Front brakes or rear?

So I had a problem with my e-brake sticking a little while ago and I noticed that when It would barely stick, when I hit 50-60mph I would get a vibration. I fixed the e-brake sticking situation but have noticed yesterday that I had a very similar vibration and it seems to be coming from the rear brakes because when I brake, it gets much worse. I was just wondering if seems like it would be the rear because I didn't know if there was something that could cause it in the rear like the front has (like warped rotors). Thanks for any advice. I also could not find a good write up for replacing rear drum brakes if someone might know where that is located. Thanks!

 

Doesn't hurt to open up the drum so you can check drum runout and the condition of the shoes.

http://www.youtube.com/watch?v=Po-WXqIKjHQ

http://www.youtube.com/watch?v=195JUby2Uy4

 

Does the extended cab have a drive shaft support bearing like the doublecab has? If so check the rubber holding the bearing if it is shot then the driveshaft can bounce around and cause a vibration that is felt in the seat as if it is coming from the rear. If you are driving an unloaded truck most of the time you are taxing the rear brakes very little.
Pull the drums check all of the hardware and be sure nothing is broken. Adjust the shoes and try another drive. Worn shocks can also contribute to wheel hop and axle movement under braking.

 

Generally speaking if you feel the vibration in the steering wheel its the front. If you feel it in your seat, its the rear.

 

I converted to the Tundra brakes and my shake went away. Your rotors are probably warped.