A dissident slate of Teamsters union members is seeking again to unseat the leaders of the largest Teamsters local in the Washington area in a union election this month.

The 13-member dissident slate - similiar to a "reform" ticket defeated in previous election contests - is headed by Daniel George, an outspoken critic of the union's leaders who is challenging Frank DeBrouse, the incumbent president of Teamsters Local 639. George has lost to DeBrouse in earlier union elections.

George's previous efforts to unseat DeBrouse have led to protected proceedings by the Labor Department and in the federal courts, including two U.S. Court of Appeals rulings.

Alleged irregularities in a 1972 union election resulted in a court-ordered rematch between George and DeBrouse. DeBrouse had won the first contest, 829 votes to 531. In the rerun, DeBrouse defeated George again, 811 to 560.

The central issues in this months campaign are similar to those in previous contests. George denounced the local's dealers, in an interview, as undemocratic and alledgely cozy with the management of firms where union members are employed. DeBrouse said his ticket is running as "the experienced slate," with a record of solid gains in contracts and benefits for union members.

Both men say they expect to win. DeBrouse asserted that union members are "fed up" with George's campaigns. George said that his slate is more organized and that he himself is better known than before.

Local 639 claims to represent more than 7,000 truck drivers and others employed at the Safeway stores and Giant Food supermarket chains, United Parcel Service, The Washington Star, and a number of local moving, cement and liquor companies.

Election ballots are scheduled to be mailed to union members next Tuesday. They are to be counted June 24. The American Arbitation Association is supervising the balloting.

The Local 639 election has drawn national attention among dissident Teamsters members. John C. Sikorski, who heads a dissident Teamsters group called PROD, Inc., described the contest yesterday as an "opening shot" in efforts to oust local Teamsters and said a victory by George's slate "would be a tremendous boost for us."

John D. Catlett, who is running for secretary-treasurer on George's slate was among three Teamsters dissidents who field charges with the union's national executive board in April, seeking the removal ot Teamsters president Frank Fitzsimmons.