About 3 weeks back I had my front discs and pads changed. Went for black diamond 6 groove discs and brembo pads. I don't travel far on my daily commute but have been gradually bedding them in. The issue I'm having now is that when I'm braking at about 80-90mph, the car almost slides/sways left to right and right to left. At first I thought it was because I was braking too hard but it happened again and am starting to think something is wrong. Not sure if anyone else has had this before and I am after a bit of advice or people opinion on the matter.