Phillip M Dothan , AL October 06, 2015 Appliance: Frigidaire Dishwasher FDB4315LFC3 Frigidaire Dishwasher Fdb4315lfc3: Wash arm was broken and dispenser cover was damaged. How to replace Lower Spray Arm. Used the videos on AppliancePartsPro.com and changed out the parts. The lower spray arm was still working but I changed it anyway since it is several years old and was probably starting to get clogged. 1 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: 15-30 minutes