I've had my rear drum cylinders changed three times and as soon as I brake one-two times they break. So now the rear drums don't put in much of the work braking the car. So, I have to change my front brake pads frequently because they do all the work to stop the vehicle. I just changed my front pads this week and two days into them they are already starting to screech. These replacements are all OEM AC Delco parts.