On certain models the rear brakes can groan when coming to a stop. Replacing the rear brake drums may be necessary to correct this issue.Google+
Car Problem Reports
Honda Odyssey Rear Brakes May Groan Due to Faulty Rear Brake Drum
Honda Odyssey Problem
Visitor, 2000 Honda Odyssey, 156,700 mi
Noise just starting occurring last winter ,but noticed it mainly occurred during dry weather days after rain/snow. It comes and goes. I haven't heard it for months and just now was traveling through a stop and go traffic in the city and the drums starting groaning bad - but I could control it from going off by braking slowly - stopping suddenly the whole van felt like it vibrated. husband replaced rear drum pads and everything looks normal - but now looking to drop off at dealership since van is due fo r state inspection.