I have a Dyson DC07 that is not sucking as well as it should. Taking it apart and comparing it to a working DC07, I've compared the suction just after the pre-motor filter where it would enter the cyclone unit and the difference is marked. It's not a filter issue - both are clean, and it makes no difference if they're swapped. The OTHER big difference is the air outflow at the base of the cyclone unit. The faulty model is blowing a gale out - the working model just has a fairly gentle stream. What seems odd to me is that I'd have thought more air coming out would equal a greater vacuum - but the opposite is true here. Any ideas?
Cyclones get blocked on Dc07, swap them over and compare, it won't be the motor, they either work or they don't.