Brake pedal chirp

[bodabdan]

I am clueless on this one. 2005 LT Burb, 225k miles, all stock except 2" RC lift.
I have an intermittent chirping noise that's related to applying/releasing the foot brake.
The noise is not a mechanical noise, it's an electronic type chirp. It's coming from somewhere in the center of the dash, forward of the center console. Sometimes it makes a double or triple chirp. Link to videos below.
It usually happens at low speeds, and 75% of the time the brake pedal is a factor. The other 25% just happens whenever, but always at low speeds (<10mph).
I do have an issue with the adjustable pedals not moving. They are in the rearward position (short leg mode). They will try to move but there's either a geartrain issue or a limit switch issue, they just bump and stop. Not sure if that's a factor or not.
Any insight on this is appreciated, thanks.

 

[dps01]

have not experienced this, however:

1. Has any work been done on your vehicle recently?
2. When did it first occur?
3. Does it occur regardless of steering wheel position?
4. Is there an aftermarket audio system and if so, does the noise come from the location of the chime module?

Just trying to narrow potential culprits…

 

[Doubeleive]

I am clueless on this one. 2005 LT Burb, 225k miles, all stock except 2" RC lift.
I have an intermittent chirping noise that's related to applying/releasing the foot brake.
The noise is not a mechanical noise, it's an electronic type chirp. It's coming from somewhere in the center of the dash, forward of the center console. Sometimes it makes a double or triple chirp. Link to videos below.
It usually happens at low speeds, and 75% of the time the brake pedal is a factor. The other 25% just happens whenever, but always at low speeds (<10mph).
I do have an issue with the adjustable pedals not moving. They are in the rearward position (short leg mode). They will try to move but there's either a geartrain issue or a limit switch issue, they just bump and stop. Not sure if that's a factor or not.
Any insight on this is appreciated, thanks.

what kind of 3rd party (non oem) stuff is installed in the vehicle? sure doesn't sound like anything normal
is there a alarm? brake controller? anything not oem?

 

[nonickatall]

As far as the chirping noise is concerned, I would actually guess it's the V-belt or some bearing that's chirping. The fact that this increases when the brakes are applied, has to do with the fact, that the servo pump then has to generate more pressure for the hydro boost.

So I would first look at whether the chirping is coming from the belt drive. Such noises can spread throughout the car so that you think they are coming from inside.

As far as the adjustable pedal is concerned, I would try to keep moving it back and forth. Sometimes the motors get stuck and especially if they haven't been used for a long time.

That's what happened with my seat motors, only after a long time back and forth and back and forth solved at some point.

That's just one possibility. When you operate the pedals, put your head in the footwell and listen for a slight click.

 

[bodabdan]

what kind of 3rd party (non oem) stuff is installed in the vehicle? sure doesn't sound like anything normal
is there a alarm? brake controller? anything not oem?

Stock everything except for the RC 2" torsion key lift and rear coil 3/4" spacers.. Radio, tint, mirrors, lights all stock, no brake controllers, no tuner, no CAI, no mods whatsoever.

 

[Doubeleive]

Stock everything except for the RC 2" torsion key lift and rear coil 3/4" spacers.. Radio, tint, mirrors, lights all stock, no brake controllers, no tuner, no CAI, no mods whatsoever.

weird, in the video it sounds like a electronic chirp. do you think it is electronic or metal on metal?

 

[bodabdan]

As far as the chirping noise is concerned, I would actually guess it's the V-belt or some bearing that's chirping. The fact that this increases when the brakes are applied, has to do with the fact, that the servo pump then has to generate more pressure for the hydro boost.

So I would first look at whether the chirping is coming from the belt drive. Such noises can spread throughout the car so that you think they are coming from inside.

As far as the adjustable pedal is concerned, I would try to keep moving it back and forth. Sometimes the motors get stuck and especially if they haven't been used for a long time.

That's what happened with my seat motors, only after a long time back and forth and back and forth solved at some point.

That's just one possibility. When you operate the pedals, put your head in the footwell and listen for a slight click.

I'm an old wrench turner that's worked on a ton of stuff over the years, I'm certain that this is not a mechanical noise like cavitation or belt noise or bearings. It has new ribbed belts and good clean accessory pulleys, idlers, etc..
The noise is the exact same frequency and duration every time, the only variable is how many chirps, but always between 1 and 4.
I've had a friend listen for the noise outside of the vehicle and it can only be heard from the interior.
As far as the pedals, I can feel the servomotor bump, it just stops immediately, as if it's in a mechanical bind like a bad plastic gear or possibly a limit switch is hung up or out of adjustment. I just need to pull the pedals out and get them on the bench but I don't do well with working under the dash with a bad back so I'm putting that off for now. I only mentioned it here in case there's some way it's a factor in the chirp.
I appreciate the input. Thanks!

 

[Doubeleive]

Stock everything except for the RC 2" torsion key lift and rear coil 3/4" spacers.. Radio, tint, mirrors, lights all stock, no brake controllers, no tuner, no CAI, no mods whatsoever.

the adjustable pedal motors have been known to stop working but the chirp noise is pretty unusuall.
I initially was thinking from your title that you were getting brake pedal noise which is usally resolved with a little lithium grease