out of the blue I had a very hard pedal, and almost no brakes. Did some research and started with a new abs relay. Did not work, found the pump not running. Replaced the pressure switch, pump started running, brakes now started working, except when you panic brake. When you hit the pedal fast it is very diff. to press but if you let off a little you can feel a little click in the pedal and then it will operate normally. I purchaced a new accumulator and installed it today and it still does the same thing. My question is what should I replace now? The pump seems to run and cycle as normal and the brakes work great for normal driving, but if someone slams on the brakes, I need to pump the pedal to get it to stop fast. Thanks for any advice