Brushes spin slowly then when applied pressure they stop

The brushes are usually belt-driven. You may need to replace the belt.

It takes a lot of suction to spin the brush. First make sure the suction is good. Make sure the bag and/ or filters are clean. Replace if necessary. Most turbo tools can be opened up to clean. Most have a lever that allows you to open it up to clean hair, dust, etc from the fan and fan shaft and other areas inside the tool. The tools pick up a lot of hair and debris and some will wrap around the moving parts building pup to the point the brush will not spin fast enough. The same thing can happen to the brush roll on your vacuum so be sure to clean it too and replace the belt at least twice per year.

On those models the brushes are turned by suction.
1. Check the lower tank to be sure its completely closed and sealed.
2. Check the lower tank to be sure the tools filler plate is in place (if you used the tools recently)
3. If both 1&2 ok, manually turn the brushes, if they do not turn freely you may have a stuck turbine or bad brush block.
4. Take the brush block out by releasing the tabs on each corner being careful not to break them.
5. Place a large flat blade screwdriver in the square drive hole that drives the brushes under the machine. Gently turn. It should turn slowly with some resistance. If it turns slowly it is ok. If it turns with no resistance it may be bad as well. If it will not you may be able to break it loose with some even pressure being careful not to strip the hole. If it will not turn or makes a lot of noise replace the Turbine assembly.
6. If the brush block has a broken drive shaft or will not turn replace the brush block.

Here is what that brush block should look like.
http://www.vacuummedic.com/product.php?id=206


Good Luck!

Turn the belt inside out. This problem stems from a design flaw in the mechanism that turns the hoover from bare floor to carpet. After taking it apart I realized that the spring that pushes the belt tight (to make roller spin) is not any where near strong enough to keep the brush rolling. My solution was to turn the belt inside out (there by essentially shortening the belt and allowing enough pressure to be applied to the roller to keep it spinning. Horrible design flaw. I am an engineer and find this pathetic. Hope this helps someone.

There is an air inlet screen behind the brush indicator....if this is plugged with hair and debris, this will cause the brushes to stop spinning....also, if the mackine is upright or if the recovery tank is not in place, then the brushes will not spin.

replace the belt.

Make sure you take off the little cap at the end (the one that spins -- just grab it and pull it straight off) and clean under it too. The rest of the brush may look perfectly clean but what happens is that hair gets stuck under spinning cap and, like a slowly growing washer, it pushes the whole brush toward the gear box. When it gets pushed over enough, the large yellow ring starts to rub against the side of the brush deck making it harder for the motor to turn the brush and you get that "remove and clean brushes" message.

track not set properly in grooves
there could be a clog or the cleaner has built in feature to slow down heads for better cleaning this does it on its own

The brushroll may spin when looking at it but stops when pressure of the floor is applied. The belts stretch, so they look fine but are not. The smell - if it's a rubber smell - would also be the belt. Some, or most, brushrolls can get hair in the ends that could also cause a smell and belt problem.