Vacuum blows Breaker
If your vacuum is blowing each breaker in your house, it is drawing way too much power, and you need to fix it before you have an electrical fire to deal with.  

For a 20 year old appliance, I would look at the power cord, the brushes and the bearings, as failures in each of those could cause the problem you are experiencing.  Your problem could be something different, like a shorted winding in the motor.  This can happen when the motor overheats, which can happen when using long extension cords, and therefore having voltage drops with increased heating in the windings.  On power head units, sometimes the wires running through the handle will chafe and that can cause a frank short, but that is more rare.

Regardless of what the cause is, you should discontinue testing relying on the circuit breaker, and fix or replace the appliance.