I have a 17 sportsman 570. One day the brakes went out and thought it was because of pads being too worn. Changed all the pads and bled system. Still nothing. Brake handle only gets tight when I push foot brake and even then the stopping power isn't there. Any ideas? I'm torn between replacing master cylinder or the caliper. And when I push the hand brake there a swishing sound coming from the lower MC that i never noticed before.