I have a 99 Civic HX with 74k miles. I have replaced the front brakes a
couple times (watch out for Raybestos QuietStop!) but the rear drums have
never been touched.

Recently I started noticing brake squeal in the rear when backing down my
steep driveway in the morning. I didn't notice under normal driving and
braking, so I ignored it. After a few more weeks or so, I started to hear
more of an intermittent scraping sound when braking in reverse. At this
point I became concerned that the pads had worn down & were damaging the
drum.

After a few days or so I bought some new brake shoes and popped open the
drums. Not only did everything look fine, but the old shoes looked like
they were only 50% worn; there was really no apparent use in replacing
them. The inner drum surfaces were smooth, as were the shoes.

The brakes seem to be operating just fine; I use the e-brake every day.
In forward motion the ebrake works effectively; the front discs squeal a
little when cold (standard Raybestos organic pads), otherwise I don't
notice anything. Does anyone have an idea what might cause these strange
sounds? Again I only notice it in reverse, and if I pulse the brakes a
few times it will start to go away.

thanks,
Cooper