"Why is dust coming out of the back of my vacuum?"に関する回答The blue filter sock that fits over the cage inside the vacuum has probably been removed for wet vacuuming or may have slid down enough to let debris through. This trouble shooting guide may help, but I'd check the filter as a first step.
"Why is water leaking out of my vacuum?"に関する回答It's possible that the bottom part of the vacuum (the black tub) or the hose is damage. You may want to check this trouble shooting guide.