Took my calipers apart today and gave them a very good cleaning. Easily to do if you got time. Pistons maneuver so much easy after cleaning. Only thing that got me was when you take the calipers apart, there are two rubber washers (seal set) that go around the inside of the caliper jets, both sides. They disintegrated like biodegradable styrofoam packaging popcorn when cleaning with brake fluid. Luckily enough i have a set of bad calipers that i took apart and used the rubber washers from them, and just cleaned them with warm water.