I own a 2002 Chevy impala, it makes a really loud grinding sound like I'm dragging metal. I took it to my mechanic and he said it was my rear breaks. Would I need calipers rotors and break pads? My car is pretty beat up underneath there is no frame my radiator and ac are held up by a metal strap. My exhaust just fell off so I have that strapped up with copper wire. Could there possibly be another explanation as to why it sounds like that?

Too much tie wire? Exhaust dragging?

I mean, if a mechanic looked at it, I would tend to go with what he said, if you trust him.....chances are you lost a pad and it'* metal on metal cutting into a rotor.....so you definitely would need rotors and brake pads.....caliper'*? Well if it'* not leaking, I would say no....just a matter if the piston can be pushed back in, the sliders work, and the e-brake functions, and we can't tell that from our PC'*....