On my teg I was redoing the rear brakes, and I noticed that one of the pin boots is soft and supple, while the other one is rock hard. I'm talkin about the actual in and out motion. Is this how it's supposed to be (to keep the pad at an angle), or is this a faulty caliper... it is like this on both sides, and on both sides it is the top one that is immovable. Thanks.