My 2002 GMC dually disc brakes with 90,000 wasn't stopping my camper like I felt it should or even stop itself like it should. I actually thought it had drum brakes but it had disc.
I had a GM dealer inspect them, he took off the fronts, and he said they are fine for another 30,000.
I forgot about it for a few months. I still wasn't comfortable so I then went to a actual brake and muffler shop and told them I wanted all new rotors, pads, emergency brakes, everything new on it.
The order came in so I went down and was watching the mechanic work on the rears especially. I wanted to see how the axle came out actually.
The mechanic said I already put new pads on it in the rear. I told him I was the original owner and never had any brake work done to it. We firmly disagreed on that point. He didn't call me a liar, but the thought was there.
The read pads were thick yet, maybe 3/8 of an inch and looked great. The discs looked fair but needed to be surfaced regardless. I told him to put all new stuff on anyway.
I talked to the manager and told him about the disagreement, not to get anyone in trouble, but to find out why the pads were good but the discs weren't.
He told me to hit the brakes harder more often.


That would help. I said okay, and walked away, not really understanding his theory.
A month later I talked to the GMC dealer in town and talked to the manager and posed the same question to him. He said basically the same thing as the brake guy said, and I questioned him further. He told me that the fronts do most of the stopping, which I knew, and the rears don't really get used unless there is a big load. He said if there is rust on the rears they won't get wiped clean unless I use the truck more often.
He said that unless I pull a heavy load, enough to make the rear brakes work, I need to do something more to remedy it. He said if I don't pull anything for a while to just hit the brakes hard enough to slow the truck down from 55 to about 30 a few times. That will keep the rotors sparkling clean. It seems to make sense to me because I always really babied the brakes to not wear them out and they didn't last doing that. For what it's worth.