At shop i physically checked couple of calipers. I picked the best ones. Checked pins polish and free play. Both were good as brand new. As it was DIY at home, i didn't had any high temperature grease. So i used Protek blue lube. Now checked twice pins movement and bled again whole system. Pistons are also fine. I can easily retract them with screwdriver trick as i don't have any special tools. Only brake booster left now. Will check if pressure can be adjusted(at workshop).