Issue when braking.

[svtlmr]

Hello Guys.
I have a strange issue that i can not find answer for with the search function so I decided to ask you guys directly.
I have a 2005 X5 3.0i.The car have 93000 mls and recently I notice that when I tap the brake pedal the front left side feels ...uhmmm loose.There is a play somewhere on the front left side that only show when i tap the brake pedal.
When I brake slowly everything is fine, the car stops perfect without any shakes or signs of problems.
When I go over bumps there is no clunking sounds or anything.
Is just when I tap the brake.Very strange and it drives me nuts.I am guessing is some kind of bushings or brake related issue but i am not sure.
I called the dealer and they told me to get the car to them so they can look at it but with a hourly rate of 125$ for labor I really do not want to do it.
Can anyone steer me in the direction of what the problem can be?
Thank you guys.