brake air noise

[tonybaloney]

i noticed today that when i apply my brake, there is an air noise right before the brake engages. do any of you guys noitce this too? i know if i have air in my brake system, the air noise should come after the brake engages right? thanks!

also, the noise is almost always there if i push down the pedal quickly. the noise seems to go away if i push the pedal slower. i can pretty much reproduce the noise by pushing and releasing the pedal without having the brake engages.

 

[1MZ-V8]

I have the same noise when braking. I believe this is normal.

 

[fitzt4r]

Got it too. I assume it is normal?

 

[sharp4runr]

I've had that noise since I bought the truck. 33k later and brakes still function great Incidentally, the pads just got changed out a few hundred miles ago...

 

[Mark86]

It is definitely a nomral noise. I have heard it on every car driven.

 

[ptung07]

Yeah, I noticed this too on my 2003 4Runner. I think it is normal and by design. To me, it sounds like some kind of pressurizer for the brake systems.
For example, if you were to put the car in the On mode (without the engine running), and keep on pressing/pumping the brake pedal, no matter how many times, the brake has its "feel" as it is still able to pump as if the engine were on. You can hear the "noise" or some kind of pump sound. Maybe that is why the brake fluid container in the engine compartment is so much larger (to accommodate for the pump or generator) than the ones in my other cars.
If you were to try this with like a Toyota Corolla, Sequoia, or Lexus RX300, the pedal will stop having its "feel" after 2 or 3 pumps and then it gets harder to push down when the car is in the on position (w/o the engine on)
Just a speculation though...

 

[icantsee]

 

[SH0ck-D]

Lol. I started to freak out when I first heard the noise. I guess it's one of those things you don't notice until you actually listen to it. But my car performs well, so I am in no worry to throw the bank at fixing this problem.