I agree with chief02. The gaskets are either worn or need replacing/adjustment. Don't know how old your trailer is but some owners can handle this themselves. If not up to it, it is something the dealer/rv repair can fix pretty easily. Your problem is not that uncommon.
Ron and Debbie Parker, La Porte, TX
2007 Dodge Ram Hemi 1500, 2011 Chaparral Lite 269BHS 5th Wheel