This is not normal. Anyone with ears knows this isn't right. They are using cheap crap parts. I am getting a new electronic brake booster fitted in my brand new focus ST due to a very similar clicking. You have to fight hard if you want a new one - basically you have to do about £2000 worth of hours fighting to get the £2000 part fitted under warranty.
No more Fords - they are finished as a company in Europe. I have bought 7 Fords in 6 years, used to love them. This is the final straw.
I know this is a Ford Raptor forum, but I am sorry, I had to add my view from the UK. Why would they replace my electronic brake booster if it's meant to be clicky? It is faulty if my rear seat passengers can hear every time I hit the brakes.
Sound familiar? This is my car and my 4th Mk4 focus ST. This is how I knew it wasn't right. I tried an identical one and it was silent, yet they still told me mine was normal.