alyssayk33

Hello! Just got a brand new 2022 lexus ES300H. The car is beautiful and amazing! But this buzzing noise from hydraulic brake system is driving me crazy! It makes buzzing nosie whenever I brake to complete stop. I looked up online and some people say it’s normal but some say it shouldn’t make that noise nearly every time I hit brake. I understand that it’s the sound that it makes when it’s repressurizing its hydraulic brake system or whatever, but it bothers me becuase it makes the noise pretty often!!

I took it to the dealer and we went on a ride with the mechanic. He said it’s normal and I woukd hear the noise all the times. But some of my colleagues who has toyota rav4 hybrid told me that they don’t hear anything when they brake!

Does everyone who has ES300H really hear this buzzing noise every 2nd or 3rd time you hit brake to stop? But I don’t hear the noise from youtube videos where they test drive ES300H… Ugh, it bothers me so much and I paid a lot of money for this car!!

dezymond

Mine doesn't make that noise each time I brake, how hard are you braking?

alyssayk33

Not hard at all. Even when I brake really soft and smooth, it sometimes buzz when the car comes to complete stop.

Original dealer where I just bought my car told me it was normal… of course it didn’t buzz too many times when I was driving with the mechanic. Should I try going to different dealer?

Forceman

I have a 2022 ES300h. I have never noticed any noise while breaking. Tkae to the dealer and insist to have something done.

LS500Fan

My hybrid makes so many noises like that I don't even care anymore. It makes noises when I brake, when I open the door to get in, when the car has been sitting for hours, etc. This must be your first hybrid because I've driven two Prius and a RAV4 Prime over the course of 8 years before getting my 300h. If you haven't had a hybrid before this might be concerning but it's nothing to worry about at all. It's 100% normal and is mentioned in your owners manual. Do not bother any more dealers about this you can't compare your braking system to the RAV4 to be fair (I have both RAV4 hybrid and ES hybrid in the garage currently).

ESh

Mine makes the same noise when I open the drivers door, when I drive and brake but not everytime...normal. All hybrids do that.

It's the brake actuator.

LS500Fan

If you want a more technical explanation, basically all power brake systems have a brake "booster" that makes braking easier. Some systems use power steering fluid hydraulic pressure to boost your brakes (hydroboost, not very common). However, most use engine vacuum (common for decades). Even newer stuff with turbos and hybrid applications use a dedicated vacuum pump to provide vacuum to operate the brake booster and give you easier (and safer) braking.

What you and others are hearing is the electric vacuum booster system. It runs for a few seconds to increase vacuum so your brakes stop you well. As the vacuum is used up from braking, the car's computer needs to command that pump on to increase vacuum again for your next brake application.

Again this is totally normal and not an issue on any Toyota or Lexus hybrid and other makes/models/engine configs as well. Normal non-turbo gas engines typically do not have this system. I'm trying to keep things simple here, I realize there are exceptions and the system is more complex than I'm explaining here.

To be honest the reason you probably hear it so much is because the ESh is so incredibly quiet in EV mode, and it's in EV mode quite often while braking. When my car is silent (radio off) and "idling" at a stop I hear the battery fan under the back seat and wish it was quieter. But that's another topic LOL

E46CT

As someone who's had a Prius, a CT200H F Sport, another CT200h F Sport, a 2021 ESh and now a second 2021 ESh, as I've posted for years on this forum, the noise is extremely normal and extremely common. The brake pressure is being helped by electric motor since there's no engine that's always on. So the car pre pressurizes when you open the door knowing you're likely going to drive.

Don't worry, enjoy your car! Your 7ES will likely make other annoying noises you will have to worry about which I've documented and fixed as world's firsts on this forum! Good luck.

Forceman

So, my car is the only one that does not have any noise? Its odd. Could be that my ultra lux model make the difference?

alyssayk33

See, some people say it’s normal and some others say they don’t hear it at all. I have luxury model as well and I feel like that shouldn’t matter. I just feel like it’s normal sound, however, it shouldn’t make the noise so often like mine. Not sure what to do, especially when dealer is telling me it’s normal😥

Forceman

Can you go to the dealer and try one at the lot and see if it has any noise. If not, you have a case.

LS500Fan

It’s normal, don’t waste the dealers time. Maybe some people don’t hear the noise because they are older with not so good hearing??

alyssayk33

From my understanding, the car makes noise when it needs to pressurize the brake system. But does it need to pressurize every couple times I brake? I don’t even brake that hard, it makes the noise even if I brake very soft and gradually. I totally understand the sound is normal, but I thought it should only make the noise after braking several times and using up the pressures.

It’s just odd to me that I don’t hear it on any of the Youtube videos of people test driving the same car. I even hear the electric sound of the car, but not the buzzing sound in the videos. I also don’t recall hearing the buzzing noise when I test drove an ES300H (I test drove their loaner car becuase they didn’t have enough inventory when I was first shopping).

I love my ES300h, but this noise is the only thing that still bothers me. I honestly think this would be my forever car if it didn’t make this noise every time I brake. I’m hoping I would get used to it soon.

LS500Fan

Negative pressure sure, it's vacuum, technically. It's all controlled automatically using sensors so there's no set thing that says it should only run every second or third braking, it runs and increases vacuum as needed. Two different cars may run more or less but it's all based on the same parameters in the computer. I may press the brake pedal more slowly and not as deep during my stops because I coast down slower and stop more gently. So I may use more or less brake assist vacuum than you. There's no way to control that, and it's there for your safety.

I suppose in theory you could disconnect the vacuum pump by disconnecting the wiring or cutting some wires, but it would cause your brake pedal to be extremely stiff and unsafe, and would likely trigger all kinds of warning lights and messages.

You may hear the brake buzzing less if you have the window down a bit or the sunroof open a bit to bring in more outside noise. The interior with the windows closed is staggeringly quiet, much quieter than my Teslas in fact. Maybe you should consider driving with the sunroof popped up or the music/radio volume up a tad so you never really notice the brake assist pump. I've been driving hybrid for like 7-8 years so I don't even think about it now.

E46CT

ya the car needs to make sure you have brakes and are safe. so it will continually charge as needed.

too many people worry about the operation/sequence etc. the entire hybrid system is programmed to do what it needs to do with zero driver thinking. you just drive. let it do its thing =)