Metro plans to inspect 464 of its rail cars – about 40 percent of its entire fleet – after a brake component fell off a train on the Orange Line Friday.

It’s the same part, a friction ring, that broke off another train two weeks ago and caused massive problems.

But this time, it’s a different type of rail car with a different type of brake system and different manufacturer, raising questions about Metro’s care of the cars.

The incident happened just before noon, Metro spokesman Dan Stessel said, as a train was leaving Stadium-Armory for New Carrollton. The piece knocked some covers off the third rail of the system, he said, but did not appear to cause other damage to the tracks. No one was hurt. The news was first reported by WTOP.

On Dec. 20, a friction ring broke off a train during the morning commute, causing damage to three trains and trapping about 300 riders underground for hours.

That train was a 5000 Series car. After the meltdown, Metro inspected all 190 railcars of that model, which represent about 17 percent of its fleet. It also pulled 16 cars from service that had brake equipment from the same manufacturing batch. But agency officials gave those rail cars a clean bill of health.

Friday’s train was a Breda 2000 Series train. All 3000 and 4000 series cars are the same style and have the same brake system manufacturer.

Stessel said all of the cars will be inspected as they go in for service each day.

He said he expects normal service over the weekend and does not anticipate that the inspections should affect service next week.