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.

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.

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

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.

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.

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

2011 Silverado braking vibrates during downhill

97chevor
Explorer
Aug 31, 2016
I always run downhill in a lower gear. Low enough that truck doesn't speed up off throttle.
marspec
Explorer
Aug 31, 2016
My F450 did the same thing. Heavy braking downhill or sometimes level ground caused vibration. Not towing no vibration. Took to dealer. Problem was in front end, not the brakes.
whosgreg
Explorer
Aug 31, 2016
Campfire Time wrote:
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.

When I push the BC button, the trailer slows down and I know it's working. The number on the BC shows 18. However, I am suspecting that when I apply the truck brakes, I don't feel the trailer brakes being applied. I would assume that the trailer brakes and truck brakes would be applied equally??
hawkeye-08
Explorer III
Aug 30, 2016
Campfire Time wrote:
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.

Some more reading can be found at Not warped rotors
Campfire_Time
Explorer
Aug 30, 2016
JustLabs wrote:
As inexpensive as new rotors are, people are still getting old rotors turned?

I've been told places like AutoZone do turn them. I usually don't have them turned so long as the surface is fairly smooth and isn't gouged. Once they start really wearing down I just get new ones.

As far as cost, it's like $12 bucks to turn them. The set of rotors I just put on my Sierra in spring were $45 each. So there is a bit of savings to turn them, mine are usually to far gone to turn them.
whosgreg
Explorer
Aug 30, 2016
Thank you all for your advises. I will check them out and see what I can find.

When I push the BC button, the trailer slows down and I know it's working. The number on the BC shows 18. However, I am suspecting that when I apply the truck brakes, I don't feel the trailer brakes being applied. I would assume that the trailer brakes and truck brakes would be applied equally??
JustLabs
Explorer
Aug 30, 2016
As inexpensive as new rotors are, people are still getting old rotors turned?
Community Alumni
Aug 30, 2016
Campfire Time wrote:
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.

x3. I would get the rotors turned to remove the deposits, some new pads, and bed them in correctly. Also don't depend so much on the trucks brakes when descending. Let the transmission and the trailer do the majority of the job for you. Also, watch your speed at the top of the hill so that you can more easily control your speed on the way down.
larry_barnhart
Explorer
Aug 30, 2016
no issues using our GM brakes. Really don't use the truck brakes going down a mountain. Our 2001 8.1 going North on the I-5 grapevine did over heat the brakes and caused the steering wheel to shake but it was drive error on my part starting too fast at the top. Just not thinking. The allison was new to me.

chevman
Shadow_Catcher
Explorer
Aug 30, 2016
My experience and research I did is that rotors seldom warp, however certain pads will deposit bits and pieces of themselves. It was a matter of finding the right pads.