Abnormal noise (whistle/hissing) under the brake pedal while pushing it.

[Abdulla Muhsen]

Hi All,

In my GMC truck 1500 Sierra, it makes an abnormal noise  under the  brake pedal area while pressing it. The sound comes directly from interior and its like a whistle sound and called sometime a hissing noise. The brake system functions properly and without any defects except the mentioned noise.

Is it possible from the brake booster? or could be from other sources?

 

Appreciate sharing your experience feedback in this problem.

 

Regards,

 

Abdulla

brake gmc.xspf

Edited April 26, 2023 by Abdulla Muhsen
added more details about the problem

[Cody Mowdy]

My 2015 Silverado has recently been making this noise as well. I assumed it has to do with the brake booster. Like you said it functions correctly except makes a funny almost screeching noise when pushing on the brake initially. Does yours make the noise all the time? I noticed it happening to mine when first pressing the brake prior to starting the truck. 

[m3n00b]

My 2016 does the same thing.  I reported it to the dealer a few times and all they did was lube the linkage.   Never fixed it.   It mostly happens when you have to hit the brakes pretty suddenly.