Former NFL defensive lineman Brandon Mebane -- who helped the Seahawks win Super Bowl XLVIII -- says he got screwed over in a deal to buy a Los Angeles mansion ... and now, he's suing to try to rectify things.
TMZ Sports has learned ... the 39-year-old ex-nose tackle filed the lawsuit in L.A. County this week -- some five years after he purchased a property in Encino for $4.85 million.
Mebane says as part of the agreement he made to snag the home from the builders -- which included Roi Edery and Ofir Grushkovski -- they would handle all of the repairs he found following inspection.