Well, I change my headlight bulbs every 2 years if they are good or not, Keep them for spares. The reason is ALL bulbs dim and yellow over time, I treat headlight bulbs like wiper blades. An ounce of prevention You Know !!!
Could be your emergency brake pads, Set the emergency brake HARD and release a few times, This will reset the brake. It's worth a try. I'll bet that is what it is ;)