City Council Chairman Sterling Tucker yesterday unexpectedly was endorsed by the 7,000-member Teamsters Union Local 639, one of the largest private sector unions in the Washington metropolitan area.

Daniel George, who was elected president of Washington's Teamsters local at the head of a reform ticket a year ago, said the union hopes to help Tucker raise $4,000 to $5,000 in campaign contributions through a series of fund-raisers.

George also said that some of the 4,600 Teamsters who live in the city will be working at phone banks for Tucker and driving voters to the polls during the Sept. 12 primary. From 25 to 50 Teamsters volunteers are to begin working in Tucker's campaign by this weekend, he added.

During a press conference outside Tucker's campaign headquarters at 925 7th St. NW, George referred to the substantial union support of Mayor Walter E. Washington and critisized the mayor for running a "colonial-like system" of government.

Last week, the mayor was publicly embraced by the Greater Washington Central Labor Council at a lively, hour-long press conference attended by the top labor union leadership in Washington. The Labor Council represents 145 local unions with a metropolitan membership of 200,000.

"The main reason for this decision (to endorse Tucker)," George said, "is rooted in our sincere belief that unions should first be concerned for what is best for the people of the District of Columbia and not necessarily what is best for unions. Self-interest must come second," George said.

"Our membership felt Tucker is a much better candidate," said George, who said he had polled some of the union's members who live in the city. "Only Sterling Tucker has the experience, expertise, perspective, dedication and freedom necessary to do the job."

Tucker, who made a pointed reference to the fact that previous news reports had said he was not expected to get any union endorsement or support, said he was happy to be endorsed by a union leadership that is identified with progressive reform.

"Here is a union which has been struggling with reform," Tucker said, "and in that alone it stands for what I'm trying to do for the city. That's the kind of support I need, that's enlighten."

Last year, George led a slate of 13 dissident Teamsters members to topple the leadership of Frank DeBrouse after a seven-year struggle between supporters of both men. DeBrouse and other former officials of the Washington Teamsters local are presently under investigation by the U.S. attorney's office of Baltimore for labor-management racketeering allegations and by the Labor Department in connection with possible health, welfare and pension funds abuse.

In response to questions about the endorsement, George said he had been asked by Labor Council president Robert E. Peterson to join in union support of Mayor Washington's reelection effort. Petersen could not be reached for comment yesterday.

In response to George's "self-interest" criticism of union support for the mayor, Ron Richardson, secretary-treasurer of Hotel and Restaurant Employes Local 25 and one of the mayor's strongest supporters, said it was proper for unions to act in their own "self-interest."

George, whose union represents truck drivers, chauffeurs and warehouse workers, also said Mayor Washington's administration was "a colonial-like system" where "the same tired leaders and department heads continue to speak of the past."

Lacy Streeter, the major's campaign manager, said he had "no particular response" to George's criticisms of Washington.

In an 11-page statement, Tucker said the city's two chief agencies dealing with the elderly - the Office on Aging and the Department of Human Resources - are the "perpetrators of a bureaucratic hoax." He described DHR's operation as "chaotic" and its record as "wretched."

He also criticized the mayor for taking too long to appoint key staff members for the Office on Aging, saying, "Inaction carried the day."

Tucker said the service improvements for the elderly could largely bemade by improved staffing and better management. He said that with better management there would be enough money to give $39 extra a month in city aid to about 15,000 District residents who now fall by the amount below the Census Breau's definition of poverty for an individual, which is a monthly income of $217.

Both D. Richard Artis and Albert P. Russo, who respectively, head the city's Office on Aging and DHR, took exception to Tucker's attacks, with Russo expecially objecting to Tucker's proposal to increase the payments to the 15,000 low-income residents.

Russo said that although the city would like to make the extra payments, such a program would cost $7.2 million and that is not now available. "It's one thing to promise the citizens manna from heaven, but it's quite another to produce," he said. Russo said he is certain that savings from better management at DHR could not produce that much.

Sam Eastman, the mayor's spokesman, said the directorship of the Office on Aging was not immediately filled when the City Council created the agency because at first no applicants sought the post and then no qualified people could be found. Later, he said, two people who were offered the job turned it down.