacuum for braking assist, but when the diaphragm ruptures as yours has, it sucks in air from inside the passenger compartment. You have probably also noticed that it take much higher brake pedal effort to stop your vehicle. I would recommend replacement of the brake booster by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

Hissing noise.
ANSWER : This may be a sign of a vacuum leak. High idle speed, stalling and hissing sounds are common signs of a vacuum leak. When a vacuum leak is present in an engine, this causes an excessive imbalance in the air/fuel ratio which creates a loss of power and causes the motor to run at a much higher RPM as a result of the increased oxygen present in the fuel charge being injected into the motor. I would recommend having an expert from YourMechanic come to your location to diagnose your vacuum leak as these can be very difficult and time consuming to trace.

Hissing noises coming from the gas tank area
ANSWER : Hey there. From your description, it sounds like you are hearing the Evaporative emissions system perform its routine checks. The computer will check the fuel tank and evaporative emissions hoses for leaks. If conditions are right, the pressure will build inside the tank during testing and the computer and may vent that pressure causing a hissing sound. Look to see if your Check Engine Light is on. That may indicate that there is a leak in the evaporative emissions system that is causing the hissing sound. If the light is not on, I wouldn’t worry much about the noise as I believe this is normal. If the noise seems to worsen in any way, or you begin to notice drivability concerns, have a local expert, like one from YourMechanic, diagnose the noise in order to determine what is going on.

Annoying hissing metallic sound
ANSWER : The dealer is correct to say it is the brakes. The noise is mostly due to the material in the brake pads. The metal in the brake pads can cause a scrapping noise, then changes with temperature and will not go away with the pads that were installed.

There may be aftermarket pads on the market that can reduce or eliminate the noise for you. You will have to talk to a local parts store to see what options are on the market for your vehicle.

You can then replace the pads and rotors with the aftermarket ones. The only thing is do not be surprised if they have some noise also, although they may have less noise.

While I’m driving, my vehicle makes a hissing noise when it shifts, it will go away sometimes.
ANSWER : Hello. If the noise occurs right before the transmission shifts, then it can be caused by a few things. Depending on how it sounds, it can be a loose belt that is slipping when the vehicle is getting ready to shift. If the belt is tight, then the noise may be coming from the transmission itself. It may be low fluid or it can be a bad thrust bearing in the transmission. I have also seen clogged vents on transmissions cause this. Most of the time though it is a bad internal bearing. This is something that you should have a transmission specialist check out.

Carbon canister making a loud hissing noise.
ANSWER : Hi there. The loud hissing noise could be caused by a split vacuum hose or a loose hose. Follow the hiss to make sure it is the canister and not a separate hose. The code stored for the Check Engine Light would not be affected by a leak at the canister because it would have leaked to bank 1 and bank 2 setting a code for each. I strongly suggest having a qualified technician perform an inspection to avoid replacing unnecessary parts. YourMechanic has several available technicians that can assist you with a Check Engine Light inspection and can conduct a diagnostic on the hissing noise so that this can be addressed appropriately.

AC makes hissing noise on a 2000 Dodge Durango
ANSWER : If it’s actually hissing, it must have a pretty big leak. You can try adding some refrigerant and it might work. But, if it’s hissing, it’s not going to last long because it has a pretty big leak there. Knowing Dodges, it is generally the evaporator that starts to leak because they make them cheap. They cost a fortune to replace on that thing unfortunately. But first, try to add some coolant and see if that helps out.

Popping noise while shifting manually on a 2004 Volvo XE 90
ANSWER : Leave it alone. That’s a Volvo. I’m amazed it still shifts decently as old as it is. Because they have horrible automatic transmissions. I would just say leave it alone and don’t ever mess with manual shifting on a Volvo. That’s an old system and you can break something. Then when you find out that’s 4-5,000 dollars to rebuild the transmission, you are not going to be happy camper. If this becomes a bigger problem, you may want to enlist the help of a professional, such as one from YourMechanic, to inspect your shifting issue and let you know exactly what needs repair.