I've been trying to figure this out for a while I suspect its the brake booster but I'm not 100% sure so here are the symptoms, the first few times I brake its very solid and stops as it should but after that they don't bite as good and I have to stop from a farther distance. I also notice that when I have my foot on the brake, the pedal moves slowly and stops half way. So far here is what I have done to the brakes:

1. new master cylinder
2. new pads and rotors
3. rebuilt calipers in all four corners

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