I recently had the drums and shoes replaced on my 2003 cavalier, about a month later they started squealing, i took it back and they said everything looked fine, they cleaned and lubricated everything and the noise stopped, they told me if it started again they would replace everything for free, its been a few weeks now and I can barely hear the noise just not as bad as it was, but I have a feeling its going to be just like it was, any idea what would be causing this? Any help would be great, thanks