2016 CX-5 "Whistle Type Noise" after brake pedal is depressed

I bought my 2016 cx-5 back in January and after driving it I noticed a "quick squeak or air releasing noise" when I take my foot off the brake.

This video (at 5 secs) was taken back when I got the car but it has gotten louder and more annoying. When I press the brake slowly down I can hear a spring clicking and releases when I lift off the brake.

While driving and letting off the brake it follows by a quick high pitch noise. It is def something from behind the brake and my friend said he's pretty sure it's coming from the brake booster (#1 in the picture).

The video attached is old and if there wasn't a snow storm now I'd get another lol. The picture is what I think is wrong but can that mean this part is bad and can cause a issue?

I took it to Mazda who said they don't hear anything and it's normal for Mazda. I asked to get into other cars to see if they all do that and none of the others did. Mostly this is just extremely annoying as I drive to work 6am and like quiet and all I hear is the "squeak" noise lol.

Sorry for the long and probably confusing question but any insight would be really appreciated. Anyone else have something similar? Thanks so much!
 

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I bought my 2016 cx-5 back in January and after driving it I noticed a "quick squeak or air releasing noise" when I take my foot off the brake.

This video (at 5 secs) was taken back when I got the car but it has gotten louder and more annoying. When I press the brake slowly down I can hear a spring clicking and releases when I lift off the brake.

While driving and letting off the brake it follows by a quick high pitch noise. It is def something from behind the brake and my friend said he's pretty sure it's coming from the brake booster (#1 in the picture).

The video attached is old and if there wasn't a snow storm now I'd get another lol. The picture is what I think is wrong but can that mean this part is bad and can cause a issue?

I took it to Mazda who said they don't hear anything and it's normal for Mazda. I asked to get into other cars to see if they all do that and none of the others did. Mostly this is just extremely annoying as I drive to work 6am and like quiet and all I hear is the "squeak" noise lol.

Sorry for the long and probably confusing question but any insight would be really appreciated. Anyone else have something similar? Thanks so much!
From the video did you pump the brake pedal repeatedly or just keep pressing the brake pedal down? The best is you show the foot action pressing the brake pedal while recording the noise. With such loud noise it’s hard to believe the tech at Mazda dealer couldn’t hear it and declared your brake is normal.

And have you lost any braking power comparing to the beginning when you just got the CX-5? If you don’t, the power brake booster may be fine.

No matter, you really want to fix this brake problem.
 
From the video did you pump the brake pedal repeatedly or just keep pressing the brake pedal down? The best is you show the foot action pressing the brake pedal while recording the noise. With such loud noise it’s hard to believe the tech at Mazda dealer couldn’t hear it and declared your brake is normal.

And have you lost any braking power comparing to the beginning when you just got the CX-5? If you don’t, the power brake booster may be fine.

No matter, you really want to fix this brake problem.
I will get another video during the day so the sound can be seen with my foot depressing the pedal. Thank you.
 
@AVSJay , I don't think it sounds abnormal (to me). The sound I'm hearing is just the air flowing in and out of the brake shaft plunger.

cx5 brake pedal plunger.png


For comparison, here is a quick video of my 2016.5 brake pedal in action ....



Video clip of brake pedal plunger noise for comparison

I wonder, if yours is louder, could there be some kind of dirt or debris stuck in whatever the venting mechanism is for that plunger bellows. It has to let air flow in and out as that push rod moves.
 
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@AVSJay , I don't think it sounds abnormal (to me). The sound I'm hearing is just the air flowing in and out of the brake shaft plunger.

View attachment 233957

For comparison, here is a quick video of my 2016.5 brake pedal in action ....



Video clip of brake pedal plunger noise for comparison

I wonder, if yours is louder, could there be some kind of dirt or debris stuck in whatever the venting mechanism is for that plunger bellows. It has to let air flow in and out as that push rod moves.
Thanks for the video. I get more of like a “high pitch whoop” or something I don’t have a word for at the end. I made another video which may be better, I am highly sensitive to sound apparently lol


 
Yes, @AVSJay with your second video clip, I can hear a difference from mine. I wonder if something is blocking the airflow on your bellows? Have you looked up under there to see if anything is amiss?
 
Yes, @AVSJay with your second video clip, I can hear a difference from mine. I wonder if something is blocking the airflow on your bellows? Have you looked up under there to see if anything is amiss?
Honestly I have no idea, my friend looked so has more knowledge and said it’s coming from inside that booster part or a spring from under the rubber covering possibly.

mazda said they hear nothing and it looks fine. I brought it back it 1-2 weeks after buying used. It’s just annoying as I hear it every time I release the brake and I have a lot of stop signs and lights by me lol
 
Yes, @AVSJay with your second video clip, I can hear a difference from mine. I wonder if something is blocking the airflow on your bellows? Have you looked up under there to see if anything is amiss?
Took a video from the same angle you did. Maybe I’m just crazy, I have 2 friends who say they hear it and 2 people who don’t. 🙄

thanks again
 
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