I don't know about your problem but be careful not to mistake 'clean' looking fluid for good fluid.

Brake fluid is supposed to be flushed/changed every other year under good conditions, and EVERY year in humid climates or lots of in-town/stop-and-go driving or when you're doing brake work (replacing lines/calipers/etc). It sucks moisture out of the air and degrades, and the moisture in it will cause your brake components to rust, like inside your calipers and lines.

It's probably worth a flush just for peace of mind.