Intermittent Brake Vibration

[CoastyAV8R]

I have a 05 GMC Sierra 1500 that has front disc brakes and rear drums with 80,000 miles on it. I've never felt something like this before but the brakes vibrate intermittently. The pedal is firm and it usually occurs when more of a demand is put on the brakes but not all the time. I've read that some people have found that their rear drums were out of round and this caused it. Does anyone have any insight on this? I've had trucks with front discs that were warped and this doesn't necessarily feel like that.

[Carder09]

Had the same problem with my truck once, I replaced rotors, brakes and fluid and all was well. Didn't even touch the rear drums.

[lowrider]

I had this problem on my last truck, an '06 GMC with rear drums. The dealer was never able to fix it.

 

Lou

[CoastyAV8R]

I had this problem on my last truck, an '06 GMC with rear drums. The dealer was never able to fix it.

 

Lou

Thanks guys, I inspected everything and the only problem I found was that the right front brake caliper was dragging on the brakes. The pads are shot as well so I"m going to put new pads and rotors on and then bleed the brake system and see how she does.

[Jsdirt]

I've had this issue since my truck had 47 miles on it. Dealer "fixed" 3 separate times, always comes back. Brand new drums didn't fix it. Turning the rotors helped for about 2 weeks, then back to square one. I gave up.

 

I heard somewhere that it could be an ABS issue ... and if so that would explain why multiple drum/rotor turnings never helped. I still give up. Price we pay for "progress" I guess ...