The brush guard protects the brushes from falling out of the Roomba during operation, as well as preventing debris from being entangled in the brushes. It is a rectangular black plastic frame with metal rods across it that prevent debris from entering the brush. Over time, the brushes may become entangled with debris, or even dislodged due to an ineffective brush guard. In some cases, the brushes may even fall out o the Roomba. This guide will show you how to replace the brush guard on a Roomba 4160.
Turn the Roomba upside down so that the underside is exposed. The wheels and brushes should be visible.
Identify the brush guard, which is the black rectangular frame that the metal rods are attached to.
Locate the 2 small rectangular yellow tabs on either side of the brush guard, directly adjacent to the blue flap.
Place index fingers on both tabs, and apply slight pressure in the direction of the yellow battery pack.
After the guard hinges up, lift the guard up and away from the Roomba.