Sounds like an issue with the caliper to me. Mine used to do the same thing until the right front caliper seized. I replaced the right front the rubber line going to it and its even now.
Might pull the front wheels off and lube the sliders the calipers ride on. They rust and thats what causes them to get stuck on like mine did. I know this now and every 10k (or every other oil change) when I rotate the tires I lube them up and let em go.
It being 11 years old, its probably time to change the rubber lines going to each caliper, might be part of the issue if something got clogged up in there. Cheap and easy to do (calipers aren't so lube them up and start with the rubber lines first)