Joseph T Mayer , AZ November 03, 2014 Appliance: General Electric Dishwasher GSD1300N00BB Ge Dishwasher Gsd1300n00bb: Getting black spots on dishes. How to replace Dishwasher Impeller & Seal Kit. I replaced the Spray arm and the filter, checked under the appliance for a leaking seal and found it dry. took the cover off of the drain and cleaned it out. I also ran the dishwasher with about a cup of bleach in it to sanitize it. 5 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes