I just rebuilt my drums (shoes, drums, self adjusters etc etc) and took the car out for a burn. I hit the brakes while reversing to set the self adjusters and then did a few hard stops to check the braking power. As i drove at higher speeds, I noticed when i applied the brakes that there was a small amount of vibration in the pedal. Are my drums...warped? I don't think a few hard stops should be enough to warp brand new drums. I set my e brake before I went out, and when I got back I noticed that it wasn't grabbing very well at all. What's the deal? Did I just overheat the **** and **** it all up? Any ideas will be greatly appreciated.

Cheers!