Hoover Bagless Windtunnel (tank tyle) selfpropeled head throws belt; 2nd one doing exactly as the first vacumm.very hard to put it back on .can't even get one room done

try this link below
http://www.ereplacementparts.com/hoover-u6630900-windtunnel-selfpropelled-bagless-vacuum-parts-c-37315_37337_37584.html

The back cover is called the a micro/dust assembly. See #21 here:
http://www.ereplacementparts.com/hoover-u6630900-windtunnel-selfpropelled-bagless-vacuum-parts-c-37315_37337_37584.html


The little sensor should be in the round recess in the top of that assembly. When you are putting the cover back on you have to use a pair of needle nose pliers to push the sensor into the round recess until it is snug. It is hard to do because the wires to the sensor are very short and you have to be careful not to break the wires on the sensor. The sensor is a little microphone that senses the noise of the dirt going through the EDF. The first time I did mine I didn't push it in hard enough and came out of the EDF recess and fell inside the vacuum body.

nylon belt in center of brush underneath . not a hard belt change.

That means that you need to replace the belt. Here is the belt you need for your model.

Hoover Windtunnel Canister Belt

If you turn the vacuum so the bottom is facing up you will see the base plate that covers the roller brush. There will be four screws (usually phillips head), remove the screws and the base plate will lift off. You now have access to the roller brush and belt. Lift the roller brush up and remove the old belt. Place one end of the new belt over the motor shaft and the other end over the roller brush and put the roller brush back in place. Now simply replace the base plate and you're done! This models requires Hoover belt # 38528033 (single) or Hoover belt #40201160 (2 pack). You can get this belt at www.vacbelts.com.

Here's the pages:
http://www.vacbelts.com/hoover-40201160-belt.htm
http://www.vacbelts.com/hoover-38528033-belt.htm

Your beater brush could be frozen. Meaning the bearings are shot. You'll need to replace the brush roller

I have the exact same problem as you have. Have you found a solution since you posted on Mar. 18, 2009? Thank you.

With this self propell series, the entire bottom needs to come apart to re-install the nut. if it is one month old I would highly recommend taking it in for warranty service. What plastic is melted?

I’m happy to assist further over the phone at https://www.6ya.com/expert/robert_b96ba3f038cf317c

Hoover emailed me back right away with a solution and a thorough explanation for a very easy fix. I guess I should have thought of that myself. Oh well, but that did not cost me anything. Now that makes me happy.

Put the V belt on the pulley first, then the flat belt, put it over the motor shaft or pulley, then you have to stretch it to go over the pulley next to the V belt pulley.