why when i hit the brakes there is a clicking noise coming from my gear box

 

From the actual gearbox, or from the center console area?

If coming from the console area you're hearing the shift release solenoid. This is what keeps you from shifting out of "P" unless the brake is applied.

Once you're out of "P" you shouldn't hear it. There's a "Not In Park" microswitch that prevents it from operating. I suspect the switch isn't working on your car

Cheers
DD