Can someone here help me identify what is going on with my truck. 2021 f150 , 55k miles, purchased new. Hearing it when slowing down or backing up driveway. Frustrated as ford service department keeps the vehicle for days, says we can't replicate and returns it. I hear the sound literally pulling out of the dealer and driving home. Even took the tech for a spin and he heard it and they lubed the calipers and said they could not replicate it. It's TSB 21-2253 this issue or something else. Going to bring it up today with them.

https://youtube.com/shorts/RqmSsV28Ty8?si=5Esk7AmGoJm5Fq_C

 

Maybe it's this SSM I attached. Without your VIN I can't verify your vehicle is equipped with these EPB calipers.
Hopefully that helps

 

My truck is making the exact same sound. Did you ever find out what it was? I have not taken to the dealer yet but yeah they are trained to say they can’t hear it. I will go from 1 to 10 in about 5 min if they play this game. I haven’t had this truck 9 days and this crap is happening.