pbcdb

When I back up and apply my brakes I hear a hum come from the rear drivers side wheel. This hum sound is also present when my car is rolling backwards, sometimes. Also my rear wheels do not spin freely with the parking brake off. Now I know I need new pads and I think the rotors are warped and need to be machined cause they have a layer of the gloss on them. But I am wondering if the calipers might be bad. Is there a way to check the calipers or would warped rotors and worn pads cause this sound. to give a better example of a hum is it kinda the same sound that some semis/big trucks make when they stop and it is also kinda sounds like my old bike brakes when I slammed them on. I know shitty examples but thats the best I could come up with.

pbcdb

bump

BatuKing

If you have disks in the rear check the slides make sure they go in and out with out much resistance. Also make sure their lubed ( synthetic brake grease). then check your parking brake cable play according to the helm.

IF they are drums make sure you check the clearance between the pads and the drum if its too loose or tight you will have problems