Replaced front brake pads and now the car stops suddenly and screeches. i cleaed the calipers and lubed them up. I did not apply lube to the front of the pads themselves where they meet the rotor. I never cracked the brake line, as i didnt think it needed to be done. the resivior cap was removed prior to starting to allow fluid to back up when calipers were compressed. upon finishing i pumped brakes till they were firm. this was my last step.