My right front disc brake started making a squeaking noise at about 50,000 miles when I appied the brakes. It was on and off at first but became more freqent. It wasn’t a grinding noise and it wasn’t the sensors for a low pad. I changed the pads and after about 2 weeks I started getting a grinding noise when I’d apply the brakes. I checked the pads and they were fine. After a few months I replaced the pads, grinding happened again after a few weeks of wear. Within the next few months I replaced the pads again, each time trying different types. Had the rotors turned recently and again, new pads. The grinding is gone but after a few weeks the brake makes a chirping sound now when applied. They work fine in stopping the car. Any thoughts?