i have a 2000 ford expedition xlt (not 4wheel drive) i took it in for an oil change and the guy there told me that my brake pads needed to be changed and that i also needed a ball joint replacement and coil pack. so i got everything done today including an unexpected brake caliper replacement. and now all of a sudden while driving, my brake warning light wont turn off. ive never had this problem before. im assuming it has something to do with how the guy put my break pads in but i know nothing about cars. please help. is this something i should be worried about ? what could be causing this ?