This involves the emergency brake that will not hold the vehicle when applied. i had noticed that the emergency brake did not do a very good job holding the vehicle when applied from the time it was new but had not given it much thought since i never used it. several years later i tried to get it inspected and it failed. i found that the rear emergency brake that ii never use were had worn out shoes and had damaged the drum. i replaced the shoes and one drum and was able to get the brakes to hold when the brake were applied. the brake has been applied properly sense then but started to do the same thing again by not holding the vehicle. i had to replace the shoes again at 172,000 miles. this seems to be a problem with this vehicle that general motors will not address. *tr