Up here in snow country, without backing plates the first time the brakes are applied after driving down a snow covered road there is little to no stopping power until the snow melts out of there. I know this because a driver was complaining about intermittent brake loss. So I crawled under there and found the rear backing plates had rusted off. After replacing them the problem was gone.
Down here in the deep south snow of course is not an issue. We have a mix of on and off backing plates and I have noticed no difference in wear between the two. The buses run on both paved and unpaved roads. Personaly I like not having the backing plates due to the easy of inspection.
I used to be a "no backing plate" guy, but the last 60 air brake buses came with them and these buses have had the best brake mileage I've seen in 28 years of doing this. It may be because a lot of the crap stays out?? Maybe it's the Meritor lining.
My mechanics don't have any problems inspecting the lining or the drums, but they can lift them high enough to walk under them also...FWIW
State spec here that we have to have them. I would rather not as they are a pain in the butt. We replace them when the rust out. They hold the heat in the brake area. In 2005 we were cooking brake linings on some buses with aggressive drivers with the old MA202 brake linings. Just baking the resin right out of the shoes (we called them fuzzy brakes). International and I believe Bendix or Meritor sent some engineers down to inspect our problems. First thing they recommended was remove backing plates. Unfortunatly not an option here.
Quick poll on air brake backing plates
Posted - 07/30/2014 : 03:47:01 AM
