While you wait for answers, we may have found some information which could help you.
Click here for Vacuum Cleaner Repair
eureka 4870B smartboss, upright vaccum?
Vaccum, Eureka Model 6998 A?
How to fix idler clamp assembly (hardwood/carpet switch) on Eureka SmartVac?
Eureka "boss" #5893 stops sucking after 10mins?
Older Eureka Boss Possilbe short?
Eureka 4870 vacuum?