... but your brake question:
-Did you check your the caliper? Any leaks?
-Is the disk discolored?
-Are the pads good?
-Is the disk under size (pronounced ridge on the outer edge)?
-Have the rear calipers ever been replaced?
-Have the rear brake lines ever been replaced?
You could try using the brake pads and squeezed them back into the caliper. You actually don't have to remove the pads to do this. Try it several times. This cleans and lubes the caliper puck/piston.
If the rear calipers have never been done, 27 years is a long time for brakes.
Let us know ....
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)