BUDWEG | How to Repair a Floating Single Piston Caliper - EN 

After replacing the original piston with one from Budweg and o-ring from ATE now the new brake disc (new pads as well) gets hot while driving. I'll measure the diameter and compare with the original one. Thinking to put back the original, if the issue does not go away, because only the tip was rusted. I've used hidraulic grease instead of silicon grease on the o-ring and on the piston and silicon grease on the outside parts like the rubber for the sliding pins. Anything I've done wrong or is it possible the piston is a bit thicker than the original?