U.S. vehicle safety regulators have opened an investigation into complaints of brake problems in an estimated 282,000 recent model year Ford F-150 pickup trucks, the National Highway Traffic Safety Administration (NHTSA) said on its website on Tuesday.

There have been 25 consumer complaints that include claims of “a sudden and complete loss of brakes,” the agency said. The vehicles affected are the 2015 and 2016 model year F-150s that have 3.5-liter engines.

The F-150 is the best-selling vehicle in North America.

In May, Ford issued a recall to fix the loss of braking on 2013 and 2014 model-year F-150 pickups with 3.5-liter engines built from August 2013 through August 2014 — a defect stemming from what Ford said was a loss of brake fluid from the brake master cylinder reservoir into the brake booster.

Complaints about the 2015 model-year pickups “are consistent with the symptoms associated with” that recall, according to NHTSA. But the 2016 vehicle complaints are different, and Ford dealers have allegedly “diagnosed the problem as a failure of the master cylinder,” according to NHTSA.

“We will cooperate with NHTSA on these investigations, as we always do,” Ford spokeswoman Elizabeth Weigandt said in a statement. “Ford is committed to delivering top quality in our vehicles. We continuously evaluate our processes for potential improvements and when the data indicates a safety recall is needed, we move quickly on behalf of our customers.”

Weigandt said Ford has not launched a recall to fix brake issues on the 2015 and 2016 F-150.