I have a 2000 Intrepid.
When I hit the brakes it sounds like an air value is leaking at the pedal?
This only happens when it gets cold out.

WTF???

 

Your power brakes are vacuum powered. There might be a leak there somewhere. Do you notice a lack of boost resulting in higher pedal efforts? If so, better have them looked at.

 

The brakes are fine with normal temp.
When it gets very cold I hear the air sound, brakes still work fine.

 

May be a seal that shrinks when it gets very cold. Worst case scenario is that the power boost may fail at some point. If that occurs, you'll find yourself stepping really hard on the pedal to stop the car. You could wait until that happens and hope you don't pile up or get it fixed before it fails.

 

Thanks dcotter0579.