Washington's Metrorail trains are deteriorating so rapidly that $35 million in federal money for maintenance is needed in the next three years to prevent daily breakdowns, the Metro board was told yesterday.

"There are disastrous peak-hour breakdowns that are occurring every day and affecting 75,000 to 100,000 people," said Cleatus Barnett, Metro board member from Montgomery County, who blamed the system's decline in ridership on the frequent delays. "The reliability of that railroad has got to be restored."

Barnett, and the Metro staff, tried to convince the board to approve a first-year application for $14 million in federal money to buy such items as new motors, brakes and seat frames.

The staff's plan included requests for an additional $21 million in the following two years.

Metro has failed in two previous attempts to win federal money from a fund earmarked for construction and improvements, because the government considered the six-year-old Metro system "too new." But, because the BART system in San Francisco began receiving such money after its sixth year and because of encouraging meetings with federal transportation officials, the request was reborn.

However, questions about expanding the capital budget so quickly and fears over the money that Maryland, Virginia and the District would have to supply in the second and third years of the grant stopped the proposal yesterday, as the two Virginia representatives abstained from voting

For any Metro board proposal to carry it must be approved by at least one representative from every jurisdiction.

The first year's local matching amount of $2.8 million, which is 20 percent of the grant, would be covered by current Metro funds, from interest earned on money in the Metrorail construction program.

It was unclear where the next two years' matching funds, approximately $4.2 million, would come from.

"Granted, the situation's critical," said board member Joseph Alexander, of Fairfax, speaking of the need to replace rail car parts. "But it's a matter of putting it in the budget."

A disappointed Tom Downs, one of the District's representatives, argued that the application should be approved, if only to determine whether Metro could win the money.

The board voted to take up the proposal at a special budget session next week, but the problem of maintenance continued to dominate the meeting. After receiving a report that found 103 of the system's 1,800 buses were out of service because of broken engines, the board voted to cancel a contract to buy 50 bus shelters and purchase 16 rebuilt engines instead, at a cost of $210,000.

Additionally, a staff report found that the deterioration in Metrorail service since January was caused by a heavy maintenance backlog, problem brakes and cold weather. The report rejected the notion that service problems were heightened by a policy passed after the Jan. 13 fatal Metrorail accident. Operators were to assume the worst once an abnormality is found, and generally have reacted by taking a train out of service.