ZX1100F1

The reason that GM went back to drums in the 1500 series Silverado's is that many consumers complained that the disk/disk system was a bit too touchy in certain conditions, most 1/2 ton trucks spend much of time operated unloaded or very lightly loaded, the disk brakes had a tendency to easily lock-up during panic stopping and the ABS and DRP systems were often at odds to compensate this.

To achieve a better balanced braking system engineers went large rear drums in the rear, in tests a lightly loaded Silverado 1500 will stop in a shorter distance then the previous rear disk brake models.


The Vortec Max wit the NHT Max Tow Package has rear disks to enable a higher maximum tow rating (10,500lbs) it was determined that buyers wanting this option were more likely to operate in heavier loaded conditions.

Reynolds357

This is my first post here. I hate to sound rude right off the bat, but the guy at the dealership flat lied to you. If GM can make a front rotor that will not warp, they can make a rear one as well. If what he told you was true, they would have had to go back to 4 wheel drum. I think the truth is they wanted to save money. I have never really figured out how it is cheper to build drum brakes than disc, but the engineers say it is.
It has also been speculated that they made the change to smooth out the braking of the vehicles. I guess that is possible, but I would think Ford's fix for that problem was a much better fix. Ford went to a rear pad that had app. 40% of the area of the front pads. Ford's "fix" makes more sense to me than GM's "fix." That is why I lean toward believing it was for cost savings.
Having said that, I have no problem with rear drum brakes. They work just fine. With the new transmissions in the trucks, you should be doing most of you extended brakeing with the engine when pulling heavy loads. Extended, not short, braking is what builds up heat in drums. If you drive properly, that will not be an issue.