The newly elected officers of Washington's largest Teamsters local capped a seven-year battle yesterday by taking over the local's L Street NW headquarters, after a federal judge ordered the former union leaders to vacate their offices.

The new officers, who had campaigned as a reform slate, said that when they started examining the local's financial records, they found that thousands of dollars worth of checks had been written by the defeated officers since Friday, when the election's outcome was announced. They also discovered requests from the former union leaders for hundreds of days of sick pay, they said.

Frank DeBrouse, the defeated president of Local 639, had issued to himself a $7,700 check for 10 weeks' vacation pay, according to a ledger in the local's office. DeBrouse also left a request for 220 days worth of sick leave pay for his 16 years as a union employee. DeBrouse's claim for sick pay apparently amounts to nearly one years amounts to nearly one year's salary. Accroding to the ledger, DeBrouse's annual salary was $40,040. It was unclear whether his claim for * sick pay would be granted by the new officers.

Daniel George, the local's new president, immediately declared he would take a salary cut. "I can't tell you that amount. But I can't pay myself that kind of money," George said. An audit will have to be conducted, he said, before he can determine the local's financial standing. George's slate had previously accused the former officers of engaging in financial irregularities.

The new officers also found, according to their lawyer, that the local is in debt for 11 auto loans and that it owns a pool of autos with no license plates. The former officers and business agents apparently kept the local's cars at their own homes and canceled the autos' registrations after they lost the elections.

Although DeBrouse's slate was defeated in the union election, DeBrouse had refused to give up his offices until a court order was issued yesterday by Judge William B. Bryant, chief judge of the U.S. District Court here. The former officers' refusal to vacate their headquarters, at 2021 L St. NW, appeared to violate an earlier court order stemming from another Local 639 dispute, Bryant said. The earlier order had limited years - a period that ended Friday - unless they were reelected.

DeBrouse and his slate have contested the election's results in a protest filed with the Teamsters Joint Council for the Washington area.

When the new officers arrived to take over the local's headquarters shortly before 4 p.m., DeBrouse had already left. The new union leaders were shown around the office by Robert A. Moore, former secretary-treasurer. Moore refused to be interviewed and ordered newsmen out of the office. "Just get out. Cut out," he told a reporter. "If he don't clear out," he said to his lawyers, "I'm going to have him cleared out."

George and his slate had attacked the former officers during the election campaign as undermocratic and allegedly cozy with the management of companies where union members worked. George has been seeking to oust the local's leaders since 1970. He was defeated twice previously in campaigns for president and lost a third race for business agent.

The more than 7,000-member local represents truck drivers and other employed at the Safeway Stores and Giant Food supermarket chains, United Parcel Service, The Washington Star and numerous local moving, cement and liquor companies.

Solaman G. Lippman, a lawyer who has represented the former officers, charged in an interview that two U.S. marshals improperly barged into the local's offices and pushed a secretary out of their way when they served Judge Bryant's court order yesterday. George K. McKinney, chief U.S. marshal for the District of Columbia, confirmed that marshals had served the court order but said he could not immediately respond to Lippman's complaints.