I'm just doing this on the fly so I'm not sure if you read what I wrote about a similar issue with the slide pins look for your specific vehicle and make sure the smooth and the one with a groove are in the correct order IE groove top smooth bottom or vice versa and on top of that before buying a new caliper I would and again I'm not sure if you already have the red or did this make sure you lube up all the parts the piston the back of the back of the clipsall places that are going to get friction minus this goes without saying the pad surface that contacts the rotor I know I know but I just got to say it
I know recently doing mine own breaks the slide pins need to be in the correct order as far as Grooved on top smooth bottom or visa versa depending on your own vehicle and mine were out of wack and caused squeling and abnormal where but not until 20 30,000 miles did I start to notice.. hope this helps figured it was worth a reply