Transbus, the federally mandated low-floored vehicle touted by the Department of Transportation as the cornerstone in a plan to make public transit fully accessible for the elderly and handicapped, broke down yesterday.

The malfunction occurred in Philadelphia when no manufacturers bid on the first order of Transbuses, for Philadelphia, Miami and Los Angeles. That set off an immediate cry from handicapped groups and congressional interests for a Justice Department inquiry.

Both American bus manufacturers General Motors and Grumman Flxible - had announced earlier that the federal Transbus specifications made bidding for them impossible. It was not known for certain until yesterday, however, that there would be no bids from foreign manufacturers.

Development costs of the 9-year-old Transbus program have totaled $27 million, according to the congressional office of Technology Assessment. One of the new buses, industry sources estimated, would cost as much as $250,000. A standard new bus today, complete with wheelchair sells for about $120.000. Even with 80 percent federal aid, local transit authorities winced at the purchase price of the Transbus.

The lack of bidders for 530 new buses is an embarrassment for Transportation Secretary Brock Adams, who mandated Transbus, and for Richard S. Page, outgoing chief of the Urban Mass Transportation Administration who will become Washington Metro general manager on Monday. Page and Adams announced the specifications for Transbus in September and said that all new buses financed with federal aid after Sept. 30, 1979, would have to be Transbuses.

Because there were no bids, Adams said in a prepared statement, "I have no choice but to submit those specifications to independent outside scrutiny. I will therefore call on an independent scientific review panel to analyze the bus specifications, performance and costs and to advise me and the public whether this new bus can be produced and built for a reasonable price."

Page said that "We were not able to succeed" in forging a consensus on design and the method of procurement. He said he hoped all interested parties - the manufacturers, the transit industry which opposed the bus, and potential riders would be invited to take part in the independent review.

Dr. Frank Bowe, executive director of the American Coalition for Citizens with Disabilities (ACCD), said he was deeply disappointed by the situation. Bowe said that because 80 percent of the vehicles used in urban mass transit are buses and that buses carry 75 percent of all transit riders, the failure to receive bids was "extremely grave."

He called for a Justice Department investigation and announced that handicapped and elderly groups will meet in Houston May 17 to decide what new actions to take. ACCD has repeatedly praised Adams for pushing Transbus.

Rep. Mario Biaggi (D-N.Y.), chairman of the House Subcommittee on Human Services of the Select Committee on Aging, also called for a Justice Department investigation "into circumstances which led to a decision by major U.S. bus manufactuers not to bid" and said that hearings on the subject will be held as soon as possible. Senior citizens groups also have lobbied hard for Transbus on the grounds that it would be easier for them to board.

Neither GM nor Flxible had comment yesterday. Both have been accused by Transportation Department insiders and members of the handicapped lobby of wanting to recover development costs on new buses of their own design rather than build Transbus. Both have denied that accusation and have pointed instead to the federal Transbus specifications and called them unrealistic.