A new lawsuit accuses Ford Motor Co. of hiding a dirty little secret.

The Dearborn, Mich.-based automaker was sued Wednesday for purportedly selling trucks with defective fuel tank linings during a 10-year period. The lawsuit, which a construction company and its principal filed in a New Jersey federal court, claims the tank linings on Ford’s E- and F-series trucks manufactured between 1999 and 2008 were prone to “separate and flake off,” which would cause clogged fuel systems and loss of engine power. Ford’s F-series pickup is the best-selling U.S. truck.

Additionally, the plaintiffs claim that in 2007, Ford secretly told dealers about the problem, but didn’t recall the affected trucks or offer to repair them for free.

The plaintiffs accuse Ford of fraud, breach of warranty and unjust enrichment, among other charges. They seek class action status as well as compensatory, punitive and treble damages.