I have a 2008 Accord with 24,000 miles and have been told the back brake pads need to be replaced. When I called my dealer, I was told that Honda knew there was a problem but did not know what was causing the excessive wear. Honda will only assit clients with less than 20,000 miles. I am being asked to pay to have the pads replaced with no diagnosis of the problem. Anyone have any additional info or assistance?

Take the wheels off and look at the calipers. If there is 1/8 of an inch or less of pad, it is time to replace the pads.

First, brake pad life depends on your driving style. Drive hard, brake a lot and the pads won't last a long time. Second, the material of the pads can affect life too.
It wouldn't hurt to ask the dealership about the service bulletin on your car. If you are a DIY person, you could take it apart and inspect the pads/rotors and scuff them up a bit. I've fixed some minor annoying issues by doing that. Sometimes your pads can get glazed over, and I've had weird little bumps on my rotors that made a horrible grinding noise when coming to a stop. Used my grinder and cleaned/sanded the surface and it hasn't come back in 2 yrs.

This tutorial will help you : http://www.ehow.com/how_4719219_off-brake-rotors.html
Some after market brake pads are better than the company fitted ones, but they will be more costly.

I had a car with rear disk brakes, and to get caliper piston back I had to use a C-clamp to compress it. Give it a try.

The way to solve a problem with Honda auto is to never buy another one. I have a 04 CR-V and 08 accord. I have had rear brakes wear out with less than 30000 miles on accord and the battery won't hold up as it keeps going dead, The CR-V A/C went out and the dealer told me it would cost $3,000 plus to fix. Honda dealerships have convinced me that I should never again buy a Honda as they will not stand behind their warranty
. I would never recommend a Honda to anyone unless they are my enemy.

no, 12mm wrench or ratchet on 12mm socket. the piston is tough to push back in. its a twist in type and you will need some force to push and twist the piston back in. - note rear brake pads wearing out on the new 08-09 accords are very common and if under 16-18 thousand miles it may be covered. honda knows about this problem

Brakes need replacing. Just take the wheel off and have a look see.

from my experience its sounds like ur front rotors may need resurfaceing...if ur doing that...may as well replace the brakes on the front as well...sometimes glazed front brake pads may make a sound but never heard of it as a grind, usually its a squeal...have ur dealer check ur rotors for hot spots in which u would need them replaced if they are overheated..also check the front pads for cracked brake pad material

Your rear brake pads are most likely worn to the wear indicator which can make a high pitch squealing noise. It is very common that it will squeal when backing up, but not when applying the brakes. 50,000 miles is about the average life for rear brake pads on your car.