I will be upgrading my brakes soon but I seem to have a unique problem I'd like to sort first. After the car has been sitting for a while when you hit the brakes hard it shakes as if the rotors are warped. However, after that initial hard brake they seem to work just fine with no shake at all. Could it be uneven pad wear? I haven't taken a look yet I just thought I'd throw this out there...

Thanks

 

Could be build up on the rotors. Dirt, rust, etc. Its pretty hard to warp a rotor, and if you do, it would shake all the time not just the first time you get on them.

My Subaru shakes constantly. After looking at my rotors, they arent warped. But they have a lot of deposits on them from the pads. So Im going to have them skim cut since they're still plenty thick, and get a new set of pads.

That being said...my TA with LS1 brakes sits for months, and accumulates a decent amount of surface corrosion, and I never get any weird pulsing or shaking on the first drive. After a bit, they're all cleaned off. So...just check everything out real good, and maybe get the rotors cleaned up and new pads if you want to see if that is your issue.