Washington ? Amtrak pulled its high-speed Acela Express trains out of service on Tuesday after discovering cracks in shock-absorber assemblies, the latest in a summer-long series of financial and public-image blows to the struggling passenger railroad.

The entire fleet of 18 trains was halted after inspectors discovered the cracks beneath several locomotives.

An Acela high-speed train is shown at Union Station in Washington. Amtrak on Tuesday suspended most of its high-speed Acela Express service so it could inspect the trains for cracks in shock absorbers.

Amtrak President David Gunn said the trains would remain out of service for at least a few days. But if a proposed temporary fix doesn’t work, the trains could be sidelined for weeks.

Nine of the first 11 train sets inspected had problems, spokesman Bill Schulz said. Each train set includes two locomotives, and each locomotive has four of the shock-absorbing “yaw dampers.”

Inspections were continuing on the seven other Acela Express trains, which operate only between Washington, New York and Boston and can reach speeds of 150 mph.

Gunn met Tuesday afternoon with representatives of Bombardier of North America and France’s Alstom Ltd., the train’s manufacturers, to design a repair plan.

“We’re working with the manufacturer on a temporary fix,” Gunn said. “We’ve got to make sure it’s safe.” He said he believed the repairs will be covered under the contract with the manufacturers.

“If the remedy is satisfactory to Amtrak and to federal rail safety officials, a return of the train sets to revenue service would be a matter of days, as opposed to weeks,” the railroad said in a statement.

Amtrak put additional conventional trains into service to try to fill the gap.

Bombardier spokeswoman Carol Sharpe said the company was waiting for its technical team to report back with its findings.

Other Amtrak trains that serve the busy Northeast Corridor, including Acela Regional and Metroliner service, are not affected. “We’re bringing as much equipment as we can into service to make up for the shortfall,” Schulz said.

Amtrak said it would credit passengers for the difference in ticket prices between Acela Express and the trains they take. Passengers were encouraged to check departures by visiting Amtrak’s Web site or calling the company at (800) USA-RAIL.