My Roomba says to clean the brushes when the brushes are already clean. Is there something to take apart to check? I have already taken the brushes out. I don't know the model number, I think it's the 500 series, black and silver.

You can go to www.iRobot.com . This is the roomba website. You should be able to find replacement parts, customer support, videos or the Roomba product, and more.
When you cleaned your Roomba, did you also clean the wheel wells and outer most edges of the brush brush cartridges? There can be lint, threads, and at my house, cat hair, wrapped around the outermost edges of the brush cartridges.
I hope my suggestions help. If so, please contact Fixya and rate my solution.
Thanks and Good Luck!

Hi. You will need to replace the old/damaged IR LEDs in the front bumpers optical. If you are comfortable using a soldering iron, I can supply you the parts needed.

It clunks because the gears are damaged. You will need to replace the CHM. If you have the red cleaning head module, chm, replace it with the green chm.

The dust build up in these Roomba's do create a problem in all operating phases
Keep in mind if taken apart every 6 months and cleaned inside they will operate like they should

Ok, this is a "Brush Height Adjustment" issue. It will probably work great on a hard surface but on carpet the brushes bog. If you've taken the unit apart already...Sorry....do it again. When you do, you'll see a String which allows the brushes to "Float" on different surface heights. Loosen the screw a little and pull a bit more string through. Re Tighten the screw and put it together enough for a test run. Now reset the roomba.To reset the Roomba, power the Roomba on, and press the Spot, and Dock buttons together for at least 8 seconds. Until it plays a tune. The clock, and any schedule is erased at this time. Try running the Roomba with the dust bin removed to see the brushes spin easier.

Second method, is taking off the bottom cover, and removing the battery. While it's removed, and not plugged into the charger, press the clean button for at least 20 seconds. This will erase the memory. Replace battery, and cover. Run the Roomba to see if the brushes start to spin. You can also remove the brush housing by removing the 4 screws and reseating it, to see if it was a bad connection, since you have the bottom cover off.

pull brush rollers out.pull funny lookin yellow ends off and clean hair ect.out .also pop out front wheel and clean

Roomba 500 Series have a serious problem with hair and other fibers working their way into the drive gears. The resulting resistance in the drivetrain is interpreted by the machine as overloaded brushes. People who experience this problem should complain to iRobot technical support. If the machine was purchase less than a year ago, they should ship a replacement assembly to you at no charge.

I had this problem with my Roomba Discovery. I ran across your question while searching for an answer. My main symptoms were, Roomba hesitated a lot, and the dust bin did not fill. I had plenty of hair wrapped around the brushes and against the filter.
I just finished taking my Roomba apart. I found the motor drive shaft had a LOT of hair wrapped around it and it had climkbed into my gearbox. I took that apart and cleaned all the hair out of the gearbox. My Roomba is back to normal now, filling the dust bin.

before taking apart your Roomba read this!!! First to see if it is a defect or really the brushes, take the brusehs out and run roomba with out them. If you still hear the clicking/ thumping then try taking it apart or call roomba. But if the clicking/ thumping goes away when the brushes are out you're in luck! Take the brushes. The brushes have little yellow nubs... those come out. pull them out, and you will see a lot of hair waiting for you. clean all of the hair out ( tweezers are wonderful for this). Once they are cleaned out put the yellow nubs back on. Put your brushes back in and you're Roomba will be back to business in no time!!!

grrrrr