Officials at the Philadelphia-area PATCO commuter rail line say they have found a part defect that is causing trains to stop suddenly.
They say it happened 43 times from May and July, causing operators to remove passengers from trains traveling between Philadelphia and southern New Jersey.
PATCO General Manager John Rink tells the Courier-Post that the problem is in brake pads.
He says the agency has notified the part manufacturer and is working on temporary solutions.
The problem is affecting only older cars.
The train line is in overhauling all its cars, a process expected to take until late 2016.