2011 Silverado braking vibrates during downhill

[whosgreg]

Hi fellow RVers,

For the 3rd time, going downhill in the mountains, the brakes vibrate. I had to manually use the BC instead of the truck brakes. Tires are brand new. Brake pads are good.

Without the trailer, the brakes don't vibrate downhill. Wonder if I'm setting up the BC wrong because when I manually apply the BC and truck brakes the same time, the brakes didn't seem to be vibrating as much.

Any help would be appreciated.

[aguablanco]

I have this exact same issue with my 2012 Chevy. Just had the oil changed and tires rotated after a 2500 mile trip and while the wheels were off I personally inspected the front rotors pads & calipers. They were perfect in all regards. I did not use a dial indicator to check for warp but I did spin them and saw no visible warp. I have come to suspect that this issue is caused by the ABS system. Anyone agree?
RichH

[Campfire_Time]

It is not warped rotors. True rotor warp is very rare. If it was warped rotors you'd get the pulsation all the time at all speeds.

It's hardened pad material stuck to the rotors. And yes it's caused from heat. Moreover it's caused from improper bedding of the pads, or lack of, after installation. Especially with ceramic pads. After it happens pull over and look at the rotors. You'll see little comet like deposits. It's more prevalent with ceramic pads but can happen with any type of pad. Thickness of pads is not an indicator that this will or will not happen.

I'd put new pads on before doing anything else. And readjusting the BC would not hurt either.

[turbojimmy]

Yes, no one makes decent rotors anymore. Even the GM parts are made in China. They warp from heat almost immediately. The new-ish rotors on my Avalanche are okay until they get hot - like slowing down from highway speeds. Yours are vibrating because they're getting hot slowing the trailer down. I hate to say it's normal, but it sort of is these days. At least on GM products.

[trail-explorer]

Warped rotor(s) cause(s) brakes to vibrate.

[donn0128]

Overheated and now warped brake caliper. Sort of common on GM products. I suspect your riding the brakes? Instead, brake hard to get below your desired speed and get off the brakes. Riding the brakes overheats everything.