On my E350 15 psgr. Had them checked by a reputable mechanic. Said everything was great. Cleaned them out, but not much else needed. When I begin to depress the brake, they generate an ear-piercing squeel. Not metal to metal like the shoes were worn (which they weren't ) Sounded like wear indicators but the mech didn't seem to think anything was wrong.

Any suggestions on what to look for to silence that squeel? Everyone looks at us when we pull up to a stop

 

the shoes could be glazed over making that squeel. inspect the front brakes also.

 

Fronts are A-Ok (did them myself). Glazing. Hmmm. Could very well be although the mech pulled the drum, cleaned out the dust etc. Didn't mention anything about that.

How do you un-glaze the shoes?

 

you put new ones on. make sure its a good quality shoe. and put plenty of grease on the contact points on the backing plate.