This unit uses a small pump to create the vacuum. that pump is made out of an electrical motor that spins a shaft to which a plastic rotor with sliding blades is attached. This shaft and the rotor are encased in a plastic body that holds the bushings for the shaft and the seals for the air ports. If the rotor or the bushing for the shaft got damaged in any way the blades will be thrown out of balance and hit the sides of the casing making the rattle noise. To fix that you will need to completely dismantle the unit and access the pump and see if its failed parts can be reattached or fixed - there are no replacement parts. If you can't fix it then the unit will have to be used as it is for as long as you can - when it will fail for good just buy a new one.
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This unit uses a small pump to create the vacuum. that pump is made out of an electrical motor that spins a shaft to which a plastic rotor with sliding blades is attached. This shaft and the rotor are encased in a plastic body that holds the bushings for the shaft and the seals for the air ports.
If the rotor or the bushing for the shaft got damaged in any way the blades will be thrown out of balance and hit the sides of the casing making the rattle noise. To fix that you will need to completely dismantle the unit and access the pump and see if its failed parts can be reattached or fixed - there are no replacement parts. If you can't fix it then the unit will have to be used as it is for as long as you can - when it will fail for good just buy a new one.