Greetings from GoVacuum,
It sounds like you have a bad part called the Clutch Rubber Pad Holder Assembly on the inside of your roller brush. I believe that the problem you are having is that the roller brush does not spin, but the belt is properly installed and engaged, correct? This can only be something inside the clutch mechanism in the roller brush itself has gone bad. The easiest way to fix this is to purchase a new roller brush assembly, which can be purchased here; Riccar 8000 Series Roller Brush With Rug/Floor Switch
. I realize that this is a rather expensive part at $43.00, but it may be worth it for you to avoid the aggravation of having to take apart the roller brush piece by piece. To test out this part, and verify that it has gone bad what you need to do is turn the vacuum upside down and remove the bottom plate. Then make sure the vacuum is in the Carpet setting on the Rug / Floor switch on the top of the vacuum. Now while the bottom plate is off, turn the vacuum cleaner on. Can you see the belt spinning on the brush? Is the brush roll itself not spinning? If the belt is spinning on the pulley, but the brush itself is not spinning, this indicates that it's bad.
If you decide that you'd rather just replace the rubber gasket inside of the roller brush, here's a detailed repair solution for you on how to replace this part;
Step 1: Remove the roller brush from the vacuum cleaner completely. If you need help with this step, please see my repair solution for the belt change on your model here; http://www.fixya.com/support/t4184186-replace_belt_riccar
Step 2: Once the roller brush has been removed, turn the brush on it's side, so the metal end that has 2 teeth protruding out is on top, and the end that has the rubber cap is downwards. Use a flat head screw driver to remove the clip on that outside of the brush;
Step 3: Remove the clip on the outside of the brush with a screw driver, then remove the metal end cap from the brush. The entire roller brush is spring loaded, so you'll need to apply some downward force to these parts so they don't just shoot off. It's really the easiest if you lay out the pieces to the roller brush in the order that they were taken off, to make it easier when you are reinstalling these pieces. After removing the metal cap at the end, this is what you should see:
Step 4: There is a small plastic washer underneath of the metal cap. Remove the washer, and the plastic part underneath of the washer that has two teeth protruding outwards. This is how the brush should look after this step;
Step 5: After removing the plastic part with the teeth, the next part of the brush is the metal part which is called the Inside Metal Cam. The Inside metal cam is the part that the actuator arm for the rug / floor switch connects into. Remove the Inside Metal Cam from the brush. This is how it should look after this step;
Step 6: The next part underneath of the Inside Metal Cam is called the Agitator Pulley Clutch. This is the part that the belt rides on. Remove the Agitator Pulley Clutch from the roller brush. This is how it should look after the Agitator Pulley Clutch has been removed;
Step 7: The next part that needs to be removed is called the Agitator Compression Spring which is used to spring load the entire roller brush. Simply slide this spring off the Agitator Shaft, and this is how it should look;
Step 8: After the Agitator Compression Spring has been removed, turn the roller brush on the side, and remove the Agitator Shaft from the roller brush. This is done by simply pulling the other side of the brush end which is covered by a rubber boot. This will remove the long metal shaft which is sticking up. This is how it pulls out;
After the shaft has been removed, the other end of the brush should look like this;
Step 9: The next part that needs to be removed is probably the part that's worn out on your vacuum. The part is called the Clutch Rubber Pad Holder Assembly, Riccar Part Number C012-0400. The way the roller brush works is, when you move the Rug / Floor switch to Floors, the clutch (the parts that you just took apart) loosens up so that the belt is still turning, but the pulley that it spins on is not tight against the brush. When you select the switch to carpets, the clutch then tightens the pulley against the Clutch Rubber Pad Holder Assembly so the when the belt spins on the pulley, it's also now going to spin the brush. Over time this part gets heated up, and the rubber wears down to a point where the pulley will no longer stick to it, which causes the exact problem that you have, where the belt is installed correctly, but will not spin the brush. Simply use a flat head screw driver and pry directly on top of the brush strip, and remove the Clutch Rubber Pad Holder Assembly;
This is how the part looks by itself;
If you're interested in purchasing this part, you may contact your local Riccar dealer, or we can also supply you this part. Once again this part is called the Clutch Rubber Pad Holder Assembly, Riccar part number C012-0400. Please just email me at firstname.lastname@example.org
for pricing on this part if you need it.
I hope that this repair solution was helpful for you. If this didn't fix it, please contact me, I'd be more then happy to try and help you diagnosis this problem further. If this repair solution was helpful to you, please be sure to rate the solution as helpful by clicking the 4 Thumbs Up Icons in the top right hand corner of this repair.
Thank you very much,