Also make sure the hose from the bag door to the valve and the little spout and orifice it connects to in the door isn't clogged. I find those get dirty pretty fast.Could be the valve for the bag. There is a youtube video showing you how to remove the internal hose or replace the bag lockout valve. Just search youtube for how to change an electrolux 6500 SR control valve. If the bag full light comes on this is your problem.