I have a 2016 Chevy Impala LT. when I brake it sounds like an old rusty mattress. Not sure if it’s a brake issue or a suspension issue. Any thoughts?

 

Welcome Rowdy - can you tell if it's coming from front or back; right or left side? May help to have someone drive while you sit in different seats. If it's a constant sound as long as the brake is pushed, likely brake and not suspension

 

bounce it when it's parked

 

Hmm, it sounds like your Chevy Impala's braking noise could be due to a suspension issue. I'd recommend taking it to a trusted mechanic.