hey my xB has 12,000 mi. and i wanted to know when i should change the brakes. i kinda have a squeak but i know thats probably from brake dust. let me know. thanks!

maybe the brake pads... which you could do with an allen wrench after you get the wheels off.

take off the front wheels and take a look at the pads....if your pads are like half an inch thick, your ok...if you don't see any pads...your in trouble. try some brake cleaner spray too

Is there a brake level detector on the xB that sends a signal and turns on a light on the dash?

When you hear a squelling noise from your brakes ... your pads should last you aleast 20,000 miles ... it also depending on the way you drive ... if you are hard on your brakes they won't last as long ... you just have to look at them and see how much pad you have left ... if you don't know what you are looking at then take it to the dealer, they should check them for you at no charge.