Hepa Air Purifier

I Have An Air Purifier With A Washable Carbon Pre-filter, Can I Vacuum It Instead Of Washing It Or Would That Damage It? Also It Is A True HEPA Purifier However I'm Noticing There's Dirt All Around The Edges Of The Filters Meaning They Don't Actually Make A Seal And It's Just Blowing Dirt And Dust And Everything Back Out, Is There Any Way I Can Fix That? Duct Tape Maybe?