yrs ago i found a Eureka ESP upright with a full bag that 'blew up', jamming the outer bag zipper. Its Vibra Groomer 1 brush roller was warped & fan chamber was full of dirt. Now its being used to vacuum the 'mud room' & garage entry (from main part of house) carpet
Next would be my Aerus/Electrolux Ultralux C152 plastic canister vac that had dirt all over the entire inside (bag chamber & motor) & the vac smelled like stinky feet because the bag & exhaust filter were rock hard
both vacs have been cleaned & refurbished by me before use