John for Model Number MTB 2448 DRW Regarding brown sediment in ice maker: definitely not plastic or brass and definitely not 30 years old. This might be the refrigeration line. In the pictures for Part AP2984633, there is a bottom view of a U-shaped tube. That is where the sediment is dripping---where that tube goes into the control(?) box on the front (toward the reefer door).
Answer John, OK, The "U" shaped tube in the diagram, is the mold heater. If that is rusted or has sediment dripping from it, that would be an issue in the icemaker mold, or the icemaker is overfilling, slightly. Start by replacing the ice maker. Thanks for the clarification, Thanks and Good Luck Read More... Answered by AppliancePartsPros.com | Tuesday, December 6, 2011