So pretty much every cold start, the first time using my brakes after getting the car to move, the brakes sort of have barely any braking power makes a sound sort of like indigestion or something, and then has a little braking power once it's further depressed. This only happens ONCE after every cold start. Anyone have any idea what this is?

Also, call me a dumbass, but after hitting 120mph on the freeway at like 2AM; While trying to brake back down to the normal limit, my brake application shook the car. If I lightly applied it, I'd get a rattle from my windshield/dashboard area. If I applied it even more, but not slamming it, it'd sound like an earthquake inside the car. There's braking power but the vibration of the dashboard and everything was so loud that I felt if I braked anymore, my car might fall apart. I know speeding at 120mph is a stupid thing to do, so I understand if some of you are going to flame me and say something like I deserve this to happen to me so I can die or something. Until then, any help would greatly be appreciated. It'd help me brake before I hit a car hahah

ANOTHER thing is that a few months ago, a mechanic told me that my brakes were at 30-40%. I haven't heard any squeeling so I don't know if that's the problem or not, but he also said that I need new rotors all around and that they might not be re-surface-able considering that they're a little thin or something.

 

I think you've answered your own question with your statement at the bottom. If you were at 30-40% left a few months ago and you are regularly braking from high speed, your rotors and pads (as well as your brake fluid) must be extremely worn and near the limits. Wear accelerates as the rotors and pads get thinner because there is less material to absorb the heat energy and so they get even hotter. Replace your rotors, pads and fluid.

 

The "farting" noise you hear on take off is the ABS system performing a self test. It's perfectly normal and nothing to worry about. For the shaking, like PA said it sounds like time to get new pads and either replace the rotors or have them resurfaced.

 

Learn something new everyday. Definitely will get the brakes done. Thank you, thank you very much guys!

 

Sounds like your rotors need to be resurfaced or replaced