1. Check the filter to ensure it is pushed securely onto the unit.
2. Check to see if there are any cracks in the filter/"dummy" filter on the sides or the top, and even the bottom as located in the photos below. Check the whole filter and look at the plastic mold lines for any cracks. Also, check the connector parts of the filter and be sure they are not broken off on either side. Cracks/damage may be difficult to see, so be sure to inspect the filter in a well-lit area or room. If there are cracks the filter will need to be replaced.
3. Make sure the leak isn't actually coming from the bottom of the filter.
4. Make sure the black rubber seal is around the knob of the filter and that it is not ripped or torn.
5. Make sure the filters are clean and in place. If the filters are missing or not in place (the filters must line up like in the first picture below or the machine will not fuction correctly. The filters are keyed to fit into each other and then into the notch on the dirt cup that shows the up arrow and the word filter). the machine will either blow dust (leak air or leak) or not suction properly. This machine has two filters located in the top of the dirt cup. A white pleated filter and a foam filter sits inside the pleated filter casing. These filters are both washable. Be sure the filters are completely dry before putting back into the machine.
6. If the machine continues to leak after checking these steps, please contact BISSELL Consumer Care at 69 Monday through Friday 8:00 am - 10:00 pm; Saturday 9:00 am - 8:00 pm; Sunday 10:00 am - 7:00 pm all EST and a Representative will be happy to assist you.