A clean robot is a happy robot!
Step 1: Background
Dust and debris are big problems for our automated friends. Auto does not mean maintenance free my friends. This particular robot was rescued - off to the landfill it was. It's last owners abused this robot, we almost called Children and Robot Protective Services to make sure no other robots were in the house.
Naturally, the first thing I discovered was the robot's diagnostic mode... this was before I knew such a mode existed. Here's information on Diagnostic Mode for the older generation. Pay close attention to over current warnings as these will cause damage in the long run.
Below you'll see the classic Roomba spiral footprint on my ugly apartment carpet.
iRobot recommends cleaning every 2-3 cycles (the original manual says 5-10 cycles I think). Die hard Roomba owners clean their brushes every use. Not to worry though, it takes a few minutes - much less time than vacuuming would. Cleaning keeps everything running more efficiently, cooler and thus allows a longer robot life.
Step 2: Begin Cleaning
Remove your particle bin. Grasp the small clip, squeeze and pull. Empty if necessary (don't forget the filter) and set aside.
Now, flip your Roomba on its backside.
Step 3: Remove the Vacuum Service Cover
Using your finger - pry at the notch at the back of the robot. The cover should pop off.
Remove any dust inside and set the cover aside.
Notice the interesting eddy patterns caused by the spinning motor and dust slowly clogging from one side.
Step 4: Remove Brush Grille
At the back of the grille you should notice two tabs. Starting with either one, press in on the tab and pop that section of the grille out. Repeat on the second side. It may take some pushing to get it out - but with practice it will become second nature.
Now remove the top middle section and then press in on the sides to remove the left and right section.
The grille should now be out. Clean as necessary and set aside.
Step 5: Remove Cleaning Brushes and Bearing Carrier
On the right side of the brushes you should see a small screw. Carefully unscrew - there's a ring behind it to prevent it from coming out - so unscrew until it stops backing out.
Now, gently pull up the the bearing carrier. The brushes should come up with it. Lift it out of the robot and pull to the right to remove the brushes from the driven side of the robot.
Step 6: Cleaning the Brushes Et. Al.
Originally, the Roomba came with a brush comb. I don't have said comb, but I do have some digits that can do wonders. So, go ahead and use your fingers to pull out any caught hair, fuzz, etc. Once done, I rinsed my brushes under cold water and then dried.
Now remove any tangled bits around the brass bearings and clean off any dirt/debris that may be inside the carrier. Do the same for the driven side of the robot (see picture).
This is also a good time to remove anything that may be caught in the spinning whip brush. This can be removed for cleaning, but I'm not going to do so often because the screw strip easily.
Step 7: Cleaning House
Now, using a moist paper towel or sponge, clean off any dust and small particles. Get in all the nooks and hiding places.
When done, take a peek inside through the particle bin hole. If you see any fuzz or anything, pull it out. Having a toothpick handy helps.
You may also want to peel back the wheel treads and looks for anything hiding in there.
Finally, I used a canned air duster. I sprayed into the particle bin gap under the brush housing etc. The idea is to push everything out the leading edge of the cleaning portion of the robot. Be careful, because this can cause more damage than good - especially if large clumps of dust attach themselves to the motors (which may cause overheating).
Step 8: Front Wheel and Lubrication and Reassembly
Using a razor blade or similar tool, cut out any hair or other debris in the front wheel. It should turn freely.
The mfr says nothing about oiling. But Volkswagen also says my gearbox is oiled for life (oil testing proves otherwise). We're going to oil some friction components with a mineral oil - like sewing machine oil.
Apply some oil the the bearings and bearing carrier. Where moving parts come near stationary parts. Apply a drop around the whip brush. Apply a drop or two into the front wheel. Apply wherever you think it is necessary. Just don't apply too much that it will damage your floors :P
When done, reassemble reverse of assembly. If you had any over current warnings before - check again. A good cleaning typically resolves that problem.