Something wrong with my rear brakes...

hey guys, my rear brakes used to make a really loud sound whenever i would be backing up and my ebrake wouldn’t even work that well and when i pull it up, it won’t lock the rear tires.

Anyways i got the brake pads and rear rotors changed and it still seems to be the same except it doesn’t make a loud sound anymore. My rear brakes still take quite a while to engage when i quickly pull it up, and it still won’t lock up the rear wheels. Pretty much, it won’t even slow the car down… it’s almost like it’s not working. We tightened the ebrake but it still does not seem to help much…

Does anyone here know what could be wrong with my brakes?

Btw it’s a 1992 240sx with ABS. But the ABS fuse has been taken out.

Most likely one or both of the ebrake mechanisims on the calipers are siezed.