Grinding sound that replacing brakes didnt fix

I have a 1998 Ford Taurus and In December 09 I had my brake pads and roters replaced because they were making a metal on metal sound. The work fixed the sound and for a couple of weeks the sound was gone. Then the grinding came back but it wasnt doing it everytime I used the brakes. I felt stupid when it only happened once in a while but I called same mechanic who took car said he couldnt find anything wrong with it but the pads werent lining up with the rotors or something and he drove around with the e brake on for awhile and it should be fixed. Nope. The sound was there and kept getting worse and was now consistently annoying everytime I used the brakes. Again, called mechanic who gaurantees his work and asked him to look again. This time he said the brake pads were all cracked! So he replaced them since they were still under warranty and that should fix sound. Nope. Still making annoying metal on metal sound so again…mechanic took the car and checked brakes said small spot on pads werent lining up flat with rotors for he had rotors machined and bled lines of any air and it shouldnt make that sound… Guess what? It still makes that annoying sound and now its with a vengance. Sounds like something is rubbing as the tires rotate. I will not be taking the car back to that same mechanic,guarantee or not. He obviously either needs a hearing aid or doesnt know what the problem is and has too much pride to say so. What can I do? I couldnt even sell the car as is with this sound.

You may have a worn wheel bearing.

Like you want, get another opinion.

Could the noise be coming from the rear? I had something similar with my '01 Taurus, but it turned out it was just a build of brake dust in the rear drums. A quick cleanout cured the problem.

That should be “build up” of brake dust…

Yes it is coming from what sounds like the right rear side. How do you cleanout a brake drum? Will it require someone to completely take apart the braking system or is it something I can do myself?

Simply remove the wheel and drum (you may have to back off the brake shoes to do that) and dump out any dust you find in it. Wipe it out with a rag and replace it. Might just do the trick.